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one900johnnyk
Oct 2, 2003, 10:54 AM
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it's more bulky and cumbersome... why not tie two loops at each end and use it like that. you don't have to carry as much cord and there's less of a clusterf uck at the tie in pt. ... i did this to all of mine and like it a lot better... just curious if anyone has any good reasons NOT to do this. thanks!
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hellclimber
Oct 2, 2003, 11:20 AM
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Good reason: Without considering the knots in the cordelette, your way of using the cordelette has only half the strength of a cordelette tied in a loop. I really don't see your point regarding the clusterf_ck. When I use a cordelette for an anchor, it seems pretty tidy and simple too me (but then again I'm somewhat of a noob so someone more experienced might have more valuable input). hellclimber
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alonfw
Oct 2, 2003, 11:37 AM
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I don't understand exactly what you mean by two loops... the only ways I can figure to do that would require more cord/webbing when you consider the point of a corde/webelette is to equalize 3 points, and keep it redundent. Once you know how to do it, a cordelete is the least cluster of any anchor setup.
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lilcapntravis
Oct 2, 2003, 12:31 PM
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i think what we're talking about here is using a single strand of cordolette instead of having it tied into a loop. if you used this to equalize a 3-point anchor, you'd be tying a knot with 4 strands instead of 6. the only downside that i see is that you're losing 50% of the strength on two of the points. would that be a problem with 7mm cord? i hate big bulky knots on the powerpoint.
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corpse
Oct 2, 2003, 12:48 PM
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I recently used some stuff webolette that was sewn with a loop at each end.. It certainly made setting up an anchor a bit faster and neater.. each loop goes through a biner, and then the middle of it gets clips in another biner, then tie a fig8 and its done. Tying a fig 8 with webolette is something I see as a practiced skill, trying to get it to look nice that is (and a pretty knot is a strong knot, right?) As for strength, how much are you truly really losing? (I suppose if i knoew the strength of the webolette I could guess).. Also, I'd think webolette can be sewn up real strong, but what about cordolette? I'd probably rather tie a fig 8 in 4-6 pieces of cord than webbing.
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johnnord
Oct 2, 2003, 1:02 PM
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I use a single strand kevlar cord with a figure-eight on a bight on each end. I't way strong (stronger than the rope) and much lighter and less bulky. I saw the idea in one of the mags about a year or so ago. It's also cheaper than buying one of the spify "webbolettes" that are on the market.
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herm
Oct 2, 2003, 1:52 PM
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I'm not convinced; I like them for aid climbing, they do simplify complex anchors. I am convinced that I can move faster with out one on free routes. Equalizing a couple runners isn't that hard. In the real world, my experience with cordlettes is that they are slow to rig and unrig, and they require an extra peice of gear. I know that everyone likes them, and I'm good with that. I just think that it isn't the right tek for fast and light types. I would be curious to hear from some badd-a@@es who do big free routes in fast times. Does any one use them in the mountains?
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chugach001
Oct 2, 2003, 2:12 PM
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I'm not sure I understand - There are two things a corelette does, it equalizes 3 pieces from a variety of angles (as your climber climbs right, it equalizes to the right and ditto for left. The three "free-floating" strands to your gear make this possible in the cordelette. It also eliminates shockloading if one or two pieces pull. Does your system truly equalize 3 pieces? Meaning, that if one pulls, the others get no shock loading? If two pull, the remaining piece gets no shock load? The big bulky knot in a cordelette is the trick for doing this. Let me know what I missed. Jeff
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reno
Oct 2, 2003, 2:19 PM
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Besides the obvious uses, there is a shock-load limiting factor. Further, you can use the cordlette as a emergency prusik to escape the belay, ascend a rope, etc. I carry two... both 5.5 Spectra, 21 feet long, tied into a loop with triple fisherman knot. I'm finding them to be very useful in a variety of settings. Another option is to carry one cordlette loop and one webolette. Then you have even more options.
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socalclimber
Oct 2, 2003, 2:23 PM
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Uh, now I'm not sure about what you are saying. A cordelette will equalize TWO or more placements. And I agree, I don't understad what this post is about.
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hugepedro
Oct 2, 2003, 3:13 PM
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In reply to: it's more bulky and cumbersome... why not tie two loops at each end and use it like that. you don't have to carry as much cord and there's less of a clusterf uck at the tie in pt. ... i did this to all of mine and like it a lot better... just curious if anyone has any good reasons NOT to do this. thanks! Probably not a good idea. See links below to test data.
In reply to: I use a single strand kevlar cord with a figure-eight on a bight on each end. I't way strong (stronger than the rope) and much lighter and less bulky. I saw the idea in one of the mags about a year or so ago. It's also cheaper than buying one of the spify "webbolettes" that are on the market. Even worse of an idea. Spectra/Kevlar cord is even weaker than 7mm nylon when you tie a figure-8 in it. You are paying more for a weaker anchor (but you're saving a couple ounces of weight). If you follow the links below to test data you will see that it breaks at the knot at about 7.5kn. Here's a link to test data (Click on the "view paper" link under the section titled "Comparative Testing of High Strength Cord."): http://www.xmission.com/~tmoyer/testing/ And here's a link to another thread where we discussed this extensively. I'm pointing you to a post in that thread by JT512 that has a link to test results from Black Diamond. http://www.rockclimbing.com/forums/viewtopic.php?t=23745&postdays=0&postorder=asc&topic_view=&start=22
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dingus
Oct 2, 2003, 3:45 PM
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I've almost completely quit using cordelettes. Too slow, too bulky, to cordeletteish. Back to the Old School for me. They're still good for walls and whatnot. But I strongly prefer a sling anchor belay. DMT
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ricardol
Oct 2, 2003, 3:50 PM
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there was a thread a while back on this .. look it up for more info .. the bottom line was that the knots you tied on the ends of your cord are a weak point .. on the sewn webolettes there isn;t a problem because the bar-tacking is full stfength .. there was some testing that showed that the knots broke at a point that was lower than a regular looped cordelette. .. both work .. one is stronger .. i carry a tech-cord 5mm cordellette (20ft)... and a webolette .. -- ricardo
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attitude
Oct 2, 2003, 4:09 PM
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It's easier to sling large blocks with a cordelette loop. The longer the cord, the bigger the block.
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vegastradguy
Oct 2, 2003, 4:57 PM
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its already been said, but here's a review: 1) by tying 2 figure-8's on the end of a line, you're reducing its strength by 20% on each end. 2) you're also losing strength because you dont have two lines per anchor point. 3) you dont have as much cordlette on you as you would if you had a loop. this is handy when you have emergencies and such and need some line.... 4) a loop is twice as strong and you lose less strength at the knot, since theres only one, not two. that's it in a nutshell. a prefab webolette is fine since its full strength throughout, so you dont lose anything through knots.
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arlen
Oct 2, 2003, 5:20 PM
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The thing is, if you look at the numbers for knot strength, only a 7mm nylon cordelette is totally, uncompromised bomber. I stopped carrying mine, because 1. the grapefruit-sized knot sucks up a lot of length (and angle of pull) 2. it's bulky to rack 3. if i need a prussik, i just use my prussik
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chalkbag
Oct 2, 2003, 5:58 PM
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In reply to: Good reason: Without considering the knots in the cordelette, your way of using the cordelette has only half the strength of a cordelette tied in a loop. That's not true. Even with cordelette loop there is exactly one strand running through the anchor biners so there is no 50% reduction in strength if you don't consider the knots. The reduction in strength in single strand cord with figure-eights at the ends comes from the figure-eight knots and _not_ from using one strand instead of a loop. If you look at the test results in the links posted above, you'll see that a) Spectra cord with figure-eights breaks at the knots; b) reduction in strength specified on climerware.com matches the reduction in strength of the figure-eight know found by Tim Moyer.
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alpnclmbr1
Oct 2, 2003, 6:06 PM
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In reply to: In reply to: Good reason: Without considering the knots in the cordelette, your way of using the cordelette has only half the strength of a cordelette tied in a loop. That's not true. Even with cordelette loop there is exactly one strand running through the anchor biners so there is no 50% reduction in strength if you don't consider the knots. The reduction in strength in single strand cord with figure-eights at the ends comes from the figure-eight knots and _not_ from using one strand instead of a loop. If you look at the test results in the links posted above, you'll see that a) Spectra cord with figure-eights breaks at the knots; b) reduction in strength specified on climerware.com matches the reduction in strength of the figure-eight know found by Tim Moyer. How many time are we going to go through this? A loop is always close to twice as strong as a strand of the same material. And a figure 8 knot tied in kevlar loses about 40%.
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hugepedro
Oct 2, 2003, 6:21 PM
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In reply to: How many time are we going to go through this? A loop is always close to twice as strong as a strand of the same material. (Ha ha, now I'm going to really bug you.) Until someone satisfactorily explains to me - why. I've asked this question before but nobody has given me the physics behind the answer. What I don't understand is this. A loop does have 2 strands, so obviously each takes 50% of the total load. But at the point where the bite is clipped to the biner there is only 1 strand. There are not 2 strands running through the biner. So wouldn't the 1 strand at that point be loaded with the full 100% load, the combined load of the 2 strands? I gots ta know.
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fitz
Oct 2, 2003, 6:58 PM
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In reply to: Until someone satisfactorily explains to me - why. I've asked this question before but nobody has given me the physics behind the answer. No one is going to 'prove it', because it simply is not true. The 'bend', where the single strand passes through the gear biners, is generally the spot where the cord will break if you load test a cordelette rig. Making a 'web-o-lette' setup using cord is weaker at two of the anchor points because a) some strength is lost in the knots and b) the small loops after each knot create a slightly tighter bend around the clipped biners. Practically speaking, both these differences are not large if you use 7 mm perlon. I had this conversation once with rrrAdam and then tested his rig (15' 7mm, overhands each end) at a staging shop here in LA. Since then, I still use an 18' 7mm loop, since I'm used to it, but I don't hesitate to untie it and use overhands to get the length to equalize either an extra piece, or a piece that is not clustered as nicely as I would like. To answer another question, I do take a cordelette to the mountains, though I generally use rope tie in for speed on those routes. I've found the cord handy for makeshift hauling, self rescue, etc., a number of times, so I put up with the weight. I've always used 7mm perlon, because the super-strong stuff feels stiff to me, and melts too easily (or at least it used to). From the BD testing earlier in this thread, it seems I've been lucky on strength as well. -jjf
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chalkbag
Oct 2, 2003, 6:58 PM
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In reply to: What I don't understand is this. A loop does have 2 strands, so obviously each takes 50% of the total load. But at the point where the bite is clipped to the biner there is only 1 strand. There are not 2 strands running through the biner. So wouldn't the 1 strand at that point be loaded with the full 100% load, the combined load of the 2 strands? That's exactly what I was saying. If somebody has pointers to tests results showing different data, I'd really like to see them - quite seriously. Might settle for an explanation too... [edited to remove an incorrect reference]
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one900johnnyk
Oct 2, 2003, 7:03 PM
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In reply to: i think what we're talking about here is using a single strand of cordolette instead of having it tied into a loop. if you used this to equalize a 3-point anchor, you'd be tying a knot with 4 strands instead of 6. the only downside that i see is that you're losing 50% of the strength on two of the points. would that be a problem with 7mm cord? i hate big bulky knots on the powerpoint. haven't had time to read lots of the posts yet, but this is what i'm talking about... to help people get it, the two loops at the end of the cord hook into two of the pieces and then the middle is pulled up so i bight sits in the biner of the third. then you tie an overhand or eight on a bight at the bottom to prevent any shocks should one piece fail.. it is equalized. making this with webbing is a good idea, i have some '9/16 lying around, i might try it instead of cord. for me, strength is not an issue, i would feel safe hanging from the system i have described. you'd have to be really fat for 7 mm cord to break on you...
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ep
Oct 2, 2003, 7:17 PM
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In reply to: what you have just read are the ramblings and opinions of an absolute idiot. please ignore and go about your business... Well at least he's honest about it.
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alpnclmbr1
Oct 2, 2003, 7:56 PM
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In reply to: Real World Loop Strength On Fri, 8 Jan 1999, Russ Walling wrote to Chris Harmston : >Hi Chris, >Had a few questions I was hoping you could help me with. >Q: Say a cable or webbing is rated to X. Is there a quick and easy >convert to find loop strength, assuming the bond is full strength? How >about real world loop strength, as loaded between biners, not just >math? Most people would assume that the strength of a loop is twice the strength of the single strand breaking strength. What I have found is that this is not correct for two reasons. First is that the tack does factor in. It is not always easy to ensure that the tack is stronger than the webbing. So take off 5%. Second is that the single strand strength is obtained by testing over large radii. Loops are tested over 10 mm pins. The pins weaken the loop as you should expect. So remove another 5%. What I find is that the loop strength is about 10% weaker than 2 times the single strand rating. This is plus or minus 5% or there abouts. >Q: same Q as above, but instead of a loop, a rabbit runner config, ie: >loop at each end, single strand in the center. Load applied in each >loop. Here the tack does not factor in as much. Only the effect of the pins. So take of 5%. This is pure assumption because I have not looked at this data myself (even though we had rabbit ears in the bivy and Big Wall I tent-we use loops now). I forgot to answer the carabiner runner question. Basically the biners are like a 10 mm pin. Sometimes the radius of the biner is too curved and then the runner breaks even lower. Also, wide runners put greater load on the carabiner gate side and biners are found to break significantly below ratings when tested with wide runners. Chris Harmston (chrish@bdel.com). Quality Assurance Manager. Materials Engineer BS, ME. Black Diamond Equipment Ltd. 2084 East 3900 South, SLC, UT 84124 phone: 801-278-5552 DISCLAIMER: Unless otherwise indicated, this correspondence is personal opinion and NOT an official statement of Black Diamond Equipment Ltd.
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alpnclmbr1
Oct 2, 2003, 7:58 PM
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In reply to: Subject: test report, knots in spectra and nylon From: matt.dimeo@conexant.com Newsgroups: rec.climbing Date: Thu, 08 Jul 1999 20:17:56 GMT Chris Harmston at Black Diamond showed his typical generosity and pull-tested some samples for me, so I'm passing on the results to add to the general knowledge base. First some background: some months back there was a rec.climbing discussion about Webolettes and their application. At the time, I brought up the possibility of making your own out of spectra cord with loops tied in the ends. This test was meant to check the feasibility of that. I figured that if I could tie a spectra-cord "webolette" with strength comparable to a 7mm nylon cordelette, I'd do so, preferring cord to webbing for self-rescue reasons. As it turns out (see results below), it's not even close. Nylon cord is stronger than I had remembered, for one thing, and having a single strand of cord cuts the strength nearly in half over a loop. I actually figured that out before I sent the samples off, but after I had already bought and cut the cord. This probably would have been obvious to many of you. I sent three samples each of the following configurations, and got these results: Configuration #1: spectra cord loop, tied with triple fisherman's (i.e. a normal cordellete) Samples all broke @pin, at 3717, 3467, and 4034 lbf. Configuration #2: 7mm Nylon cord loop tied with double fisherman's (cordelette) Samples all broke @pin, at 3286, 3605, and 3299 lbf. Configuration #3: spectra cord with figure eights tied at each end. Backup knots were used, but made no difference (they didn't come tight). This is the webolette configuration. Samples all broke @knot, at 1779, 1793, 1884 lbf. Configuration #4: As #3, but with a triple-fisherman loop in each end (see below). Broke at knot, at 1745, 1725, 1709 lbf. The knot tied in #4 was created by feeding a triple fisherman knot through itself. To tie it, start tying a 3-fish around a pencil, then feed the short end back through along the pencil, pull out the pencil, and tie the other half of the 3-fish. You end up with a small loop. Conclusions and observations: 1. nylon cordelletes didn't break much weaker than spectra, so if you use spectra cordelletes because you think they're stronger, you might be wasting your money. 2. The triple fisherman loop I sort-of invented didn't break any stronger than the figure eights. Actually a little weaker. all cord used was new. The spectra was 5.5mm blue water. The nylon was 7mm, don't know the manufacturor. The test rig used 10mm pins at 4"/minute. Send email if you have any questions about the above. Claimer and Disclaimer: Any mistakes above are mine, not Chris's, and not Black Diamond's. If you make safety decisions based on any of the above data, and your head pops off as a result, it's your own damn fault. -m@
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