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USnavy
Mar 3, 2009, 9:15 AM
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The other day I decided to take a few falls on some of my cams in "fair" placements to see which hold and which do not. I found out some interesting information regarding Omega Pacific’s .5 Link Cam…
Test parameters:
Rope: 10.3 mm Eldawis Ally non-dry
Belay device: Petzl GriGri
Belayer weight: Approximately 175 lbs.
Climber weight (with gear): 165 lbs.
Belay mode: Semi-static (belayer simply stood there, he did not jump, take in slack, feed out slack or anything else)
Total free fall distance: Nine feet (3.5 feet above piece, two feet slack)
Fall factor: Approximately .30
Both cams were brand new
The first cam I tested was an Omega Pacific Link Cam .5. When I fell on the cam, the placement failed and the cam pulled. The piece did slow me down some and I did notice a hard tug on the rope so the cam did suppress part of the fall before the placement failed. After I looked at the cam I noticed the axle was bent despite the relatively minor fall!
Next up was a Black Diamond C4 .4. I placed the cam in the exact same place as the OP .5 and in the same manner. I put a lot of effort into trying to make sure the placement was the exact same and the fall was the same. This time when I fell the cam held. When I climbed back up to the top I noticed the inside two lobes slipped and the cam inverted sideways some. After I examined the .4 I found the cam to be in perfectly good condition. The lobes still retracted smoothly and the axles were not visibly bent.
So the ultimate question is not, why did the OP pull and the BD hold (one can attribute the quality of BD’s cams to that); but why did the OP cam sustain such damage on such a minor fall?!? It’s disturbing to see this OP .5 bend on a factor .3 fall when I was only 3.5 feet above it. Remember the placement failed, so the OP .5 didn’t even have to bear the full blunt of the fall, yet it’s bent to hell…
So in summary, minor falls, OP placement failed, cam almost failed. BD cam held an even more severe fall, mainly on two lobes, in the same placement, with no post fall damage. I think it’s clear where my trust will lie from here on out.
Notice the position of the lobes in reference to a straight object:
You may notice how the BD is in perfect condition comparatively, despite the more severe fall:
Clicking on and zooming into the picture will show the details missed in these smaller versions.
(This post was edited by USnavy on Mar 17, 2009, 12:40 AM)
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a-e-jones
Mar 3, 2009, 9:49 AM
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don't you have a pull tester?
i vote pull test to see what happens
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andesite
Mar 3, 2009, 10:08 AM
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What is a 'fair' placement??? On the scale 'poor' - 'fair' - 'good', I would expect 50% of cams to blow out of fair placements so you have proved nothing to me.
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a-e-jones
Mar 3, 2009, 10:34 AM
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maybe it had to do with your .4 "slipping" leaving only the two lobes in contact while it sounds like the link cam still had 4 lobes of contact
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USnavy
Mar 3, 2009, 11:22 AM
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andesite wrote: What is a 'fair' placement??? On the scale 'poor' - 'fair' - 'good', I would expect 50% of cams to blow out of fair placements so you have proved nothing to me.
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patto
Mar 3, 2009, 11:55 AM
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Thanks USNavy some very thought provoking work. It would have been fantastic if you had taken photographs of the 'fair' placement in each case. As i currently stands this asks as many questions as in answers.
I suspect that the OP link cam was placed in a situation where the unused portion of the cam was extended and touching the rock. When the cam was loaded, this loaded the cam arm and torqued the axle. I doubt the axle was bent by normal cam contact forces.
There already has been one case on this forum of link cams breaking from this fashion.
(I say this because I have faith in OP design and quality control, the can should be fine in conventional placements.)
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clc
Mar 3, 2009, 12:07 PM
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interesting, but its what I have suspected all along. Navy doesn't know what he's doing. This tells us more about Navy's shitty cam placement than anything else. Fuck dude the cam was basically at your feet and it ripped? Stick to top roping.
I've heard of at least a few different brads of cams blowing apart from shitty placements. its a dangerous game.
so you have a defective cam or your placement sucked.
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johnwesely
Mar 3, 2009, 12:49 PM
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That cam is pretty tweaked.
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USnavy
Mar 3, 2009, 12:55 PM
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clc wrote: interesting, but its what I have suspected all along. Navy doesn't know what he's doing. This tells us more about Navy's shitty cam placement than anything else. Fuck dude the cam was basically at your feet and it ripped? Stick to top roping. I've heard of at least a few different brads of cams blowing apart from shitty placements. its a dangerous game. so you have a defective cam or your placement sucked.
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USnavy
Mar 3, 2009, 12:58 PM
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patto wrote: Thanks USNavy some very thought provoking work. It would have been fantastic if you had taken photographs of the 'fair' placement in each case. As i currently stands this asks as many questions as in answers. I suspect that the OP link cam was placed in a situation where the unused portion of the cam was extended and touching the rock. When the cam was loaded, this loaded the cam arm and torqued the axle. I doubt the axle was bent by normal cam contact forces. There already has been one case on this forum of link cams breaking from this fashion. (I say this because I have faith in OP design and quality control, the can should be fine in conventional placements.)
I remember the exact place I set the cams and I could probably get a pic the next time I go climbing.
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sbaclimber
Mar 3, 2009, 1:03 PM
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a-e-jones wrote: don't you have a pull tester? i vote pull test to see what happens
Having seen some of the vids from adatesman, I would think he should be able to tell us exactly what happens at what loads in "identical" placements. It might just turn out that the Link Cam axles aren't as stable....or something.
"Hiho, hiho, off to the lab lab go..."
(This post was edited by sbaclimber on Mar 3, 2009, 4:46 PM)
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altelis
Mar 3, 2009, 1:07 PM
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You are making some pretty large sweeping judgements about cams and companies when you have left so so many variables in place.
It has already been made clear that the link cam is a specialty piece that requires more care and thought when placing. The fact that you didn't even mention the known limitations of the link cam, and the fact that you didn't mention that you took these limitations into account suggests to me that you, in fact, didn't take them into account.
Until you redo the "test" with pictures of placements its meaningless. Until you can do a better job of explaining what in your opinion is a "fair" placement this "test" is useless.
For somebody who shows a pretty good head for science and lab procedures you have left some huge holes in place. Especially given the pretty damning tone of your post. Not fair. Not fair at all.
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granite_grrl
Mar 3, 2009, 2:07 PM
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altelis wrote: You are making some pretty large sweeping judgements about cams and companies when you have left so so many variables in place. It has already been made clear that the link cam is a specialty piece that requires more care and thought when placing. The fact that you didn't even mention the known limitations of the link cam, and the fact that you didn't mention that you took these limitations into account suggests to me that you, in fact, didn't take them into account. Until you redo the "test" with pictures of placements its meaningless. Until you can do a better job of explaining what in your opinion is a "fair" placement this "test" is useless. For somebody who shows a pretty good head for science and lab procedures you have left some huge holes in place. Especially given the pretty damning tone of your post. Not fair. Not fair at all.
Also, USNavy said the placement failed for the OP cam, which would mean that the BD cam probobly did NOT have the same placement as the Link cam. The Link cam could have blown away bad rock, or it could have been in a bit of a pod which the Link cam didn't sit in quite as well. Heck, he didn't end tell us what type of rock he placed it in!
IMO this test isn't very conclusive.
(This post was edited by granite_grrl on Mar 3, 2009, 2:09 PM)
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adatesman
Mar 3, 2009, 3:15 PM
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Hey USnavy-
Mind fixing the thread title? You have it as "OP Max Cam" rather than "OP Link Cam".
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Tipton
Mar 3, 2009, 3:28 PM
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Something else to keep in mind, the BD cam is a double axle where the OP is single. It isn't surprising to me that the OP bent before the BD. The BD should have received roughly half the load at each axle that the OP held on one axle.
Edit: It sounds to me like you placed them nearly tipped out. In this situation I'm definitely not surprised the OP failed prior to the BD cam. The BD C4s are capable of catching falls in a completely passive mode because of the double axles. If both placements were nearly tipped out then this isn't a shock at all, the BD cam is simply built to sustain more shenanigans then the OP.
(This post was edited by Tipton on Mar 3, 2009, 3:36 PM)
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mexclimber
Mar 3, 2009, 3:31 PM
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The lobes come like that new. I shopped several places before buying my .5 OP because I thought something was wrong and they were all identical. That's the way they sit and it doesn't affect the performance at all. So without knowing any more details about your "test" and seeing your cam before me, I'd say it's not bent based on my experience with my own .5 OP. Go to your local shop and see for yourself.
My 2 pennies.
John
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michaellane
Mar 3, 2009, 5:09 PM
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Hey, Navy ...
If you'd like us to take a look at that cam, call us for a Return Authorization and we'll inspect it for damage.
The lobes look a little tweaked, but it doesn't mean the axle's bent. The inspection will reveal if it is, but my bet is that it's not.
The inner-most links (the ones attached to the axle) require a lot more rotation than any other cam on the market. As such, they require a little more tolerance between the inside diameter of the link and the outside diameter of the axle. Because of that relationship and that the springs apply some side force to the lobe assemblies, sometimes, they can sit slightly askew on the axle. I'm guessing that's what we're seeing in your photos.
Why'd the Link Cam pop when the Camalot didn't? I wish I could tell you. There isn't a lot of information or photos included about the type of placement, so it's impossible for me to speculate. However, we've found through exhaustive testing, as others here have mentioned, that minor variables can significantly effect the holding power of one cam over the other ... or even the same cam from one placement to another in the same feature.
But if you'd like us to give your cam a checkup, we'd be happy to.
--ML
___________________
Michael Lane
Omega Pacific
800.360.3990
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vegastradguy
Mar 3, 2009, 5:26 PM
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thanks for posting so quickly michael.
a couple of thoughts.
first, and foremost- the link cam is NOT a standard cam and cannot be treated as such. there are different variables that you have to consider when placing this cam as opposed to placing another cam like a BD. i've never considered this cam a beginners cam simply because of this fact.
second- like other posters have pointed out- what is a 'fair' placement? the margin for error is pretty small with small cams like these, so the difference between a fair placement and terrible one is not that big. id like to see pictures of the placement with both cams in it.
third- the axle doesnt look bent, and from above, it looks like the lobes dont necessarily come in a straight configuration (a little weird, but i'm not an engineer). a before picture would be useful here- anyone got a shot of a brand new .5 link cam?
fourth- you mentioned that the BD slipped an 'inverted sideways'- does this mean that the stem was not oriented downward for these placements? if thats the case, then that probably contributed to the links failure and it was probably random luck that the BD didnt. any rotation in a cam that small in what i understand to be less than an ideal placement in a non-parallel crack and who knows what can happen.
a couple of other thoughts.
you're still new to this game, so i would say that if you feel the need to field test cams again, you'd be better off using a bigger cam- hand size or so. small cams are finicky, and while these arent super small cams, they do have much smaller margin for error than say a #2 camalot.
all else aside, this does show that placements- fair or not, can fail and folks who are new to the game need to understand that. spending time following an experienced leader and also time spent on ground school and, ideally, on a few pitches of aid, can go a long way toward teaching new folks what a good/fair/marginal/bad placement looks/feels like before they find themselves 50' up and wondering if the gear underneath them will hold a fall.
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steady_climbing
Mar 3, 2009, 5:45 PM
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Keep it up USNAVY!!! Lets see, we now have a thread concerning your evidently poor belaying skills and, now one showing poor gear placements.
Just climb, stop filling this site with crap.
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maldaly
Mar 3, 2009, 5:59 PM
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Should have used a Pink TriCam...
Mal
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Adk
Mar 3, 2009, 6:10 PM
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vegastradguy wrote: a couple of thoughts. all else aside, this does show that placements- fair or not, can fail and folks who are new to the game need to understand that. spending time following an experienced leader and also time spent on ground school and, ideally, on a few pitches of aid, can go a long way toward teaching new folks what a good/fair/marginal/bad placement looks/feels like before they find themselves 50' up and wondering if the gear underneath them will hold a fall.
Well said!
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patmay81
Mar 3, 2009, 6:22 PM
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I have to say I have had link cams in what I would consider "fair, or marginal" placements hold 6+ foot falls of similar or greater fall factors. One time a BD blew out and the link cam caught in the same fall, the bd I thought was a bomber placement and the link cam was an oh shit placement.
I'd say there are too many subtle variables for a field test to yield any kind of serious results. and your link cam looks fine to me, id climb over it.
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bandycoot
Mar 3, 2009, 6:59 PM
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Well, almost immediately after the C4 Camalots came out, I fell on an almost brand new 0.5 C4. Instead of thinking I bent the axle, I KNEW I bent the axle. The fall was around 5-6', and maybe factor 0.5? The axle was visibly bent, and the cam lobes were thus stuck in the closed, or fully cammed, position. Your logic is flawed. You can't make sweeping assumptions based on a single data point that isn't statistically significant, especially with so many variables and factors and imperfections applying strange forces in an outdoor crack real world scenario. Despite destroying the cam, I didn't declare that I would stop climbing on the things, instead I kept climbing on them all weekend and plan to buy more in the future. S*** Happens! :)
Josh
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sungam
Mar 3, 2009, 7:42 PM
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Wow, it seems a fair number of folks on here missed the point.
The f*ing axle seems to have warped slightly due to the fall.
Can you take a top-down picture as well? Like, of the link cam so we can see it more clearly?
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granite_grrl
Mar 3, 2009, 7:53 PM
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sungam wrote: Wow, it seems a fair number of folks on here missed the point. The f*ing axle seems to have warped slightly due to the fall. Can you take a top-down picture as well? Like, of the link cam so we can see it more clearly?
If you take a larger BD cam (I only say BD because they are the only larger cams that I have) you can see an amazing amount of play in the lobes. Not having used link cams, I'm not sure how much play their lobes have, but it's something to consider.
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