The claim that the gri-gri will put higher loads on the pro is based on analyses of forces that don't account for friction in the system. Most protection systems have enough friction in them that no rope slips through the belay device and so a non-slipping belay is provided by all devices, locking or not. The result, which we all suspect anyway from numerous actual experiences, is that a gri-gri belay doesn't result in gear failure any more than other devices in almost all cases.

This leaves a few worst-case scenarios: high fall-factor falls on the first piece of pro or on a belay redirected through the anchor; situations with potentially high forces and very little friction. In these cases, it seems to me that there is a choice of undesirable outcomes. The gri-gri locks up and makes the rope do most of the work, resulting in high rope tensions and so high loads on the anchors. On the other hand, non-locking devices do not provide enough force multiplication for the climber's grip to hold high rope tensions, so the rope tension builds up to the grip limit and the the rope runs through the belay device. This provides a "safety valve" that keeps rope tensions from building up, so anchor loads are lower, but now the belayer (who from my observations will almost always be ungloved) has to control a running rope, resulting in either loss of control or possibly severe injury to the belayer or both.

There are a number of situations between the extremes when a dynamic belay is a good idea, either to keep the forces on the anchors low or to prevent a leader on overhanging rock from smacking the wall hard on a short fall. In these cases, the belayer must consciously initiate the dynamic belay, because the frictional forces keep the rope tension at the belayer within the grip limit.

[..]

What to do? It seems to me that there are good arguments on both sides, remembering that most of the time it isn't going to matter. If you are belaying with a non-locking device without gloves, then the gri-gri might be the better option.

However, there are other issues for free-climbing: isn't easy to pump out slack fast to a leader who is making a clip, and many belayers adapt by holding the cam open with the non-braking hand. This leads to the possiblility of the cam not engaging in time during a fall, resulting in a dropped leader. There have been a number accidents when this has happened, it is not just a theoretical possibility.

If you are willing to wear gloves, are able to pay attention, and have learned the dynamic belay, then the non-locking device still seems to be a significantly better choice to me, but the choice is by no means as clear-cut as "don't use gri-gri's for trad."

The claim that the gri-gri will put higher loads on the pro is based on analyses of forces that don't account for friction in the system.

The result, which we all suspect anyway from numerous actual experiences, is that a gri-gri belay doesn't result in gear failure any more than other devices in almost all cases.

This leaves a few worst-case scenarios: high fall-factor falls on the first piece of pro or on a belay redirected through the anchor; situations with potentially high forces and very little friction. In these cases, it seems to me that there is a choice of undesirable outcomes. The gri-gri locks up and makes the rope do most of the work, resulting in high rope tensions and so high loads on the anchors.

Experiments have shown that a belayer using a gri-gri can reduce anchor loads significantly by executing a well-timed jump.

It is unreasonable to imagine that a belayer on a multipitch trad climb will be able to apply the jump technique successfully; it is essentially a sport-climbing practice.

If you are willing to wear gloves, are able to pay attention, and have learned the dynamic belay, then the non-locking device still seems to be a significantly better choice to me, but the choice is by no means as clear-cut as "don't use gri-gri's for trad."

You have one "choice":

1. Teach your partner how to belay, then climb. Grigri or atc.

YOU ARE WRONG
It is still better to have 50/50 chance that Gri Gri will catch you then climbing and looking dawn to check if your belayer is doing her/his job.
( this has happend to me when I climbed first year in Canada )

YOU ARE WRONG
It is still better to have 50/50 chance that Gri Gri will catch you then climbing and looking dawn to check if your belayer is doing her/his job.
( this has happend to me when I climbed first year in Canada )

How do you come up with that? In the past, the grigri was assumed to create higher forces on gear due to its relatively static method of catching a fall.
Since then people have actually attempted to measure the forces involved in various scenarios with various belaying methods. The Italian study, a paper by REI, and a number of others all seem to support the idea that a grigri produces higher fall forces than an atc type device.

This from a college profesor?
Got any reliable data to back this up?
You are a 60 year old climber. As I seem to recall, you like to climb on double ropes, and usually at the gunks. Sounds like an authority on the grigri to me.
Pretty sketchy reasoning. (me and my friends have been using grigri for trad climbing for years, and we are not dead????)

I interpreted rgold's point to mean that, in most fall situations, the forces exerted upon the ATC type device do not exceed the threshold beyond which the belayer is unable to arrest the fall statically, and that the devices are therefore somewhat equal. No?

The claim that the gri-gri will put higher loads on the pro is based on analyses of forces that don't account for friction in the system.

The result, which we all suspect anyway from numerous actual experiences, is that a gri-gri belay doesn't result in gear failure any more than other devices in almost all cases.

Why would using a gri-gri be the more important prerequisite to concluding that neither device results in gear failure more often than the other? I'd think it should be the other way around. Given the static nature of the gri-gri, shouldn't the real question be how often are leader falls onto ATC's caught statically?

That makes about zero sense.
You are saying that a lack of familiarity is preferable in evaluating a belay device???

I like how neither of you have mentioned a word about why you would want to use a grigri on a trad climb first place. You seem to be trying to sell something, yet you hesitate to mention why???

YOU ARE WRONG
It is still better to have 50/50 chance that Gri Gri will catch you then climbing and looking dawn to check if your belayer is doing her/his job.
( this has happend to me when I climbed first year in Canada )

Pedantry

No, I only questioned why you'd discount someone's conclusion simply because they appeared to primarily use an ATC. The gri-gri's belay is already known to "not slip" (i.e., it's static).....I'd think the more interesting question would be whether or not (and if so, to what extent) a catch on an ATC is static.

YOU ARE WRONG
It is still better to have 50/50 chance that Gri Gri will catch you then climbing and looking dawn to check if your belayer is doing her/his job.
( this has happend to me when I climbed first year in Canada )
_________________
Nothing worth having comes easy.
Looking for partners.

Definition
~"an ostentatious and inappropriate display of learning"

What thread on this site could be characterized as being ostentatious. This one??? Really?

"inappropriate display of learning"

What would that be?

How do you come up with that? [The anchor load disadvantage of the gri-gri is based on the assumption of low system friction] In the past, the grigri was assumed to create higher forces on gear due to its relatively static method of catching a fall.

The Italian study, a paper by REI, and a number of others all seem to support the idea that a grigri produces higher fall forces than an atc type device.

This from a college profesor?

Got any reliable data to back this up [lots of trad falls being held by gri-gris without higher occurrence of gear extraction] ?

You are a 60 year old climber.

As I seem to recall, you like to climb on double ropes, and usually at the gunks. Sounds like an authority on the grigri to me.

Pretty sketchy reasoning. (me and my friends have been using grigri for trad climbing for years, and we are not dead????)

This is the first time after numerous discussions where you felt(implied?) the grigri was the answer to an ungloved ff2.

How does what belay device you use have anything to do with the reduction in forces caused by jumping while catching a fall? It doesn't and you should know that.

This and the following seems to imply that [jumping and letting rope run] are the only two methods of introducing a dynamic belay into a multipitch belay scenario. That is kind of funny given that they are not even the most commonly used methods.

Since most people don't climb with belay gloves, this would seem to be endorsing the idea that you think everyone should be using a grigri for trad

So according to you the only reason to use an atc type device is if you use a belay technique that again according to you hasn't been practiced for thirty years?

Volunarily letting the rope run without gloves and with no practice seems pretty stupid to me, so it is hard to see this feature as an ATC advantage.

The result, which we all suspect anyway from numerous actual experiences, is that a gri-gri belay doesn't result in gear failure any more than other devices in almost all cases.

I use my grigri for everything from sport to bigwall.

CLIMB MORE. THINK LESS.

To diverge - I thought another way of doing a dynamic belay was, rather than letting the rope slip through your hand while holding your hand in place, gripping the rope tightly while moving your hand toward the device. Would this offer the same degree of dynamism to the belay without as much risk of rope burn on the belay hand?

Ok so there it goes:
Gri Gri does not lock by itself that I have proven to myself and others when last year in the gym I ended up climbing about 6 or 7 meters up and then I let go ( she wasn't holding the rope because I told her not to)

I'm not ignorant, you got that wrong.
Last year was my first year climbing in this country ( Canada ) and I was climbing easy trad up to 5.5 with people that I have met in the gym.

This year I am climbing with 4 good people from that gym and a few from this web site.

From experience now I rather bolder my house or do some traversing alone at the bottom of local crag than go climbing with this people again.

ATC's handle better, are better for rapelling, and weigh less. They put less load on the anchors---in some situations---but if the belayer cannot control the rope slippage that is the mechanism for load reduction, the reduced anchor load comes at the price of a dropped leader, serious burns, or both. If you are choosing between a gri-gri and an ATC without gloves, then I don't find the choice clear-cut. If you are willing to wear gloves, than the ATC is a better device for belaying trad. Otherwise...choose your poison.

No wonder you're looking for partners [all the time no doubt] if that's how you think about belaying...!

Have you heard of the Darwin awards?
Petzl tells you specifically to hold the rope, and depending on the rope width, how you fall and other factors, a grigri won't always lock up.
The next time you want to find out if it locks or not, measure and tie a knot so you won't hit the floor or make your belayer hold the rope further down.
The point of the grigri being a static device is that it lets very little rope through once it is locked. The fact that you can fall further before it locks does not make it dynamic.


This seems a bit contradictory to me. So you climb with these people this year even though you would rather not?