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elrojobdugs


Jul 21, 2003, 10:58 PM
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trad... big no no
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ive been climbing for a while but with the same group and they always use a grigri to belay, no matter what... i always use an atc and from what i hear and know using a grigri to belay on trad is extremely dangerous... i dont know that much, but am i right??? why is it so dangerous... am i inclined to say something to these people... the grigri is a god to them
???


vegastradguy


Jul 21, 2003, 11:02 PM
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provided they know what they're doing with it, there's no reason not to belay with the grigri on trad.

the only thing about trad is that you cant always see your climber, which makes you belay by feel more than sight, but if you're competent and comfortable with the grigri, more power to you.

i personally use a reverso, but i'd use a grigri if that's all I had in front of me.


tenn_dawg


Jul 21, 2003, 11:10 PM
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There are different views on the subject.

I personally use a Gri-Gri while climbing trad, have for the last 5 years, and have taken countless falls using this setup. Not to say that it will never catch up with me, but I haven't ever had a single piece pull as a result of the grigri's "static" belay.

If on a single pitch climb, get your belayer to jump like a Gym Rat if you fall. This is the norm in sport and trad climbing, and will result in a very dynamic belay.

If climbing multipitch however, I only use ATC's. When you are clipped into a hanging belay, jumping is obviously not an option, and I must have the option of giving an old fashioned dynamic belay by letting the rope slide through the ATC before locking off.

Undoubtably, some will disagree, probably citing Petzl's phamplett that says the GriGri is not for Adventure, Trad or Aid climbing. There are probably at this moment 50 Gri-Gri's being used by belayers in yosemite Valley however. So take it with a grain of salt and make your own decisions.

Travis


thrillseeker05


Jul 21, 2003, 11:12 PM
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I prefer a Reverso as well, but that doesnt make using a gri gri extremely dangerous. Do they preach to you about what you use? If they want to deal with the pains in the a$$ of using a gri gri then let it be.


sspssp


Jul 21, 2003, 11:40 PM
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This topic has been hashed out several times as well. The idea behind the grigri being dangerous is the fact that it can generate larger forces when catching a lead fall because the rope won't slip. Try searching on "dynamic belay" and you can read all the arguments for and against.

Personally, I think the grigri is fine for multi-pitch, but opinions do vary.


buckyllama


Jul 22, 2003, 12:19 AM
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Extremely dangerous? hardly.

The theory is that because the Gri-gri locks up faster and more securely than a human controlling a simple friction device, the peak loads on individual pieces can be much higher.

The reality is that there are ways around this issue like the belayer jumping a-la sport climbing or using screamers on bad pieces. You are not going to rip out a bomber nut or cam by using a gri-gri.

I don't use a gri-gri on trad mainly because I use double ropes. And on multi-pitch it's just an extra heavy thing you've got to lug around.


tradmanclimbs


Jul 22, 2003, 12:34 AM
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I ocasionaly put up new climbs on lead with all kinds of crazy hook moves and shenanigans and I have often thought that a grigri would be a good thing to have. It takes a LONG time to drill a 3/8th in. bolt by hand from a shiity stance or sketchy hook and it is hell on your belayer to hang out while you drill. This is especialy a concern if your belayer is your significant other :roll: The last rt we put up she brought a book to read while I drilled and tried not to crap my pants :shock: I think a grigri would be perfect for that kind of work but screamers would maby be needed if the gear was suspect.


cedk


Jul 22, 2003, 12:36 AM
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For me, the reason the gri-gri sucks for trad is that the thing costs as much as a yellow alien and weighs much more. I'd rather have the cam.

I confess that I'm not too comfortable with climbing trad above one because of the static belay argument.

If you don't mind the extra weight they are the nicest thing going for belaying your second off of the anchor.


noshoesnoshirt


Jul 22, 2003, 3:26 AM
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i found out (afterwards) my partner was asleep while i lead a two hour aid pitch on el cap. plus all the time you spend with your hands off the rope, digging for a snack or changing the tape or taking photos.
i feel pretty good about using a gri-gri on walls.


elrojobdugs


Jul 22, 2003, 6:03 AM
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thanks i was just wondering what the pros and cons are...


stanagesi


Jul 22, 2003, 12:15 PM
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:shock:

USing Grigri's on trad tat is just stupid. It's a great device for belaying indoors or on sport routes, but over here in UK it's been shown that it can increase the shock load on a piece of pro by 2.5 times.

QUote ' it's not gonna rip out a bomber nut' .Probaly not but it will cetainly increase the chances of it happening, and are all your nut placements bomber???

I own a grigri, they are a fantastic bit of kit for certain jobs but all gear has limitations, and there is no excuse for using one with a leader using naturally placed protection.


tenn_dawg


Jul 22, 2003, 12:23 PM
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:shock:

USing Grigri's on trad tat is just stupid. It's a great device for belaying indoors or on sport routes, but over here in UK it's been shown that it can increase the shock load on a piece of pro by 2.5 times.

Cite a source for that, could ya please? And what exactly is "shock load".

I'd really like to see a study of the force increase on a lead piece if the grigri is used in a fall. So far I haven't seen anything. It's almost like GriGri's are in such widespread use for trad climbing, that no one wants to see a study saying it shouldn't be done.

I'd like to see one.

Travis


redpoint73


Jul 22, 2003, 12:57 PM
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Shock load is the same as impact force or whatever you want to call it. I've heard the term "shock load" plenty of times. Usually in terms of the anchor being "shock loaded" if your setup is extensible and a piece fails. Anyway, I too would be curious to see some studies or accident reports regarding this situation.

I actually don't see a lot of climbers use Grigri's for trad in the northeast. But I think that's mostly because you will need another device if you need to double-rope rappel off the route (I'm not counting that crazy contrived way of double-rope rappelling with a Grigri).

Obviously, using a Grigri for trad is not "just stupid". I imagine many, if not most aid climbers use Grigri's. Of course, that is a situation where the increase on force on the gear is weighed against the threat of your belay falling asleep . . .


traddad


Jul 22, 2003, 1:22 PM
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Unless you are belaying a lead climber off the anchors, there is no such thing as a static belay. Yes, a GriGri will more quickly and reliably lock up, but with slack in the system, friction over pieces, moving/accelerating body weight of the belayer, knots tightening....you get the picture, a truly static belay does not happen.
And another point....with all the new fangled belay devices coming out with teeth, jaws, gums, etc....is the "catch" on those units also becoming more "static"?
I like the Gri Gri. My wife can whip slack out like a cowgirl doing rope tricks and has never given me a bad belay. The issue with needing a second belay device to rappel is problematic, though.
Finally, can anyone tell me how to rappel with a reverso on skinny, slick, dry treated ropes without browning out your briefs? Scary.


markc


Jul 22, 2003, 1:36 PM
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For me, it comes down to a few factors. If I'm trad climbing, I'm most likely doing multi-pitch routes. With all the other gear I'm carrying, I don't want to haul two devices for belaying and rappelling. Then I think of the bulk, weight, and cost of a Gri-Gri. I prefer to take something lighter, more multi-purpose, and affordable.

mark


geezergecko


Jul 22, 2003, 2:01 PM
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Finally, can anyone tell me how to rappel with a reverso on skinny, slick, dry treated ropes without browning out your briefs?

Using the reverso backwards will give you more grip and using it normal with 2 biners will give you the most grip. This is in the Petzl manual. I belay and rap on 8.5mm doubles in backwards mode. That is, the climber side is used for the brake hand and the brake side is used for the climber. Not to be confused with the auto function for belaying a second. Observant climbers will point out that I have the unit backwards but I politely tell them that this is intentional to provide more grip.


redpoint73


Jul 22, 2003, 2:04 PM
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Unless you are belaying a lead climber off the anchors, there is no such thing as a static belay.

People aren't literally talking about a completely "static" belay. The concern is that a Grigri catches "more statically" or "less dynamically" than other devices". An ATC or other tube style device will let a few inches of slack slide through the device before catching the fall. A Grigri allows virtually no slippage befroe camming. The result is a considerable increase in loading on the top piece of pro. The debate is whether or not this increase is enough to pull the trad gear. Of course, a good dynamic belay technique can alleviate the problem as others have pointed out.

The teeth on devices such as the Trango Jaws or ATC XP increase the braking power, but probably not as much as a Grigri. I haven't seen any type of comparison, but from personal observation the "modified" tube devices don't seem to lock as suddenly.


jughead


Jul 22, 2003, 2:08 PM
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the problem with the gri gri is it takes the load instantly with no slippage (Its likened to crumple zones on cars) now when you lower off with any belay device the rope partially melts then hardens again in effect glazing the rope AND the belay mechanisms conventional belays also allow you to feel the rope more as it is not being transferred through a lot of mechanisms, the belayer can feel this extra slippage from the glaze through his atc, bug etc. (but NOT a gri gri) therefore he will know to lock off with more force to give more braking force to counter the slippage but the gri's braking force is constant and in time after a few lower offs you will have a lovely slippy gri gri if you have noticed this which is unlikely then when your partner falls the gri gri WONT lock of with full force in a small fall this might manage but if your partner takes a whipper it will bring new meaning to the word as you watch the rope whip through the gri gri as your mate plunges on to the rocks below is that the price you want to pay to be a dumbass and fall asleep while belaying? if you must use a gri gri only use it as an anchored back up to an atc. or ignore me and have a doze and wake up with your rope missing :shock:


brutusofwyde


Jul 22, 2003, 2:59 PM
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if you must use a gri gri only use it as an anchored back up to an atc. or ignore me and have a doze and wake up with your rope missing :shock:

The problem with run-on sentences is that no one can figure out what the heck you're trying to say.

Why would my rope be missing? don't you tie into the end of your rope when climbing multi-pitch? I sure do.

Grigri is neither more nor less safe than any other device in the hands of an experienced, competent belayer.

That being said, the grigri is useless for rappelling two strands, weighs far more than a tube style belay device, and costs far more as well.


jt512


Jul 22, 2003, 3:39 PM
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the problem with the gri gri is it takes the load instantly with no slippage (Its likened to crumple zones on cars) now when you lower off with any belay device the rope partially melts then hardens again in effect glazing the rope AND the belay mechanisms conventional belays also allow you to feel the rope more as it is not being transferred through a lot of mechanisms, the belayer can feel this extra slippage from the glaze through his atc, bug etc. (but NOT a gri gri) therefore he will know to lock off with more force to give more braking force to counter the slippage but the gri's braking force is constant and in time after a few lower offs you will have a lovely slippy gri gri if you have noticed this which is unlikely then when your partner falls the gri gri WONT lock of with full force in a small fall this might manage but if your partner takes a whipper it will bring new meaning to the word as you watch the rope whip through the gri gri as your mate plunges on to the rocks below is that the price you want to pay to be a dumbass and fall asleep while belaying? if you must use a gri gri only use it as an anchored back up to an atc. or ignore me and have a doze and wake up with your rope missing :shock:

This is an idiotic post.

-Jay


tenn_dawg


Jul 22, 2003, 3:55 PM
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In reply to:
the problem with the gri gri is it takes the load instantly with no slippage (Its likened to crumple zones on cars) now when you lower off with any belay device the rope partially melts then hardens again in effect glazing the rope AND the belay mechanisms conventional belays also allow you to feel the rope more as it is not being transferred through a lot of mechanisms, the belayer can feel this extra slippage from the glaze through his atc, bug etc. (but NOT a gri gri) therefore he will know to lock off with more force to give more braking force to counter the slippage but the gri's braking force is constant and in time after a few lower offs you will have a lovely slippy gri gri if you have noticed this which is unlikely then when your partner falls the gri gri WONT lock of with full force in a small fall this might manage but if your partner takes a whipper it will bring new meaning to the word as you watch the rope whip through the gri gri as your mate plunges on to the rocks below is that the price you want to pay to be a dumbass and fall asleep while belaying? if you must use a gri gri only use it as an anchored back up to an atc. or ignore me and have a doze and wake up with your rope missing :shock:

Jeez buddy. How about a period every now and then. I really want to understand what you are trying to say, but I can't make up from down in this post.

And does anyone know where any tests have been done to show the higher load on lead placements durring a fall while using a Gri Gri vs. using an ATC.

I get the feeling that this stigma is the result of a good bit of conjecture, rather than fact. I will bow to defeat if someone can show me some convincing experimental results, however.

Travis


petsfed


Jul 22, 2003, 3:57 PM
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That being said, the grigri is useless for rappelling two strands, weighs far more than a tube style belay device, and costs far more as well.

Not quite, but close. If you tie some sort of loop at the point the two ropes join (rather like PTPP's method for free hanging fixed lines) and clip this loop to the other strand it can be done. The downside is that you end up with a not that catches on everything, and if you rig it wrong, you die.


traddad


Jul 22, 2003, 4:06 PM
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Thanks for the Reverso info. Maybe I’ll give it another try (and maybe next time I’ll read the instructions ;-) ). As for the great static vs dynamic belay conflagration, these are the things I want from a belay, in order of importance.

1. I want the rope to stop, first time, every time.

Well, honestly, I couldn’t think of anything else that even approached the importance of that one thing.
I climb with a lot of different people, a lot of them Newbies, Noobs, Gumbies, whatever and the ONLY belay device I trust them with is the Gri Gri. I was fiddling in a piece at the White Tanks a while back when I looked down to see my belayer, a PhD consultant, taking her brake hand off the rope to haul in some extra slack. Ouch. She knew better but in a moment of weakness made a mistake that could have killed me if she wasn’t using a Gri Gri (she bought the beer that night).
(side note, even if my partner is using a Gri Gri, I’ll KILL them if they take their brake hand off) The ONLY belay device failure I have ever personally witnessed happened with an ATC. An experienced climber (and a very strong fire fighter) was belaying a 200+ pound beefcake when he popped suddenly and unexpectedly while she was feeding slack for a clip. Her brake hand was very near the ATC and given the surprise etc., by the time she got her hand clamped, the rope whipped through, burning her hand almost to the bone. He sustained a blown knee and she ended up without the use of her right hand for a long while.
It’s easy to teach someone to belay a leader using a Gri Gri. It takes maybe five minutes of practice to get the feeding slack thing down. While I personally use an ATC, I like it when the smaller climbers I often climb with use a Gri Gri.
As for shock loading trad gear, If I’m on a trad climb where I’m worried about the strength of placements, I’ll have an experienced belayer in my corner, I’ll take EXTRA care to place my gear (as opposed to my cavalier, throw it into the crack and go attitude ;-) ) and use screamers and my nice, spongy, boingy, bungielike lead rope, which, incidentally, is DESIGNED to limit the shock of a fall.
There are places for Gri Gris. If you don’t like them, don’t use them.


jt512


Jul 22, 2003, 4:08 PM
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And does anyone know where any tests have been done to show the higher load on lead placements durring a fall while using a Gri Gri vs. using an ATC.

I get the feeling that this stigma is the result of a good bit of conjecture, rather than fact. I will bow to defeat if someone can show me some convincing experimental results, however.

I don't know where any tests have been done, but I have seen specific numbers quoted in papers and books for the braking forces of ATCs and Grigris. I doubt that those numbers were just made up.

There is no question, though, that grigris have greater braking power than ATCs. ATCs allow rope to slip when the force exceeds approximately 500 lbf. That is a design feature to limit the impact force on anchors. In contrast, the grigri is designed not to allow rope to slip through, though it will, slightly, at a sufficiently high force. The numbers I've seen quoted vary from 900 to 1400 lbf, probably depending on the specifics of the experiment, such as the rope that was used.

-Jay


jt512


Jul 22, 2003, 4:14 PM
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I climb with a lot of different people, a lot of them Newbies, Noobs, Gumbies, whatever and the ONLY belay device I trust them with is the Gri Gri.

I see people saying that a lot. To those of you who say this I have a question. Grigris haven't been around for that long. What would you have done to insure your safety climbing with a newbie if Grigris hadn't been invented yet?

-Jay


orangekyak


Jul 22, 2003, 4:23 PM
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My wife can whip slack out like a cowgirl doing rope tricks and has never given me a bad belay.

I'm having a hard time envisioning this ... photos would help. jk, couldn't help myself :roll:


sspssp


Jul 22, 2003, 4:35 PM
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There is no question, though, that grigris have greater braking power than ATCs. ATCs allow rope to slip when the force exceeds approximately 500 lbf. That is a design feature to limit the impact force on anchors. In contrast, the grigri is designed not to allow rope to slip through, though it will, slightly, at a sufficiently high force. The numbers I've seen quoted vary from 900 to 1400 lbf, probably depending on the specifics of the experiment, such as the rope that was used.

Right. But as was already pointed out, this is only if the grigri is directly hooked to the anchor. If you are belaying with the grigri attached to your waist, you can't generate more force than body weight (ok, as somebody pointed out--if you are being accelerated, you can produce more force than your weight, but it won't be much). This means if you catch a fall with a grigri, you might get lifted off the ground but you won't be applying much more than a few hundred pounds (unless or until you come tight on your anchor or you get lifted all the way up to the first bolt).

These "tests" with the grigri are usually performed with the grigri attached to a static anchor. But that isn't how people actually use them.


tenn_dawg


Jul 22, 2003, 4:40 PM
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In reply to:
And does anyone know where any tests have been done to show the higher load on lead placements durring a fall while using a Gri Gri vs. using an ATC.

I get the feeling that this stigma is the result of a good bit of conjecture, rather than fact. I will bow to defeat if someone can show me some convincing experimental results, however.

I don't know where any tests have been done, but I have seen specific numbers quoted in papers and books for the braking forces of ATCs and Grigris. I doubt that those numbers were just made up.

There is no question, though, that grigris have greater braking power than ATCs. ATCs allow rope to slip when the force exceeds approximately 500 lbf. That is a design feature to limit the impact force on anchors. In contrast, the grigri is designed not to allow rope to slip through, though it will, slightly, at a sufficiently high force. The numbers I've seen quoted vary from 900 to 1400 lbf, probably depending on the specifics of the experiment, such as the rope that was used.

-Jay

What it comes down to, it the force felt at the belayer.

I have a feeling that the force felt at the belay device rarely exceeds 500lbs. I do not know this for certain, but for a moment lets say that in 90% of lead falls, the force felt at the belay is less than 500lbs.

In this situation, the "staticness" (for lack of a real word) of the belay device is a moot point. As long as the force felt at the belay is less than 500lbs, an ATC and a GriGri will cause identical forces to be exerted on a lead placement.

Now, for the other 10%. In a situation where a high factor fall occured, causing more than 500lbs of force on the belay device, ATC's and GriGri's will start to differ. How much is the question.

When the forces on the ATC exceed 500lbs, the device will allow some rope to slip, we have established that. A question that arises, however, is how long of a period of time are these >500lbs forces felt, and what length of rope is allowed to slip.

It is entirely possible that in a high factor fall, the force at the Belay device only exceeds 500lbs for a half a second, resulting in a 6 inch slip of rope. If this is the case, I don't believe that this would result in a statistically significant load decrease on a lead placement.

I have no numbers to back this claim, but I believe it to be well founded. Perhaps there is not as big a differance between a locked off GriGri and an locked off ATC as has been percieved.

Travis


hammer_


Jul 22, 2003, 4:52 PM
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If your a confident belayer you shoould be using an atc. The reason for this is that you have control over where the falling leader ends up. By letting a little more rope slip through your atc before locking off you can allow the leader to miss that nasty ledge or whatever. With a grigri it locks off and thats it, you can only hope for the best.

just my 2c not yours.


tenn_dawg


Jul 22, 2003, 4:53 PM
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Another point that must be raised has to do with the technique of giving a deliberate dynamic belay.

Not many people use this technique, but it is a good one, nonetheless.

If your leader takes a fall above a manky piece using an ATC, one dynamic belay technique is as follows.

1. Hold the rope deliberately with a stiff arm forward of the ATC, allowing the rope to slide through the device and your hand at the onset of force.

2. Then quickly and deliberately, bring your hand back to the lock off position, stopping the fall.

This is a difficult technique to master. Far more difficult than jumping, and has limited use. You want to be aware that you can extend the fall by as much as 20' in a moment using this technique, and should be aware of the possible consequences. For it to work effectively, you need to be PLANNING on using it, and be prepared to do what you have to do.

This is a slight tangent to the argument at hand, but is relevant in the sense that this technique is not possible with a GriGri to my knowledge.

Travis


geezergecko


Jul 22, 2003, 5:37 PM
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Suppose you are using a gri-gri to belay a trad leader. And suppose that for whatever reason the top piece fails in a fall and you have an epic. Let's even say that its not the gri-gri's fault. How are you going to explain that using a piece of equipment against the manufacturer's express recommendations didn't cause the accident? Now I have nothing against the gri-gri. I use them regularly for top roping. But to be stuck in a bad situation where you did something unorthodox? Nah.


jt512


Jul 22, 2003, 5:45 PM
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In reply to:
Suppose you are using a gri-gri to belay a trad leader. And suppose that for whatever reason the top piece fails in a fall and you have an epic. Let's even say that its not the gri-gri's fault. How are you going to explain that using a piece of equipment against the manufacturer's express recommendations didn't cause the accident?

Explain to whom? What's your point?

In reply to:
Now I have nothing against the gri-gri. I use them regularly for top roping. But to be stuck in a bad situation where you did something unorthodox? Nah.

Many trad climbers belay with grigris. I don't, but I'd hardly call it unorthodox.

-Jay


tenn_dawg


Jul 22, 2003, 5:45 PM
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In reply to:
Suppose you are using a gri-gri to belay a trad leader. And suppose that for whatever reason the top piece fails in a fall and you have an epic. Let's even say that its not the gri-gri's fault. How are you going to explain that using a piece of equipment against the manufacturer's express recommendations didn't cause the accident? Now I have nothing against the gri-gri. I use them regularly for top roping. But to be stuck in a bad situation where you did something unorthodox? Nah.

It's not unorthodox. Grigri's are used trad and aid climbing every day by many people.

I believe that it is a distinct possibility that a GriGri is not any worse of a belay device than an ATC for belaying Traditional routes. My reasoning is above.

I would really like to see some specific testing that measures the force on the top piece of pro in a lead fall situation using a Grigri and and ATC. I am sure at a point that there is a difference, but I don't believe it is as substantial as has been implied.

Travis

edit, me and Jay posted at the same time, sorry about the repeated points.


buckyllama


Jul 22, 2003, 6:47 PM
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[quote="geezergecko"]Suppose you are using a gri-gri to belay a trad leader. And suppose that for whatever reason the top piece fails in a fall and you have an epic. Let's even say that its not the gri-gri's fault. How are you going to explain that using a piece of equipment against the manufacturer's express recommendations didn't cause the accident? Now I have nothing against the gri-gri. I use them regularly for top roping. But to be stuck in a bad situation where you did something unorthodox? Nah.
And suppose that your belayer was using an ATC, and suppose that a touron on an overlook tosses a rock off the top and knocks them unconscious (fortunately they were wearing a helmet, otherwise they'd have been killed of course). Your adherence to orthodoxy has just left you without a belay.

I'm not saying that either case is likely, but it's easy to construct scenarios where one thing or another may play a part in an accident. Competency in the environment and familiarity with both the systems and the gear is the best way to ensure safety.


geezergecko


Jul 22, 2003, 8:03 PM
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My apologies if my prior posting rubbed some people the wrong way. It's just that Petzl does not recommend using the gri-gri for trad. Now it could be that they just want to sell more reversos. Maybe not. If I do something that the manufacturer (Petzl) says that I shouldn't do then I would have second thoughts. And if the possible consequences could be tragic then I have third thoughts. I understand that many people ignore Petzl's advice and most if not all of these people are way more experienced than me. It was just one of those things that struck me as being odd. Live and learn I guess.


elrojobdugs


Jul 22, 2003, 8:15 PM
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i feel comfortable (and i guess my friends do) with me belaying with an atc... but im not really comfortable with them belaying unless its a grigri... and some people have told me that on trad its dangerous... ive never had problems of any sort with a grigri on trad and im gonna keep on using it... im just wondering what rc.com people thought... seeing as how some of you must have some climbing experience haha.


traddad


Jul 22, 2003, 8:31 PM
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There is something about the very concept of a “dynamic” belay (or the active attempt to give one) that makes me more than a little squeamish. First, the jumping thing. Do you REALLY mean for people to leave their feet and possibly lose control of their own safety (and thus, yours)? I can see this in sport areas with nice, level ground below the climbs, but in a place where the belay stance consists of a 1 foot square ledge, boulder, etc, I’d like my belayer to stay upright and conscious. I have used a method where I drop my hips as soon as my partner pops and then allow his/her weight to raise me back up, but I never leave my feet. Is that what you really mean?

Now, active belays at the belay device: Shudder! Like what happened to the belayer in my previous post, I worry that if you let the rope slip through the device a “little” you are increasing the possibility of losing control of the rope all together. Once the rope slips in a high energy situation, it MUST be harder to stop than if you concentrated on not letting it slip in the first place. This would be especially true given the forces created by high fall factors.

OK, call me paranoid, but all I want my belayer and belay device to do is stop my a$$ from hitting the ground. All the rest is gravy. I’ll manage the gear placements and make sure, to the best of my ability, that they won’t blow (screamers, extensions, doubling up, GOOD PLACEMENTS). I’ll take responsibility for my flight plan, also. The last thing I want is my belayer trying, from the ground, to estimate if I’m going to hit a ledge or something and then slipping the rope to try to prevent it. Part of my job as leader is to know what is under me when I fall.

As for what anyone did when climbing with Gumbies before Gri Gris; that’s a moot point. Gri Gris are here. Of course I could quote the old Chamonix (spelling?) guide saying: “The leader must not fall!”


markc


Jul 22, 2003, 8:45 PM
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In reply to:
i feel comfortable (and i guess my friends do) with me belaying with an atc... but im not really comfortable with them belaying unless its a grigri...

Care to elaborate on that part a bit? I realize it's a little off-topic, but this made me curious. Are you significantly larger than your partners? Do you climb with people suffering from narcolepsy or ADHD? I don't know why you'd feel comfortable belaying with a certain device, but not want to be belayed on the same piece of equipment.

mark


redpoint73


Jul 22, 2003, 8:58 PM
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In reply to:
I looked down to see my belayer, a PhD consultant, taking her brake hand off the rope to haul in some extra slack.

Apparently not a PhD in belaying. Why in the world would you need to take your brake hand off while hauling in slack with ANY device? Makes you wonder how many times she did that while you WEREN'T looking . . .

In reply to:
I have ever personally witnessed happened with an ATC. An experienced climber (and a very strong fire fighter) was belaying a 200+ pound beefcake when he popped suddenly and unexpectedly while she was feeding slack for a clip. Her brake hand was very near the ATC and given the surprise etc., by the time she got her hand clamped, the rope whipped through, burning her hand almost to the bone.

Sounds like belayer failure, not belay device failure.


sticky_fingers


Jul 22, 2003, 9:22 PM
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[quote="buckyllama"]
And suppose that your belayer was using an ATC, and suppose that a touron on an overlook tosses a rock off the top and knocks them unconscious (fortunately they were wearing a helmet, otherwise they'd have been killed of course).quote]

This is one of the main reasons why I use a gri-gri. For those of you who missed buckyllama's origial post it or need this to be summed up, I'll do so in one word...

"R O C K !"

Face it, no belayer ever watches their partner 100% of the time. You might have to fiddle with the rope, your neck is killing you, whatever, there are a miraid of reasons why we look away, if only for 1-2 seconds. In that time, gravity's still working at 9.8 m/s so it's quite possible for your partner to accidently dislodge something and have it hit you before you can react. If you get knocked out, then you really don't care much about anything, but if you're conscious and really messed up, you're gonna wish you had that oh-so heavy, budget draining belay device. Isn't your partner's safety worth it?


alpnclmbr1


Jul 22, 2003, 9:26 PM
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The main reason not to use a gri gri for multi pitch trad is that it is way too heavy and bulky. The static factor is real to, and the evidence is good enough for me. (I will find some later)

As far as purposely letting the rope slip through an atc type device, I have never met anyone that actually tried to do this. I have seen people do this with a gri gri by holding the cam open. It is easy to recover with a gri gri, it is not that easy with an atc type device.

If you build your anchor out of slings and belay off your harness, it is possible to have a static anchor system in a factor two fall.

The tightening of a knot and give in your harness been shown too at most minimally effect shock loads. This belief is more or less a myth.


hammer_


Jul 22, 2003, 9:37 PM
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OK so your belayer's knocked out, now what do you do? untie and down climb? untie and keep climbing? stay in the middle of a crux move and wait for help that may or may not come? If your belayer is using an atc, it is possible to leave your top piece in and downclimb in relitive safety due to rope drag through his/her atc. You can also set up an ancor, pull some extra rope and rap down to the injured belayer. Don't try any of this at home kids! it's not safe.


alpnclmbr1


Jul 22, 2003, 9:45 PM
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Chris Harmston wrote
In reply to:
The MH is one of the most static belays available. This can be very
dangerous when you must rely on the dynamic belay. In trad and ice
climbing the MH can be very dangerous because it will increase the loads
felt by the top anchor.

Different post
(snip)
Here is another example of some "uncontrolled" testing I have been
involved with.

Last winter Craig Luebben and I conducted some drop tests on ice. Craig published an article in Climbing Mag on some of these results and results of his static tests. I have also written an article on static tests I have conducted in the lab (email me if anyone wants a copy). Anyway, we set up our tests under the bridge in Ouray. This was in pretty bad ice actually and for the most part the gear did not hold. Our setup was with a static belay, a new 10.5 mm BD rope, fall factors in the 1.5 to 1.8 range, and 185 pounds of steel. With this setup the only thing that actually held was a 10 cm screw. Everything else ripped out OR carabiners broke! I attribute this to the bad ice and that the 10 cm screw that held was probably in the only good ice we found.

We decided to conduct a series of tests where we used the same section of rope over again. The first three tests the gear ripped out. On the fourth drop we about keeled over in disbelief. We had a Snarg as the test piece connected to the rope with a draw with BD QS2 biners. A few feet below this was two equalized screws (BD and a Grivel). They were equalized with a single 24" sling and a locked Big Easy was connected to the rope. The biner on the snarg broke, the hanger on the Grivel screw sheared along its long bend, then the big easy locked biner broke! This is three pieces of hardware that broke on one fall. Now, I am assuming that these were not defective products (a solid assumption based on my knowledge of all the gear and the systems to produce it, and a review of the fracture surfaces of the parts we actually recovered). This means that the forces generated were well in excess of 5000 pounds (multiple times!). Now the tricky part. Conducting a static test on a new rope with the same diameter with the same type of knots caused the rope to break in the 3500 pound
range. I don't know why the gear broke and why the rope did not. There was about one hour between drops so the rope had some reasonable time to recover.

Now the good news. When we placed an ATC in the system (i.e. some dynamic aspects) every test we conducted held except for a couple of tests with Spectres.

What does this mean? Dynamic belays are your friend! Climbers have known this for about a century now. Many climbers today do not understand this very well. This is why I am relating these types of info to this news group. I am purposely trying to get this group to discuss this stuff in detail and learn something from it.
(snip)


sticky_fingers


Jul 22, 2003, 10:11 PM
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Too heavy and bulky??????
gimme a break
i just went on REI's home page where they list a BD ATC (not XP) as weighing
49 grams
and a gri-gri weighing
225 grams

Bottom line: A gri-gri is only 176 grams heavier than an ATC.

Now...I'm gonna be generous here and assume a (light) 150lb trad climber. Converting that to grams is 68,038.86 grams. How much is the difference of a gri-gri again? The additional weight of a gri-gri over this person's bodyweight amounts to 0.25% of their bodyweight (even less if they're heavier). If an additional 0.25% of your body weight is too heavy for you to carry, get off the rock. Besides, YOU'RE BELAYING not leading. If the only reason you can't second a climb is because you have to schelp a gri-gri, then you have other problems.

Bulky? what and carrying a rull rack is like a second skin? remember you're belaying. when you climb (if you follow) you begin with NO gear and pick it up as you go. Most likely you'll end up with less than the full rack because the leader probably carried more than he/she needed to.

I'm not trying to sway anybody's opinion, I'm just trying to thow out the arguments that's it's too heavy and bulky.


traddad


Jul 22, 2003, 10:45 PM
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Quoting Hammer: OK so your belayer's knocked out, now what do you do? untie and down climb? untie and keep climbing? stay in the middle of a crux move and wait for help that may or may not come?

Giggle......

I take it that when you pull a block off in a fall and it splatters your belayer's brains, you would rather just go on hurtling toward the earth until that sudden stop at the end. The friction of an unattended ATC would probably just allow you to live long enough to appreciate how much pain you are in.

Yes, I would rather wait, prusik, holler, etc....anything but take a dirt nap.

Here's a challenge to the enginerds out there. Find some way to measure impact forces in a realistic belay situation (read: human, harness, rope, slings, rope drag, gear in the loop) using both the gri gri and an ATC. I figure, given the complexity of the set up and all the drag inputs and general slop in the system, there will not be a real, substantive difference.


traddad


Jul 22, 2003, 10:54 PM
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RP73 sez...
"Apparently not a PhD in belaying. Why in the world would you need to take your brake hand off while hauling in slack with ANY device? Makes you wonder how many times she did that while you WEREN'T looking"

I never said that intuitive ability was positively correlated with education.....
Instead of sliding her brake hand down the rope in a cupped position, she was taking it completely off and moving it down. She doesn't do that any more :twisted:


jt512


Jul 22, 2003, 11:18 PM
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In reply to:
The main reason not to use a gri gri for multi pitch trad is that it is way too heavy and bulky. The static factor is real to, and the evidence is good enough for me. (I will find some later)

As far as purposely letting the rope slip through an atc type device, I have never met anyone that actually tried to do this.

Not true. You've met me. Though the master of this technique is Tom Lindner.

In reply to:
I have seen people do this with a gri gri by holding the cam open.

That's a really bad idea. It would be almost impossible to control the amount of friction using the handle in the event of a fall.

In reply to:
It is easy to recover with a gri gri, it is not that easy with an atc type device.

It's very easy to stop the rope with an ATC. You simply move your hand into the full braking position. Keep in mind that you have control at all times. You don't let the rope run at full speed. The device is always providing some friction; you decide how much by the angle between the two strands of rope. If you start with the two strands about 60 degrees apart and smoothly bring your hand down to your hip, you will let a couple of feet of rope through the device, gradually stopping the fall.

-Jay


jt512


Jul 22, 2003, 11:38 PM
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In reply to:
There is something about the very concept of a dynamic belay (or the active attempt to give one) that makes me more than a little squeamish.

What makes me squeamish are climbers who think dynamic belaying is unnecessary.

In reply to:
First, the jumping thing. Do you REALLY mean for people to leave their feet and possibly lose control of their own safety (and thus, yours)?

I mean for them to leave their feet and not lose control. You don't need to be on your feet to maintain control of the belay. You need your hands for that. And you don't need your hands to control your landing; you need your feet for that. Thus, by means of the Principle of Independent Hand and Foot Action you can control the belay while jumping.

In reply to:
I can see this in sport areas with nice, level ground below the climbs, but in a place where the belay stance consists of a 1 foot square ledge, boulder, etc, Id like my belayer to stay upright and conscious.

The belay stance has to be taken into account. As with most everything in climbing there is no one way to do anything that applies universally.

In reply to:
I have used a method where I drop my hips as soon as my partner pops and then allow his/her weight to raise me back up, but I never leave my feet.

I have done this also, especially near the ground on sport climbs. In a sense, it is the best of both worlds: you both shorten the fall and give a dynamic belay.

In reply to:
Now, active belays at the belay device: Shudder! Like what happened to the belayer in my previous post, I worry that if you let the rope slip through the device a little you are increasing the possibility of losing control of the rope all together. Once the rope slips in a high energy situation, it MUST be harder to stop than if you concentrated on not letting it slip in the first place. This would be especially true given the forces created by high fall factors.

See my previous post. You never let the rope run at full speed.

In reply to:
OK, call me paranoid, but all I want my belayer and belay device to do is stop my a$$ from hitting the ground. All the rest is gravy. Ill manage the gear placements and make sure, to the best of my ability, that they wont blow (screamers, extensions, doubling up, GOOD PLACEMENTS). Ill take responsibility for my flight plan, also. The last thing I want is my belayer trying, from the ground, to estimate if Im going to hit a ledge or something and then slipping the rope to try to prevent it. Part of my job as leader is to know what is under me when I fall.

But let me guess: you rarely fall on lead while trad climbing, which is why your philosophy works for you. But ask a trad leader who is routinely climbs at his limit and takes falls on hard trad. I'll bet he'll disagree with you about the importance of dynamic belaying.

In reply to:
As for what anyone did when climbing with Gumbies before Gri Gris; thats a moot point. Gri Gris are here.

The issue might be moot, but there is a lesson to be learned, so I'll ask again: How did we manage to lead safely with beginners as our belayers before we had grigris? The question can be answered in four words or less.

-Jay


alpnclmbr1


Jul 23, 2003, 12:49 AM
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In reply to:
In reply to:
The main reason not to use a gri gri for multi pitch trad is that it is way too heavy and bulky. The static factor is real to, and the evidence is good enough for me. (I will find some later)

As far as purposely letting the rope slip through an atc type device, I have never met anyone that actually tried to do this.

Not true. You've met me. Though the master of this technique is Tom Lindner.

As I recall you were not using an atc when we were sport climbing.
Are you saying that you advocate that technique as a replacement for jumping? If I had known you did not like to jump I probably wouldn't let you belay me on a route I could fall on. I certainly wouldn't think you would try to use that technique in combination with jumping.
It is true that I have never known anyone that I have climbed with in many years that advocated that practice.(slipping an atc) Is Tom using that technique since he blew his hip out? If I want to give a dynamic catch I use a gri gri or atc and jump, and so does everyone else I know.

In reply to:
I have seen people do this with a gri gri by holding the cam open.

That's a really bad idea. It would be almost impossible to control the amount of friction using the handle in the event of a fall.

Some of the best climbers I know do that all the time doing hero jumps off the anchors with forty plus foot falls. They do not use the handle, they just depress the cam and it provides the softest catch possible with the least amount of swing. You would have to be able to jump twenty plus feet to match what they were doing. Something that is not usually practical
In reply to:
It is easy to recover with a gri gri, it is not that easy with an atc type device.

It's very easy to stop the rope with an ATC. You simply move your hand into the full braking position. Keep in mind that you have control at all times. You don't let the rope run at full speed. The device is always providing some friction; you decide how much by the angle between the two strands of rope. If you start with the two strands about 60 degrees apart and smoothly bring your hand down to your hip, you will let a couple of feet of rope through the device, gradually stopping the fall.

-Jay

I don't see a point in doing that. The most you could let slide is a foot or two of rope, whereas with a jump you can do four to ten feet of rope without a risk of loosing control of the rope.


alpnclmbr1


Jul 23, 2003, 1:04 AM
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In reply to:

Bottom line: A gri-gri is only 176 grams heavier than an ATC.
176 plus the 49 gram atc you have to carry for raps, plus a biner to hold the atc. That adds up to 275 grams.

With that I could carry a 00 tcu, 0 tcu and two green aliens and still save weight.
I have spent a lot of money making my rack as light as possible, neutrinos etc.
Have you ever tried to do a squeeze chimney with a gri gri on your harness?


jt512


Jul 23, 2003, 1:17 AM
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In reply to:
In reply to:
In reply to:
As far as purposely letting the rope slip through an atc type device, I have never met anyone that actually tried to do this.

Not true. You've met me. Though the master of this technique is Tom Lindner.

As I recall you were not using an atc when we were sport climbing.
Are you saying that you advocate that technique as a replacement for jumping?

I think the truth is that jumping is a second-rate form of dynamic belaying. Climbers have been giving dynamic belays by letting rope slip thru the device for a long time before sport climbing came about. You can't jump at a hanging belay, but you can let rope slip through your belay device. Jumping mainly is for sport climbing, where the routes are single pitch and the ground is flat.

In reply to:
If I had known you did not like to jump I probably wouldn't let you belay me on a route I could fall on.

I usually use a grigri to sport climb and jump to dynamically belay. However, I switched to the grigri for lead belaying outdoors just a few years ago, and prior to that I either jumped or let rope through the ATC. I never jump and let rope through simultaneously, but I have let rope through while taking a couple steps forward to make the belay more dynamic.

In reply to:
Is Tom using that technique since he blew his hip out? If I want to give a dynamic catch I use a gri gri or atc and jump, and so does everyone else I know.

No, Tom thinks that grigris are for "people who like to climb stoned." He actually uses a Figure 8 (in rappel mode) to belay, not an ATC. With practice, with an ATC, you can let out as much or as little rope as you want. With a grigri you are limited by the amount you can jump. You actually have more flexibilty and control with an ATC than with a grigri.

In reply to:
In reply to:
It's very easy to stop the rope with an ATC. You simply move your hand into the full braking position. Keep in mind that you have control at all times. You don't let the rope run at full speed. The device is always providing some friction; you decide how much by the angle between the two strands of rope. If you start with the two strands about 60 degrees apart and smoothly bring your hand down to your hip, you will let a couple of feet of rope through the device, gradually stopping the fall.

-Jay

I don't see a point in doing that. The most you could let slide is a foot or two of rope, whereas with a jump you can do four to ten feet of rope without a risk of loosing control of the rope.

Like I said above, you can let out as much rope as you want using an ATC and at any speed you want. It takes practice and a belay glove. You vary the speed with the angle between the ropes, and the length by how fast you bring your hand down to your hip. You do not lose control of the rope. The ATC stops the fall, not your grip strength. Even with the rope running through your hand, if you bring your hand back to your hip, the ATC locks up.

-Jay


alpnclmbr1


Jul 23, 2003, 2:00 AM
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Jay,
I wouldn't let someone belay me using that technique and if I saw someone keeping their hand in front of the device, I wouldn't fall.

As far as multipitch, I just leave a big loop(unless there is a ledge) and don't worry about any fancy belaying technique beyond catching them if they fall.


mewalrus


Jul 23, 2003, 2:02 AM
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In reply to:
Right. But as was already pointed out, this is only if the grigri is directly hooked to the anchor. If you are belaying with the grigri attached to your waist, you can't generate more force than body weight (ok, as somebody pointed out--if you are being accelerated, you can produce more force than your weight, but it won't be much). This means if you catch a fall with a grigri, you might get lifted off the ground but you won't be applying much more than a few hundred pounds (unless or until you come tight on your anchor or you get lifted all the way up to the first bolt).


I am pretty sure you are dead wrong on that one. Force and weight are two very different concepts.


jt512


Jul 23, 2003, 2:10 AM
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In reply to:
Jay,
I wouldn't let someone belay me using that technique and if I saw someone keeping their hand in front of the device, I wouldn't fall.

That's the standard way to belay a leader with an ATC, Dan. Only gumbies keep the rope locked off all the time, unless their partner is moving at a snail's pace. It's the rope-behind-the-butt-all-the-time belayers that you should worry about. They'll short rope you on every move.

This is how it should be done (cute tilting of head is optional):
http://www.rockclimbing.com/...mp.cgi?Detailed=3810

From this position, she can lock off or feed rope instantly. To dynamically belay, the hands should be kept further from the ATC, but the angle between the ropes is correct.

-Jay


elrojobdugs


Jul 23, 2003, 4:05 AM
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does anyone here use both hands on the slack part... or seen anyone doing so... i recently was at a gym and two guys were doing it... whats up with that... theyd pull straight up with the slack with both hands and go into brake position...???


traddad


Jul 23, 2003, 1:14 PM
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Jumpin' Jay,
She can belay me any time. You and your double back flip with a full twist belay method on the other hand... :twisted:
Let me guess, you never get more than 80 feet off the ground, or more than 20 feet fom the bumper of your car.... :P


sticky_fingers


Jul 23, 2003, 1:52 PM
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In reply to:
Have you ever tried to do a squeeze chimney with a gri gri on your harness?

To be honest, no, I've never done a tight chimney. However, from all the videos and pics I've seen of people climbing (seconding?) tight chimneys, I'd imagine I'd put as much "big" gear on the outside of my harness as possible, including fatty cams, bros and gri-gri.


traddad


Jul 23, 2003, 2:05 PM
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Squeeze chimney? You're going to worry about a gri gri when your humping a rack of #5 Camelots, big bros and Valley Giants?
(There, I mentioned Valley Giants....do I get a discount?)


redpoint73


Jul 23, 2003, 2:08 PM
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In reply to:
does anyone here use both hands on the slack part... or seen anyone doing so... i recently was at a gym and two guys were doing it... whats up with that... theyd pull straight up with the slack with both hands and go into brake position...???

Yeah, I've seen that at the gym as well! And I seem to be noticing it more recently. It seems inefficient if you need to take up slack quickly, but I don't belay that way, so I can't really say. I have heard some of those belayers state "that was how they were taught".

Those folks seem less experienced. They will likely find that once they get outside and need to belay a leader, that they will have to totally relearn how to belay. Now learning how to lead belay takes some practice regardless of your TR technique, since you are mostly throwing out slack instead of taking it up. But these guys will have to completely rethink their hand position and movement.


markc


Jul 23, 2003, 2:44 PM
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Too heavy and bulky??????
gimme a break
i just went on REI's home page where they list a BD ATC (not XP) as weighing 49 grams and a gri-gri weighing 225 grams

Bottom line: A gri-gri is only 176 grams heavier than an ATC.

[Snip body weight analysis.] If an additional 0.25% of your body weight is too heavy for you to carry, get off the rock. Besides, YOU'RE BELAYING not leading. If the only reason you can't second a climb is because you have to schelp a gri-gri, then you have other problems.

Bulky? what and carrying a rull rack is like a second skin? remember you're belaying. when you climb (if you follow) you begin with NO gear and pick it up as you go. Most likely you'll end up with less than the full rack because the leader probably carried more than he/she needed to.

I'm not trying to sway anybody's opinion, I'm just trying to thow out the arguments that's it's too heavy and bulky.

You make multiple references to seconding. When I climb, I'm either switching leads or taking them all. What do you suggest I do with my gri-gri whilst leading? If I'm climbing with the thing, I might as well belay my second with it. Besides, it's because of the bulk of the rack that I don't want that much excess baggage. I already carry more pro than I need, why bring two belay devices (one of which I can't rappel with)? I'm not an ounce-shaver, but my "might as well" attitude has limits.

If I'm on a multi-pitch route, I'm going to need another device (or gri-gri shenanigans). A gri-gri AND another device will be heavier and bulkier than one. You might not mind it, but that's still the way it is. Carry what you will, but don't ask me to lug your gri-gri if the next pitch is looking a little heady.

mark


sticky_fingers


Jul 23, 2003, 3:32 PM
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markc: Point taken, but I was presuming that the leader would carry up a lighter device (ATC, knot, etc) to belay with, while the second could easily follow with a gri-gri, and not be held back by its weight or size. Hell, the second could even carry up an ATC. :shock: Maybe it's not the most convienent, but I'd bet dollars to doughnuts (haha my dad's expression) that if you were leading and something konked me on the head, you'd wished I had my hands on a gri-gri rather than an ATC.

Look, the original post was about wether or not belaying on trad with a gri-gri was considered dangerous. Now it's gotten into a convenience thread. I can't imagine anybody reading/posting on rc.com in a more inconveinent position than climbing a possible 15a without part of a finger (i know, i know...sport/trad), so until somebody gets shut down by gear weight/size, i think this is a silly discussion. I don't think anybody can make a case where the increase in safety afforded by a properly loaded gri-gri is not worth it's wight/size.


markc


Jul 23, 2003, 4:02 PM
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Well, Mr. Fingers, we'll have to agree to disagree on the gri-gri issue. I'm the first to admit it's not my preferred belay device.

Happy climbing,

mark


alpnclmbr1


Jul 23, 2003, 4:08 PM
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Sticky-fingers
If your in a real squeeze chimney you want to hang "all" your gear on a long sling hanging from your belay loop.(lead or second)

As far as the rockfall thing, if you knock your belayer out with a rock you deserve to get hurt as far as I am concerned. A helmet and a gri gri does very little to help things, your much better off not knocking rocks down in the first place. Rock fall usually kills the belayer not the leader, and if a leader thinks a belayer using a gri gri makes him safer I wouldn't want to belay him.


tenn_dawg


Jul 23, 2003, 4:17 PM
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In reply to:
Chris Harmston wrote
In reply to:
The MH is one of the most static belays available. This can be very
dangerous when you must rely on the dynamic belay. In trad and ice
climbing the MH can be very dangerous because it will increase the loads
felt by the top anchor.

Different post
(snip)
Here is another example of some "uncontrolled" testing I have been
involved with.

Last winter Craig Luebben and I conducted some drop tests on ice. Craig published an article in Climbing Mag on some of these results and results of his static tests. I have also written an article on static tests I have conducted in the lab (email me if anyone wants a copy). Anyway, we set up our tests under the bridge in Ouray. This was in pretty bad ice actually and for the most part the gear did not hold. Our setup was with a static belay, a new 10.5 mm BD rope, fall factors in the 1.5 to 1.8 range, and 185 pounds of steel. With this setup the only thing that actually held was a 10 cm screw. Everything else ripped out OR carabiners broke! I attribute this to the bad ice and that the 10 cm screw that held was probably in the only good ice we found.

We decided to conduct a series of tests where we used the same section of rope over again. The first three tests the gear ripped out. On the fourth drop we about keeled over in disbelief. We had a Snarg as the test piece connected to the rope with a draw with BD QS2 biners. A few feet below this was two equalized screws (BD and a Grivel). They were equalized with a single 24" sling and a locked Big Easy was connected to the rope. The biner on the snarg broke, the hanger on the Grivel screw sheared along its long bend, then the big easy locked biner broke! This is three pieces of hardware that broke on one fall. Now, I am assuming that these were not defective products (a solid assumption based on my knowledge of all the gear and the systems to produce it, and a review of the fracture surfaces of the parts we actually recovered). This means that the forces generated were well in excess of 5000 pounds (multiple times!). Now the tricky part. Conducting a static test on a new rope with the same diameter with the same type of knots caused the rope to break in the 3500 pound
range. I don't know why the gear broke and why the rope did not. There was about one hour between drops so the rope had some reasonable time to recover.

Now the good news. When we placed an ATC in the system (i.e. some dynamic aspects) every test we conducted held except for a couple of tests with Spectres.

What does this mean? Dynamic belays are your friend! Climbers have known this for about a century now. Many climbers today do not understand this very well. This is why I am relating these types of info to this news group. I am purposely trying to get this group to discuss this stuff in detail and learn something from it.
(snip)

This "testing" proves nothing. They were not controlled circumstances, and they don't even describe their setup.

To the best I can understand, they were belaying directly off of an anchor, and dropping a weight from a lower height onto a rope to produce aprox. factor 1.8 falls

This has no relevance to forces felt on a lead placement durring a regular climbing fall.

Beyond that, the testing is so unstandardized that I can't believe that it was published in any context.

All it proves is that high factor falls on bad anchors cause failure. Who knew?

Travis


alpnclmbr1


Jul 23, 2003, 4:29 PM
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In reply to:
That's the standard way to belay a leader with an ATC, Dan. Only gumbies keep the rope locked off all the time, unless their partner is moving at a snail's pace. It's the rope-behind-the-butt-all-the-time belayers that you should worry about. They'll short rope you on every move.

This is how it should be done (cute tilting of head is optional):
http://www.rockclimbing.com/...mp.cgi?Detailed=3810

From this position, she can lock off or feed rope instantly. To dynamically belay, the hands should be kept further from the ATC, but the angle between the ropes is correct.

-Jay

I guess I am a gumbie because, I keep the device locked off whenever I am not looking at the climber or feeding a clip. I actually lock the device against the biner, not put my hand behind my butt, and I don't short people

As far as the posed picture of your hottie belayer,
She is belaying a toprope with tension from the looks of it. Her hands are in a bad position, unless she is shuffling a toprope belay. She it to far from the rock, she has a bunch of junk under her feet that she could trip on.
Not a very good example of lead belaying technique.


sticky_fingers


Jul 23, 2003, 4:36 PM
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In reply to:
Sticky-fingers
If your in a real squeeze chimney you want to hang "all" your gear on a long sling hanging from your belay loop.(lead or second)

that's pretty much how i do it. i was just being brief earlier describing how to rack stuff going up a chimney...outside.

In reply to:
....your much better off not knocking rocks down in the first place.

obviously, but you don't always know what's ahead or if the rock will hold. Look what happened on the Totem? I'm sure no one intended for that to happen....

In reply to:
Rock fall usually kills the belayer not the leader, and if a leader thinks a belayer using a gri gri makes him safer I wouldn't want to belay him.

yes....rocks do usually fall towards earth. I haven't seen a whole lot of ripped out flakes turning around and attacking the leader. at least we agree that gravity hates the belayer

seriously though, I'm gonna assume you drive with seat belts (same principle). the reason you do is in the unlikely event you're going too fast to stop your motion by yourself, a seat belt locks up for you. In the unlikely event my belayer can not belay me, i hope my life won't also be in jepordy.


alpnclmbr1


Jul 23, 2003, 4:41 PM
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Tenn-dawg

In reply to:
We had a Snarg as the test piece connected to the rope with a draw with BD QS2 biners. A few feet below this was two equalized screws (BD and a Grivel). They were equalized with a single 24" sling and a locked Big Easy was connected to the rope. The biner on the snarg broke, the hanger on the Grivel screw sheared along its long bend, then the big easy locked biner broke! This is three pieces of hardware that broke on one fall.

This is a lead placement configuration. And the anchor didn't fail, the gear itself broke.

Agreed that this isn't an ideal test, but Harmstom is one of the best authorities on rock gear that I have heard of and he contends that a static belay device significanly increases the forces on lead placements.


tenn_dawg


Jul 23, 2003, 5:25 PM
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In reply to:
Tenn-dawg

In reply to:
We had a Snarg as the test piece connected to the rope with a draw with BD QS2 biners. A few feet below this was two equalized screws (BD and a Grivel). They were equalized with a single 24" sling and a locked Big Easy was connected to the rope. The biner on the snarg broke, the hanger on the Grivel screw sheared along its long bend, then the big easy locked biner broke! This is three pieces of hardware that broke on one fall.

This is a lead placement configuration. And the anchor didn't fail, the gear itself broke.

Agreed that this isn't an ideal test, but Harmstom is one of the best authorities on rock gear that I have heard of and he contends that a static belay device significanly increases the forces on lead placements.

I agree, it is certain that using a static belay device will increase forces on a lead placement. The question is to the degree of increase (most preferably measured in percent) in a variety of similar situations.

This test would be so easy to do: Simply aquire 3 or 4 ropes for test medium, Set a high anchor with a load measuring device, and lob off some weights. I would preferably use a Human belayer, holding the device in the full locked off position, standing straight up on his feet, and not jumping.

Alternate ropes so the dynamic properties have time to regenerate, and go through a sample set, measuring the loads using a constant weight, drop distance. Switch belay devices, and measure again.

A little math, and you have a definate percentage difference in load felt. A little more time and math, and you could get the standard deviation of both curves and figure out if the difference is statistically significant.

No sweat.

A day would be plenty of time, and If I had the resources avaliable, I would do it on my own. Sadly, I'm absolutely broke, and can't dedicate any funds to this.

Someday though...

Travis


jt512


Jul 23, 2003, 6:41 PM
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In reply to:
As far as the posed picture of your hottie belayer,
She is belaying a toprope with tension from the looks of it. Her hands are in a bad position, unless she is shuffling a toprope belay. She it to far from the rock, she has a bunch of junk under her feet that she could trip on.
Not a very good example of lead belaying technique.

The picture was not posed, she is belaying a leader, and there is no tension in the rope. As I already stated, I posted the pic to demonstrate what I consider a good angle at which to hold the ropes when belaying a fast climber, not the optimal footwear.

This is the approximate angle at which most experienced sport climbers hold the ropes. Look at pictures of professional sport climbers in magazines. The belayer doesn't have the belay device locked off while the climber is moving. He has the rope in a neutral position -- 45 to 90 degrees apart -- from which he can quickly take in or let out slack. There is no reason to lock off the belay device every time you let out slack. When the leader falls, then you lock off. You do not lose control of the belay, even if caught off guard, in part, because with the ropes at 45 - 90 degrees from each other, the device still provides friction. I have caught innumerable falls this way, as have innumerable other belayers. If you can avoid short roping the climber without leaving too much slack in the rope and locking the device off constantly, then the only disadvantage you have is that you can't let rope run through the device to dynamically belay -- a minimal disadvantage on most sport climbs because you have the option of jumping, which is what most of us do, anyway.

-Jay


alpnclmbr1


Jul 23, 2003, 7:02 PM
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Jay,
Agreed that the angle between her hands looks fine.

My comment about the hand in front of the device was directed at people who keep both strands closer to parallel, not 45 to 90.

btw, when I "lock off" the device I do it with the non-break hand, ie snug it against the biner. This helps insure that I don't get caught off guard. A confusing different application of the word, but still the best I can think of. A good example of how the written word doesn't cover all the bases.

For myself on lead in particular, the rope in the pic would be tension.


jt512


Jul 23, 2003, 7:09 PM
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In reply to:
This test would be so easy to do: Simply aquire 3 or 4 ropes for test medium, Set a high anchor with a load measuring device, and lob off some weights. I would preferably use a Human belayer, holding the device in the full locked off position, standing straight up on his feet, and not jumping.

Alternate ropes so the dynamic properties have time to regenerate, and go through a sample set, measuring the loads using a constant weight, drop distance. Switch belay devices, and measure again.
Travis

I'm pretty sure such tests have been done; otherwise, where would the specific numbers quoted for the braking forces of various devices have come from? Once again, Clyde Soles would probably know. He wrote an article for R and I in which he quoted these figures.

As far as the specifics of the test, it would be a little less straightforward than you describe. Conventional belay devices act as grip strength magnifiers; their braking force is thus a function of how strong the belayer is. Also the belayer's body size and position will affect the impact forces. Rope diameter and, of course, construction, also affect impact forces. For purposes of compaisons among belay devices these factors can be largely controlled by using the same belayer and similar ropes for each belay device, at the expense of generalizability. It would be unwise to use the same rope for more than one test, though, even allowing for recovery time, because it cannot be reasonably assumed that the rope would fully recover.

-Jay


alpnclmbr1


Jul 23, 2003, 7:44 PM
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In reply to:
This test would be so easy to do: Simply aquire 3 or 4 ropes for test medium, Set a high anchor with a load measuring device, and lob off some weights. I would preferably use a Human belayer, holding the device in the full locked off position, standing straight up on his feet, and not jumping.

Alternate ropes so the dynamic properties have time to regenerate, and go through a sample set, measuring the loads using a constant weight, drop distance. Switch belay devices, and measure again.

Travis

I found a reference to a test that rei did and they used a clutch mechanism for the belayers hand set at 50lbs.(googled rec.climbing)

On the clarification side, I don't think using a gri gri would be unsafe. But it probably is less ideal then an atc where impact forces are concerned.


alpnclmbr1


Jul 23, 2003, 8:13 PM
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Full text at
http://www.somat.com/applications/articles/rei.htm


(snip)
Because REI wanted to evaluate the performance of different belaying devices to establish which ones were best for various climbing situations, they needed real-world load data. They designed a series of tests that would measure the performance of the belaying devices by quantifying two factors. One was the peak load experienced by the protection. The other was average load which tells how soft or how firm the catch is.

The test is performed by dropping a steel plate from a modified UIAA drop tower which is two stories tall. The letters UIAA stand for the French alpine organization which standardized the drop test. To simulate the climber in the test, the engineers use an 80 kg (176 pound) steel plate. This plate has a Teflon block at each corner and when it is dropped to simulate a fall, it slides down the aluminum rails mounted into the timbers which form the tower. The rope is attached to the plate and then goes through the carabiner and the belay device. From there it runs through the brake hand and then through two spring loaded plates that provide friction on the rope that simulates the belayers' grip hand. This plate holds the rope with what the engineers determined was an average grip force--25 pounds. One load cell is attached to the protection and the other to the friction device that represents the belayer. They initially tried to attach a third load cell to the plate representing the climber but it moved so much during the drop that it broke the wires. Since the Model 2100 permits on-line data analysis, the load on the climber is derived by combining the data from the other two measurement channels.
(snip)
The test findings confirmed what experienced climbers had suspected but never had actual load values to prove. For example, the cam lock static belay device put the greatest load on the protection--2215 pounds. The load on the belayer in this test was 839 pounds and the load on the climber was 1382 pounds. Another type of belay device called the Trango Pyramid was expected to have a light catch. It did, expelling nearly 30 inches of a 10.5 mm rope. The maximum load on the protection with this device was 927 pounds. The loads on the belayer and climber were 265 and 662, respectively. One of firmest catches from a dynamic belaying device came from the HB Bigger Brake which put a load of 392 pounds on the belayer, 835 pounds on the climber, and 1227 on the protection.
(snip)

I am back to thinking grigri's are bad for trad.


ambler


Jul 23, 2003, 9:17 PM
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That's quite a difference, around double the force on the protection from a static Gri-gri belay (or Muntner?). Reinforces my own prejudice that for trad free climbs, at least, ATCs and the like are the best way to go.

The other striking thing in this thread is the note about carabiners breaking, but not the rope which was theoretically weaker. There has been much discussion on these forums about the strength of various knots in rope and webbing, but I can't offhand recall reports of accidents where ropes or slings broke (cut or came untied, yes). On the other hand I've broken two carabiners in falls myself, and heard of many others. It seems like the metal gear in the system often might be more fragile, in practice, than its rated strength would suggest.

Reinforces the advice I think Brutus has trademarked, that falling can be a Big Deal.


tenn_dawg


Jul 24, 2003, 1:04 AM
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In reply to:
I'm pretty sure such tests have been done; otherwise, where would the specific numbers quoted for the braking forces of various devices have come from?

That test was done by hooking a puller to the rope and pulling directly against the device, and observing the load at which the rope began to slip.

It is related, but still not a good indicator of the force felt on the lead piece for reasons I've stated above, including the duration of >500lbs force exerted at the belay device, and the resulting distance of rope slip.

The two are related, but I've never seen how much this really affects the load force, and duration felt at the lead placement. And this is really the key issue here. Not the force at which the device allows the rope to begin slipping.

Travis


tenn_dawg


Jul 24, 2003, 1:09 AM
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Dan,

That study is good stuff. Finally, an experiment that measures forces at the lead placement. I haven't got to read the full text yet, (economics test tomorrow) but I'll get on it as soon as I get a chance.

Thanks for digging up a good study!

Travis


alpnclmbr1


Jul 24, 2003, 4:03 AM
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Tenn-dawg,
It is pretty good stuff. Kind of funny that the testing machine company was the one to post it.
Good luck on your test.
d.


traddad


Jul 24, 2003, 2:58 PM
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One improvement I'd like to see on that test is to simulate the belayer. I didn't read the whole test (I'm at work) but I suspect the 'biner hooked into the belay device is attached to a post or some other completely static set up. Like I said in an earlier post, the acceleration of the belayer, friction in the harness, compression of the kidneys and nuts (assuming a male climber) :D may take at least some of the edge off the impact force. What I'd REALLY like to see is a "Real World" test scenario where a trained belayer catches a large number of falls (say, 50+ for each device) and the impact force is averaged over the large N for each device. While the error bars would probably be huge, statistical methods could be used to test if the mean was representative.
I'm an ecologist working in the field of ecotoxicology. I hate it when people try to extrapolate from laboratory derived data to characterize the real world. The complexities involved in real world situations often (read: most of the time) drown out what ever variable was being tested for in the lab. There is a LOT of noise out there.


tenn_dawg


Jul 24, 2003, 3:07 PM
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Very good points, I still can't read the entire test, but I think the resuts may be slightly suspect. When I get a chance I"ll really pool over the results, and methods and figure out exactly what they've shown.

You can only take experiments results so far. It is still nessessary to question results and formulate your own conclusions.

Travis


sspssp


Jul 24, 2003, 3:24 PM
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[quote=]The test findings confirmed what experienced climbers had suspected but never had actual load values to prove. For example, the cam lock static belay device put the greatest load on the protection--2215 pounds. The load on the belayer in this test was 839 pounds and the load on the climber was 1382 pounds. Another type of belay device called the Trango Pyramid was expected to have a light catch. It did, expelling nearly 30 inches of a 10.5 mm rope.

I am back to thinking grigri's are bad for trad.
First, as the other poster pointed out, you aren't going to get 839 pounds of force on the belayer, unless the belayer is anchored without slack, which most are not. Instead, you are going to pick the belayer up off the ground and get at most a few hundred.

Second, this is a pretty extreme fall scenerio. Not one that comes up that much.

Third, the ATC type device let 30 inches of rope go through the device while the brake force was being applied. So how many of you wear gloves when belaying? What type of rope burn do you think you are going to get after 2 and half feet of rope slice through your hand? Now that your belayer's brake hand is a raw, bloody mess, are they going to be able to keep the rope locked off? Maybe, but there are up sides to the grigri.


uncertaintyprinciple


Jul 24, 2003, 3:25 PM
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delete


jt512


Jul 24, 2003, 4:23 PM
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In reply to:
That's quite a difference, around double the force on the protection from a static Gri-gri belay (or Muntner?). Reinforces my own prejudice that for trad free climbs, at least, ATCs and the like are the best way to go.

The other striking thing in this thread is the note about carabiners breaking, but not the rope which was theoretically weaker. There has been much discussion on these forums about the strength of various knots in rope and webbing, but I can't offhand recall reports of accidents where ropes or slings broke (cut or came untied, yes). On the other hand I've broken two carabiners in falls myself, and heard of many others. It seems like the metal gear in the system often might be more fragile, in practice, than its rated strength would suggest.

No, it's not that. When biners break it is because they have been loaded improperly, most often (I suspect) with the gate open. The worst CEN biner will hold the worst-case lead fall if loaded along its major axis with its gate closed. On the other hand, open-gate strengths of biners range from 7 to 10 kN (1600 to 2300 lbf). Ovals, IIRC, are permitted to be even weaker. One glance at the paper posted by Alpnclmbr1 should convince you to invest the extra $3/biner for the better, higher open-gate strength biners, such as Petzl Spirits or DMM Wirelocks.

-Jay


jt512


Jul 24, 2003, 4:37 PM
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In reply to:
One improvement I'd like to see on that test is to simulate the belayer. I didn't read the whole test (I'm at work) but I suspect the 'biner hooked into the belay device is attached to a post or some other completely static set up. Like I said in an earlier post, the acceleration of the belayer, friction in the harness, compression of the kidneys and nuts (assuming a male climber) :D may take at least some of the edge off the impact force.

While those factors reduce the impact forces of actual falls, the test results are not necessarily unrealistically high. In most real-world falls the impact forces on the anchor and the falling climber are increased by frictional forces between the rope and intermediate protection. These not only act as additional braking forces, but they also reduce the amount rope stretch, effectively increasing the fall factor.

Evidence that real-world impact forces are at least on the order of those reported in the test come from reports of biners breaking in falls. Presumably, these biners are loaded improperly, usually gate open, and so will fail at loads ranging from 1600 to 2300 lbf. Biners have been failing prior to the invention of the grigri, which suggests that real-world impact forces can exceed those reported in the test.

-Jay


alpnclmbr1


Jul 24, 2003, 5:04 PM
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Thanks Jay,

For one, the harness and knots do not absorb a lot of energy in the system according to the authorities I have read. (clyde soles among others) As far as lifting the belayer, that would happen with a grigri or atc.

For two, these are worst case falls, which are the ones you are most worried about. The fact that they do not happen very often is irrelevant, and you can extrapolate from the data offered.

For three, when speaking in terms of fall factor calculations more commonly found in actual climbing, the forces are actually worse then the numbers would suggest. This is due to friction in the system from the rock, biners etc. that limit the absorption ability of the rope by focusing the force on the section of rope between you and the last piece. (thus the wear pattern observed on sport climbing ropes)

For four, I notice a pattern of analyzing the data to suit your own preconceived notions. The test was set up by trained engineers who took as many worthwhile factors into consideration as they could. (and from inferences in the article they probably tested the issues your speaking of)

It is a fact that in a close to factor 2 fall scenario a grigri could contribute to blowing out your anchor system. And none of your comments on how the test could be improved would effect the test results in this regard.


papounet


Jul 24, 2003, 5:24 PM
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dear

There is nothing better than data recorded in scientific experiment to contradict "beliefs".
If you think that a belay system anchorer to a live body is always better than a device anchored to the rock, read on.

Real test data available from http://journal.uiaa.ch/archive.asp
the file you want is http://journal.uiaa.ch/download/20003.pdf

...
During 1998 and 1999, a few hundred
tests were conducted on rock and
on the Tower, comparing belay devices
and belay systems, use of single rope
and twin ropes, rock-belay and bodybelay.
here in order to stimulate discussion.
...
During 1999, two experimental sessions
were held at Passo Rolle (Dolomites
region). A rock face was
equipped with runners up to a height of
12 meters (Fig. 1). An 80-kg steel mass
was raised 2 m from the last runner
above an overhang, thus providing a
4-m free fall.
Peak forces and, more recently, full
plots of the forces occurring in two or
three points of the belay chain were recorded.
In the two sessions, about 100
cases were studied.
...

the part I prefer
========
The inertia of the belayers body can lead to a
higher peak load on the last runner,
compared to the load caused by the regular slippage of the
rope in a device attached to the stance. The role of the inertia is
tricky; e. g. it is not always true that the load on the
last runner is lower when the friction along the
runners chain is lower: the pull on the belayers
body is stronger in this case, so that his inertia can be the prevailing
effect in determining the forces on the last runner. Depending
on the circumstances, an increase in the belayers mass
can lead to a reduction or an increase of the load on the last runner
or on the stance.


micahmcguire


Jul 24, 2003, 8:21 PM
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i don't like to use my grigri except for belaying my follower after I have led up a climb. Its a very convienent bit of gear to have, especially when room on the belay platform is limited, if you have to be periodically fiddling with things with one hand, etc. Aside from that, its bulky, its big, and people don't seem to know how to use it properly. My two cents boils down to this: if someone gives you a grigri for your birthday or what-have-you, yippee. If not, its way too pricey and bluky to be worth spending $$$ on. Get a cheap ATC, its smaller, lighter, and does the same job.


mewalrus


Jul 24, 2003, 10:45 PM
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In reply to:

First, as the other poster pointed out, you aren't going to get 839 pounds of force on the belayer, unless the belayer is anchored without slack, which most are not. Instead, you are going to pick the belayer up off the ground and get at most a few hundred.




Please explain how a 176 pound weight generates over 2,000 pounds of force at the protection? how?
I believe you could easily generate 839 pounds of force on a 150lb belayer. Plus the force at the belayer is not the significant number anyways, its the force on the protection thats significant.

pounds force=(32.174 * pounds mass * ft)/ seconds^2

The belayers weight is not very significant. The TIME scale is what very signifcant. You see that time squared. If you double the time it takes to stop the fall the force goes down by a factor of 4. If you triple the time the force goes down by a factor of 9!!!

Anything you can do to lengthen the time will have the greatest reduction in force. This is how dynamic ropes work, you fall further but the force is way less because they stretch out the time factor.


traddad


Jul 24, 2003, 10:47 PM
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Papounet,
What I think they are actually saying is that friction caused by the rope running through the runners actually decreased the load placed on the top runner. I whole heartedly agree with this. Another reason to sew up a pitch like Betsy Ross :D. It does not mean, however, that accelerating the belayer is a bad thing. It just means that the runners act as "shock absorbers" if you will isolating the belayer from the falling object. Think of it as the difference between having someone fall with a lot of slack on a top rope vs falling with the same slack with the added drag of the runners between the belayer and the climber.
The less rope drag you have the more force you'll put on your top runner?!


alpnclmbr1


Jul 24, 2003, 11:53 PM
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In reply to:
Papounet,
What I think they are actually saying is that friction caused by the rope running through the runners actually decreased the load placed on the top runner. I whole heartedly agree with this.

This is completely wrong, the friction on the lower pieces increases the impact forces on the last piece and the falling climber by making the rope between the climber and the last piece of gear absorb more of the force, not less.

To put this another way, If you only had one piece in, the rope between the top piece and the belayer would all stretch equally. Each point of friction prevents that force from spreading over the whole length of rope equally, leading to a higher impact force due to making less use of the ropes ability to absorb energy. This is why real world fall forces are worse then the numbers only calculations.


micahmcguire


Jul 25, 2003, 1:23 AM
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agrees (finally) with mewalrus. its decelaration over time that prevents damage to you, to your anchor, to everything. the more time it takes to slow down, the less of a shock it will be on the anchor, the rope, the climber, their poor crotch, etc. This is why airbags are in cars. It takes longer to deccelarate through an airbag than into a steering wheel, and certainly does less damage to the occupant.

also I should point out that alpineclimber1 (SP) is quite correct. very correct. do not question.


traddad


Jul 25, 2003, 1:41 AM
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Hmm...I see your point. Having less friction in the system will let the rope do the work it's designed for. Makes sense. I retract my previous statement. Guess I was thinking static rope thoughts.

Shall I run it out, sir?


alpnclmbr1


Jul 25, 2003, 1:48 AM
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In reply to:
also I should point out that alpineclimber1 (SP) is quite correct. very correct. do not question.

Actually, I wish you would challenge my assumptions, if I am wrong, I want to know it. The whole point of spending time on this site is to learn a thing or two.


micahmcguire


Jul 25, 2003, 2:01 AM
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ok, but I won't, because you are right. obviously a twenty foot chunk of rope won't stretch as much as a 100 foot chunk of rope of the same type. elemetary my dear alpnclmbr1. or were you talking to everyone else?


norushnomore


Jul 25, 2003, 9:55 AM
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Look into using TRE.

Will lockup like gri-gri but will let rope slip like an ATC.

Best of both and you double-rope rappel with it (with no need for the back up either)

G


papounet


Jul 25, 2003, 1:10 PM
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My previous post was a bit rushed and I may have cut&pasted a passage which wasn't the most relevant.

I would encourage you to read carefully the UIAA document.

you'll find such gems as :
" At the beginning, we had to devote most of our efforts to convincing the
climbers that in the large majority of real cases the friction between rope and
rock is determinant in holding the falling climber; consequently, testing belay
at the tower was essential to appreciate what can really happen in a bad
(though unlikely) case, i. e. when there is no friction. "

or
"In the body-belay process the first phase is inertial, ...".

Doing some more searches I found the one of most complete scientific document
yet from the Central Commission for Equipment and Techniques of the Italian Alpine Club

http://www.caimateriali.org/Articoli/TecnicheDiAss_/tecnichediass_.html

http://www.caimateriali.org/Articoli/articoli.html

But as my italian is not up to par, I'll pass on this article


papounet


Jul 25, 2003, 1:47 PM
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Google is magnificent: http://www.leeds.ac.uk/sports_science/abstracts/climb99/wnachbauer1.htm

1st INTERNATIONAL CONFERENCE ON SCIENCE AND TECHNOLOGY IN CLIMBING AND MOUNTAINEERING.
7th - 9th April 1999 University of Leeds, UK.

--------------------------------------------------------------------------------

Forces on the Falling Climber Depending on Different Belaying Techniques

R Messner, G Meraner, T Schliernzauer, B Knuenz, W Nachbauer

Department of Sport Science, University of Innsbruck, Austria

Traumatic and overuse injuries to the spine were observed with climbers falling in the rope. The purpose of this study was to investigate the influence of different belaying behaviours and devices on the force measured between rope and harness of a falling climber.

One subject (m = 70 kg) performed standardised falls with a fall factor of z = 0.375. The following situations were tested: static belay at a bolt (1 trail), static belay at the body using a Grigri (1 trial), belay with backward movement of the belayer using a Grigri (1 trial), dynamic belay by a jump using a Grigri (10 trials), dynamic belay using a figure of eight (10 trials), dynamic belay using a HMS-karabiner (10 trials). The force between rope and seat harness was measured by a strain gauge. From the recorded force curves the peak force was determined and compared for the different situations.

For the single static belay at a bolt an about two times higher peak force (4006 N) than the mean peak force of the 10 dynamic trials using the Grigri occurred (2083 N, s = 175.7 N). The differences between different belaying behaviours using the Grigri were as follows: in case of a backward movement of the belayer the peak force was 3887 N which is close to the static trial, in case of no movement of the belayer the peak force was 3267 N, and with a jump of the belayer in rope direction it was 2083 N. The comparison of the belaying devices showed mean peak forces of 2368 N (s = 172.5 N) for the HMS-karabiner, 2197 N (s = 234.0 N) for the figure of eight, and 2083 N (s = 175.7 N) for the Grigri. The difference between HMS-karabiner and Grigri is statistically significant.
=====

My take:
doing a jump with a Grigri, despite not letting go of the rope, allow a smoother fall arrest, with less force on top piece and on climber arrested.
If the fall was uncertain, one step forward would be quite beneficial
if the fall was clearly dangerous, extreme measure such as running gbackward to limit fall length could be adequate despite harder fall arrest.


===
The post to end all post ????, not yet


tradklime


Jul 25, 2003, 5:24 PM
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My take:
doing a jump with a Grigri, despite not letting go of the rope, allow a smoother fall arrest, with less force on top piece and on climber arrested.

Now apply that to the context of this thread, trad climbing. A step further, to a hanging John Long style belay. How much jumping are you going to do? I think the best context to look at it is that the belayer will be somewhat static in position. Having a device that allows some rope slip will provide the next best thing to a jump with a static device.


micahmcguire


Jul 25, 2003, 5:28 PM
Post #98 of 118 (7325 views)
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very much agreed


brutusofwyde


Jul 25, 2003, 9:13 PM
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Too heavy and bulky??????
gimme a break
i just went on REI's home page where they list a BD ATC (not XP) as weighing
49 grams
and a gri-gri weighing
225 grams

Bottom line: A gri-gri is only 176 grams heavier than an ATC.

Another way of looking at this is the grigri weighs more than FOUR TIMES what an ATC weighs, and is not an effective rappel device. And the ATC is not the lightest belay device on the market.

I try to pare every gram, and maximize utility of what I carry.

60 carabiners @ 65 grams apiece vs 60 Neutrinos at 37 grams each.
Titanium cams and DMM cams vs. Camalots can make pounds of difference in a double set of cams.

8.1mm double ropes where full rope rappels are necessary.

a stove that weighs 64 grams.

In reply to:
I'm not trying to sway anybody's opinion, I'm just trying to thow out the arguments that's it's too heavy and bulky.

I'm not convinced, and I own two Grigris. Hard backcountry climbs with long approaches require some significant weight management.

Brutus


jt512


Jul 25, 2003, 9:19 PM
Post #100 of 118 (7325 views)
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Re: trad... big no no [In reply to]
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In reply to:
In reply to:
Too heavy and bulky??????
gimme a break
i just went on REI's home page where they list a BD ATC (not XP) as weighing
49 grams
and a gri-gri weighing
225 grams

Bottom line: A gri-gri is only 176 grams heavier than an ATC.

Another way of looking at this is the grigri weighs more than FOUR TIMES what an ATC weighs, and is not an effective rappel device. And the ATC is not the lightest belay device on the market.

I try to pare every gram, and maximize utility of what I carry.

60 carabiners @ 65 grams apiece vs 60 Neutrinos at 37 grams each.
Titanium cams and DMM cams vs. Camalots can make pounds of difference in a double set of cams.

8.1mm double ropes where full rope rappels are necessary.

a stove that weighs 64 grams.

Brutus, tell me you had to look up those weights, and that you don't have them all memorized.

-Jay


brutusofwyde


Jul 25, 2003, 9:24 PM
Post #101 of 118 (7539 views)
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Squeeze chimney? You're going to worry about a gri gri when your humping a rack of #5 Camelots, big bros and Valley Giants?
(There, I mentioned Valley Giants....do I get a discount?)

I used Valley Giants, big bros, and #5 camalots three weeks ago on the FA of Wagon Train in the Sonora Pass area. I don't carry any of that stuff on the harness in squeeze chimneys. The second sends up what I need on the tag line. So, no, I'm not carrying a grigri, or any of that pro, through the squeeze chimney.

But the grigri still stayed in the truck... humping all those big cams to the base of the climb was quite enough work, thank you, and I still needed my Jaws (which I had with me) for the double rope rap.

Brutus


papounet


Jul 25, 2003, 10:02 PM
Post #102 of 118 (7539 views)
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In reply to:
Now apply that to the context of this thread, trad climbing. A step further, to a hanging John Long style belay. How much jumping are you going to do? I think the best context to look at it is that the belayer will be somewhat static in position. Having a device that allows some rope slip will provide the next best thing to a jump with a static device.

Point taken.

In fact whenever I hear trad, I think of mountainous, multi-pitch trad routes => which in my view means double rope (because of possible rappel/bail-out). for which of course the Grigri i snot apropriate


brutusofwyde


Jul 26, 2003, 12:54 AM
Post #103 of 118 (7539 views)
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In reply to:
Brutus, tell me you had to look up those weights, and that you don't have them all memorized.

-Jay

Uhhh... :oops:
I did put them out there from memory.
But I think the Neutrinos are actually only 36 grams... its Dovals that are 37. And what oval weighs what, well, it depends on the brand.

I only had the stove and Neutrino weights memorized because I spent a lot of time researching before replacing my entire set of carabiners with Neutrinos, and the stove because of similar research and special ordering of the titaniom Snowpeak.

I confess I don't have all the cam weights memorized, but on the average I've reduced the weight of my backcountry rack by about 30-40% from a similar rack built with ovals and camalots. and for me, on those desperate 5.6 leads, that weight savings makes a huge difference.

Brutus, who saved 5 ounces each by sawing his rawl drill handles in half


stevematthys


Jul 27, 2003, 5:36 AM
Post #104 of 118 (7539 views)
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grigri's should not be used for trad. period. any auto-locking belay device will put more force on the gear then any atc will. even if the gear is bombproof i would rather have my belayer be using an atc instead of a grigri.

ever notice in gyms how the guys with grigri's will go flying up in the air when their partner falls? and the guys with atc's do not fly up nearly as much? take that and put it on a loose nut on a run out slab. which belay device would you rather your belayer have?


the_crawler


Aug 2, 2003, 11:25 PM
Post #105 of 118 (7539 views)
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I know this isn't really the point of this decusion, (now that I have read through all the previous post I believe the point(s) are to 1. & 2. argue about what is "right" or "wrong" and 3. find statistical data relating to fall forces on different parts of the belay system) but what do you think holds the greater danger statistically, Being dropped by you belayer (letting go of the break hand) or taking a fall that generates enough force to rip pieces from the rock. The reason I bring it up is, reading the post I hear three types of respones, 1. No gri gri for trad, ever no matter what the numbers say 2. I'm using my gri gri for trad no matter what the numbers say 3. The numbers don't mean jack in the real world situations but what are they. The discusion stems around saftey for the climber (I like that cause thats my A$$ too) but trad climbing saftey is about minimizing risk, the most dangerous things (highest probabilty of getting you hurt) need to be addressed first followed by the lesser in order. Since no one is privledged to that order positively at any give time, you have to be able to adapt to the situation while in the situation to the best of your ability. I believe that climbers who are unwilling or unable to change their opinions or views on the order are more dangerous than any device made by Petzl.


eltusko


Aug 3, 2003, 12:42 AM
Post #106 of 118 (7539 views)
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Ok, here's my opinion, it's probably been stated over and over, but what the hell. I've got an atc and reverso. I've got a gri-gri sitting on my desk at work. I play with it when I'm bored. I use the reverso primarily and the atc as a backup if I or a partner lose another device. I figure that you don't have to worry about the "undynamic" belay of a gri-gri on lead falls if you're using either one of those. If you want to let your climber hang for some reason, such as drilling bolts, just use an autoblock or prussik to hold eliminate the need for you to hold tension on your device. Reverso + ATC + Prussik loop = lighter than 1 gri-gri, and the two devices work on double ropes for rappel, with an autoblock backup. I see no reason to lug my office paper weight gri-gri along.


c_kryll


Aug 3, 2003, 1:34 AM
Post #107 of 118 (7539 views)
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Just my $.02 but for those of you that complain you can't rapell on doubles with a gri-gri there is a way but I'm sure to get flamed for it.

Method 1: On anchors with rings or chains, you have the ropes tied together with the knot on one side of the rings. Using the rope that you are NOT planning on pulling to retrieve the ropes you attache your Gri-Gri. As you rap down the rope will be weighted so the knot braces against the rings, the climber with the gri-gri goes first so that the second can readjust the rope if needed and rap down as normal. Pull the rope as normal to retrieve.

Method 2: Simul Rap with your partner, there by only utilizing one strand of rope per climber. Pull rope as normal to retreive.

It was also asked how to increase friction on a reverso when using 1/2 or skinny ropes to reduce rope burn. I read good suggestions about adding an extra carabiner, turning the reverso around so the rope runs of the thin edge. You can also extend your device with a sling by either girth hitch or bunny ears to the belay loop. Adv: allows more control over a device. Dis-Adv: Puts rapell device at head level and loose hair may get caught or if you need to jumar back up it adds a step.

I highly recommend using an Auto-Block (8mm Cord) with any rapell setup, this gives your brake hand a place to sit and reduce the heat on your skin.

jmho

Chris


joegoesup


Aug 6, 2003, 6:41 PM
Post #108 of 118 (7539 views)
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I use the grigi in the gym and once and a while on sport, but never on trad. I think it puts too much force on the por, and it is hard to feed rope quickly. I use an atc or tube on trad.


bustinmins


Aug 16, 2003, 9:33 AM
Post #109 of 118 (7539 views)
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Well I've certainly learned a lot in this post. I'm a proud owner of a Reverso, ATC and Grigri.

I didn't understand why Petzl said don't use the Grigri on "Adventure Climbs" and now I do.

I will use my Grigri when being belayed in sport or top by a newbie partner - for my comfort. I will also use it myself because it is easier to just let them lock and stare at the wall while they figure out their next move.

However - I have seen how well the Reverso works in the auto-lock mode and will use that as my primary device for trad leading. I also like the way it grabs on the belay. However - I have never repelled with it - I can't see much difference with it compared to the atc - except that it feeds a little more poorly than the atc.

Always open to more information - keep typing - we newbies appreciate your opinions.

JD


badphish


Aug 19, 2003, 12:31 AM
Post #110 of 118 (7539 views)
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still if you have a grigri you should always take it with you when
doing trad or sport, much easier to rappel and clean gear.


joegoesup


Aug 19, 2003, 11:47 AM
Post #111 of 118 (7539 views)
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I stick with an atc for trad. I like my gri gri for sport, but it puts too much force on my trad gear.


sittingduck


Aug 30, 2003, 11:12 PM
Post #112 of 118 (7539 views)
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Probebly mentioned before on rc.com but I dont have the time to read through all the posts on the grigri subject, so here goes:
On aid-climbs I belay the leader with an ATC, on the breakhand side I clip in the grigri leaving enough slack to operate the ATC. In case my partner thakes a fall while I'm unconsentrated the grigri will arrest the rope when the slack is gone. Great safety benefit imo.


braon


Sep 6, 2003, 2:08 AM
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Re: trad... big no no [In reply to]
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So a gri-gri locks the rope up a couple of inches sooner than other devices. Does anyone honestly believe that this is going to significantly increase the forces on the belay system during a fall??? Sha right ... and like ... monkeys might fly out of my butt. This extra slippage might actually be useful if you were to take a 6 inch fall directly onto the anchors (reducing a factor 2 fall to factor 1). Seriously, I've logged a lot of BIG air time (I can't count the number of 50+ foot falls I've taken on two hands - Dan Osman's my hero) and the only time I've ever pulled a piece my belayer was using an ATC. There's absolutely no reason to be nervous about using a gri-gri to belay trad.


alpnclmbr1


Sep 6, 2003, 2:20 AM
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In reply to:
So a gri-gri locks the rope up a couple of inches sooner than other devices. Does anyone honestly believe that this is going to significantly increase the forces on the belay system during a fall??? Sha right ... and like ... monkeys might fly out of my butt. This extra slippage might actually be useful if you were to take a 6 inch fall directly onto the anchors (reducing a factor 2 fall to factor 1). Seriously, I've logged a lot of BIG air time (I can't count the number of 50+ foot falls I've taken on two hands - Dan Osman's my hero) and the only time I've ever pulled a piece my belayer was using an ATC. There's absolutely no reason to be nervous about using a gri-gri to belay trad.

Of course there wouldn't be any point in actually reading a thread your responding to. duh
It doubles the force on your last piece of gear in a test shown on page 5 of this thread.


braon


Sep 6, 2003, 2:38 AM
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missed that post trying to wade through all the senseless drivel. Thanks for the heads up


jt512


Sep 6, 2003, 2:43 AM
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In reply to:
missed that post trying to wade through all the senseless drivel.

I don't think that you're in a position to complain about the senseless drivel in the thread, given the fact that your first post just added to it.

-Jay


tenn_dawg


Sep 6, 2003, 3:25 AM
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In reply to:
So a gri-gri locks the rope up a couple of inches sooner than other devices. Does anyone honestly believe that this is going to significantly increase the forces on the belay system during a fall??? Sha right ... and like ... monkeys might fly out of my butt. This extra slippage might actually be useful if you were to take a 6 inch fall directly onto the anchors (reducing a factor 2 fall to factor 1). Seriously, I've logged a lot of BIG air time (I can't count the number of 50+ foot falls I've taken on two hands - Dan Osman's my hero) and the only time I've ever pulled a piece my belayer was using an ATC. There's absolutely no reason to be nervous about using a gri-gri to belay trad.

Sigh...Dear lord, deliver me from the ignorant!!!

Just kidding buddy, i'm sure you're not ignorant. You're not are you?;)

Travis


herm


Sep 8, 2003, 1:53 PM
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Use a gri-gri or what ever you like, but before you become a fast and light mountain climber guy, you will re-learn the intricacies of the old-fashioned sitting hip belay......................seriously.


Forums : Climbing Disciplines : Trad Climbing

 


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