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yokese
Mar 6, 2009, 5:07 AM
Post #126 of 177
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curt wrote: jt512 wrote: ....Don't you think a leader ought to know the difference between a good placement and a bad one? Jay Well, if you never fall, they're all good.  Curt
Funny, but actually there is A LOT of (scary) truth in that affirmation.
I'll rephrase: they're all good, until you fall.
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robbovius
Mar 6, 2009, 6:03 PM
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adatesman wrote: jt512 wrote: It seems that the test may actually have subtracted from our body of knowledge. Are you saying that reading this made us dumber, according to the statistics? 
OH, and how/why would/should that/this thread be different than any other thread on rc.knorb?
(This post was edited by robbovius on Mar 6, 2009, 6:04 PM)
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k.l.k
Mar 6, 2009, 6:26 PM
Post #128 of 177
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robbovius wrote: adatesman wrote: jt512 wrote: It seems that the test may actually have subtracted from our body of knowledge. Are you saying that reading this made us dumber, according to the statistics? OH, and how/why would/should that/this thread be different than any other thread on rc.knorb?
Because this thread has really raised the bar. And it did so by building on some really solid foundations. Remember our JTree Link Cam thread? I'm not thinking so much of the original incident in which an unfortunate decked on LST, so much as the inadvertent re-enactment by one of our RC residents who went back to the climb and managed (apparently) to recreate the original mistake.
http://www.rockclimbing.com/..._reply;so=ASC;mh=25;
Those n00b lurkers and posters to this thread who haven't read this magnum opus, should start at page one and continue until the bitter end. Pay special attention to the posts by MalDaly, Rgold, and Michaellane. Read the Kodas paper, and the ensuing discussion. Read between the lines to try and work out what happened in the re-enactment of the original accident.
The bottom line? This thread appears to be the second unfortunate incident involving link cams, user error and rc.com. And Marx was right: History repeats itself, the first time as tragedy, the second time as farce.
(This post was edited by k.l.k on Mar 6, 2009, 7:06 PM)
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psprings
Mar 7, 2009, 6:17 AM
Post #129 of 177
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Couple questions Navy (I'm not flaming one way or the other, just curious).
Were you putting both cams in the same spot? Range-wise, they should both fit in the same placement.
Which sort of leads to the fact that appearances can be deceiving. That crack looks good- like a bomber finger lay-back. Is it flaring, parallel? Shallow and bottoms out or deep? I'm guessing it's funky if you had to place the cams in different spots (due to the length/depth difference of OP lobes).
What were the lobes of the OP cam like with regards to placement? Was it almost fully retracted? Closer to tipped out?
Thanks for this, though. K.I.S.S. (and light) has always been my motto, Metolius 4EVAR! :D
(This post was edited by psprings on Mar 7, 2009, 6:20 AM)
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rgold
Mar 8, 2009, 5:30 AM
Post #130 of 177
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Someone new to placing gear places two cams, takes moderate falls on them, and one cam pulls. Nothing about this is all that surprising. The fallacy is an implied assumption that the results are explained by the difference in the manufacturer. The same results might have happened if the same make cam was placed twice.
Although we can't see the actual placement, we can see the crack just above the placement.
It is clearly very irregular and seems to be flaring higher up. The rock surface itself also has very thin scaley features, making one wonder whether the surface features inside the crack are analogously questionable.
There isn't too much involved in placing a cam in a parallel-sided crack in good rock, but cams in the type of crack pictured here are a very different proposition. All that irregularity means that even micro-movements could change the placement significantly, the short clip-in maximized the chance for such motions, and the potential for surface crumbling adds to the possibility of a lowered coefficient of friction.
Under these circumstances, pilot error is a significant possibility, even if the pilot in question is not inexperienced. The disturbing message, and I think there is one, is that cams, fantastic as they are, can be very subtle to place and extremely difficult to judge when the crack geometry is not very uniform.
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evanwish
Mar 8, 2009, 5:42 AM
Post #131 of 177
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i believe he stated they were as close to the same spot as possible.
it seems we're all looking into it to deep.. just in that particular placement, the link cam didn't do too well.. kinda a bummer.
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moose_droppings
Mar 8, 2009, 6:52 AM
Post #132 of 177
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Your right, "as close to the same spot as possible". Since the two cams have head widths that are different sizes, the two placements couldn't have been in exactly the same spot.
Who knows what else hasn't been represented accurately too.
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zeke_sf
Mar 8, 2009, 10:25 AM
Post #133 of 177
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USnavy wrote: From my test its clear that the brand and design does mater to some degree. Anyways that’s all irrelevant. What is relevant is why did the small fall tweak the axle?
I trust the minds and manufacturer who made that cam more than I trust the highly inconclusive results you obtained. Brand and design may matter to some degree, as you say, but, without seeing the "fair" placement, that degree may be more indicative of user error than anything else. You don't place a Forged Friend in a situation where its stem would shear, do you?
edit: I've seen the placement. I dunno, without seeing it with the cam in... ? Thankfully, many have contributed good points about being mindful in placing protection, and, just as positive, the predominant opinion seems seems to be that anybody who'd pass on these "results" at the crag as if they were gospel (it seems like there are a couple - I'm looking at you, evanwish) is being unfair. I believe the larger point isn't to see what's the crappiest placement in which your gear will hold a fall; the point is to place the best gear you can as often as possible. Eventually, you're going to be like Angry and end up doing something like slinging a nalgene bottle as a key part of your anchor, so why not get the best possible placements while the getting is good?
(This post was edited by zeke_sf on Mar 8, 2009, 11:12 AM)
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USnavy
Mar 9, 2009, 2:41 AM
Post #134 of 177
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psprings wrote: Couple questions Navy (I'm not flaming one way or the other, just curious). Were you putting both cams in the same spot? Range-wise, they should both fit in the same placement. Which sort of leads to the fact that appearances can be deceiving. That crack looks good- like a bomber finger lay-back. Is it flaring, parallel? Shallow and bottoms out or deep? I'm guessing it's funky if you had to place the cams in different spots (due to the length/depth difference of OP lobes). What were the lobes of the OP cam like with regards to placement? Was it almost fully retracted? Closer to tipped out? Thanks for this, though. K.I.S.S. (and light) has always been my motto, Metolius 4EVAR! :D
It was fairly parallel but irregular. The crack was deep. The C4 was about 85% cammed and the OP was about 60% cammed through its entire range.
If you look on the previous page you will find some pictures that show the tick marks created by the fall. They will show you exactly where the lobes came into contact with the rock.
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vegastradguy
Mar 9, 2009, 5:21 AM
Post #135 of 177
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USnavy wrote: psprings wrote: Couple questions Navy (I'm not flaming one way or the other, just curious). Were you putting both cams in the same spot? Range-wise, they should both fit in the same placement. Which sort of leads to the fact that appearances can be deceiving. That crack looks good- like a bomber finger lay-back. Is it flaring, parallel? Shallow and bottoms out or deep? I'm guessing it's funky if you had to place the cams in different spots (due to the length/depth difference of OP lobes). What were the lobes of the OP cam like with regards to placement? Was it almost fully retracted? Closer to tipped out? Thanks for this, though. K.I.S.S. (and light) has always been my motto, Metolius 4EVAR! :D It was fairly parallel but irregular. The crack was deep. The C4 was about 85% cammed and the OP was about 60% cammed through its entire range. If you look on the previous page you will find some pictures that show the tick marks created by the fall. They will show you exactly where the lobes came into contact with the rock.
looked for said pictures, just found the two vague pics with the red arrows pointing to a vague spot in the crack where you thought the placement was.
seriously, some close ups and deliberate pictures of the placement, not pictures that might have the placement in them, will go a long way toward getting better feedback from folks.
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USnavy
Mar 9, 2009, 6:04 AM
Post #136 of 177
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vegastradguy wrote: USnavy wrote: psprings wrote: Couple questions Navy (I'm not flaming one way or the other, just curious). Were you putting both cams in the same spot? Range-wise, they should both fit in the same placement. Which sort of leads to the fact that appearances can be deceiving. That crack looks good- like a bomber finger lay-back. Is it flaring, parallel? Shallow and bottoms out or deep? I'm guessing it's funky if you had to place the cams in different spots (due to the length/depth difference of OP lobes). What were the lobes of the OP cam like with regards to placement? Was it almost fully retracted? Closer to tipped out? Thanks for this, though. K.I.S.S. (and light) has always been my motto, Metolius 4EVAR! :D It was fairly parallel but irregular. The crack was deep. The C4 was about 85% cammed and the OP was about 60% cammed through its entire range. If you look on the previous page you will find some pictures that show the tick marks created by the fall. They will show you exactly where the lobes came into contact with the rock. looked for said pictures, just found the two vague pics with the red arrows pointing to a vague spot in the crack where you thought the placement was. seriously, some close ups and deliberate pictures of the placement, not pictures that might have the placement in them, will go a long way toward getting better feedback from folks.
I will take pics of the placement when I go climbing. It rained this weekend and I work during the week.
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evanwish
Mar 9, 2009, 7:37 AM
Post #137 of 177
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it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0
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jt512
Mar 9, 2009, 8:01 AM
Post #138 of 177
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evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0
Another victim of American education.
Jay
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evanwish
Mar 9, 2009, 8:18 AM
Post #139 of 177
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jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay
haa and how's that?
all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up
ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt)
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jt512
Mar 9, 2009, 8:50 AM
Post #140 of 177
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evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt)
Another victim of American education.
Jay
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billcoe_
Mar 9, 2009, 5:13 PM
Post #141 of 177
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jt512 wrote: Another victim of American education. Jay
The real Jay is back! You went to Europe for your education then did you? Congratulations on that.
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billcoe_
Mar 9, 2009, 5:18 PM
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PS, I'd vote this pic most egregiously bolted crack if that was an option.
(PS, Jay, we've seen the granite bolted crack you keep posting, I wouldn't vote for that as the block looks like it would fall off if your cam expanded, so you can save it for someone else. )
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cracklover
Mar 9, 2009, 6:25 PM
Post #143 of 177
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rgold wrote: Someone new to placing gear places two cams, takes moderate falls on them, and one cam pulls. Nothing about this is all that surprising. The fallacy is an implied assumption that the results are explained by the difference in the manufacturer. The same results might have happened if the same make cam was placed twice. Although we can't see the actual placement, we can see the crack just above the placement. [img]http://usera.ImageCave.com/rgold/Technical/Crack.jpg[/img] It is clearly very irregular and seems to be flaring higher up. The rock surface itself also has very thin scaley features, making one wonder whether the surface features inside the crack are analogously questionable. There isn't too much involved in placing a cam in a parallel-sided crack in good rock, but cams in the type of crack pictured here are a very different proposition. All that irregularity means that even micro-movements could change the placement significantly, the short clip-in maximized the chance for such motions, and the potential for surface crumbling adds to the possibility of a lowered coefficient of friction. Under these circumstances, pilot error is a significant possibility, even if the pilot in question is not inexperienced. The disturbing message, and I think there is one, is that cams, fantastic as they are, can be very subtle to place and extremely difficult to judge when the crack geometry is not very uniform.
Excellent synopsis, thanks RG!
GO
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spikeddem
Mar 9, 2009, 7:06 PM
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USnavy wrote: 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.
Edit: This thread is less than useful.
(This post was edited by spikeddem on Mar 9, 2009, 7:59 PM)
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justinboening
Mar 9, 2009, 7:16 PM
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evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt)
It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish.
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evanwish
Mar 9, 2009, 8:16 PM
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justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish.
no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job.
i doubt USnavy was intentionally putting the link cam in a worse position than the C4.
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d0nk3yk0n9
Mar 9, 2009, 8:21 PM
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evanwish wrote: justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish. no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job. i doubt USnavy was intentionally putting the link cam in a worse position than the C4.
The key is (and this is what the guys who've been debating this point with you are trying to say) that the variables that mean that it isn't the same placement could mean that the link cam was in a worse enough placement then the C4 to make a different in the results.
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kachoong
Mar 9, 2009, 8:25 PM
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d0nk3yk0n9 wrote: evanwish wrote: justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish. no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job. i doubt USnavy was intentionally putting the link cam in a worse position than the C4. The key is (and this is what the guys who've been debating this point with you are trying to say) that the variables that mean that it isn't the same placement could mean that the link cam was in a worse enough placement then the C4 to make a different in the results.
Or more clearly, you can have both cams in what you think is exactly the same place and yet gain different results mainly due to factors that you cannot see. This type of "experiment" is so hard to replicate!
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justinboening
Mar 9, 2009, 8:37 PM
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It seems like (or at least from his last post) that evanwish understands that the placements were not equal. What he doesn't understand is that the face the link cam placement was (most likely) not as good as the C4, has nothing to do with the integrity of either device. Instead, it implies that the device was used improperly. I wouldn't blame a massive tricam for failing to hold a fall my reverso would've allowed me to catch (yes, tricams can apparently be used as belay devices), and I wouldn't fault a stopper for not holding in a crack where I was able to win a solid offset nut placement. The cams are different. There is no comparing them in this way (BD 1, Link Cam 0). It's a little absurd to try, and demonstrates a fundamental misunderstanding with what can be expected of equipment.
(This post was edited by justinboening on Mar 10, 2009, 6:12 AM)
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evanwish
Mar 9, 2009, 9:15 PM
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kachoong wrote: d0nk3yk0n9 wrote: evanwish wrote: justinboening wrote: evanwish wrote: jt512 wrote: evanwish wrote: it seems untill we find a placement where the link cam holds and the camalot doesn't, the score is BD=1, OP=0Another victim of American education. Jay haa and how's that? all i'm trying to get at is that for that one particular place for one cam worked over anther. so there's bound to be a placement that ties it up ps: if there isn't i guess we could conclude that link cams suck for other than perfect placements i guess (which i highly doubt) It can't be the SAME placement. That's the issue. There are just far too many variables. You just don't get it, evanwish. no i get the fact that it can neve be the exact place because of head width etc, if you read above i said as close as possible. yes there are a ton of variables, but all i'm trying to get at is that in that specific section of crack, the link cam wasn't the best cam for the job. i doubt USnavy was intentionally putting the link cam in a worse position than the C4. The key is (and this is what the guys who've been debating this point with you are trying to say) that the variables that mean that it isn't the same placement could mean that the link cam was in a worse enough placement then the C4 to make a different in the results. [image]http://fc91.deviantart.com/fs6/i/2005/064/c/0/Beating_A_Dead_Horse_by_livius.gif[/image] Or more clearly, you can have both cams in what you think is exactly the same place and yet gain different results mainly due to factors that you cannot see. This type of "experiment" is so hard to replicate!
haa that is the perfect picture for this.
i understand its not a real "experiment" (and that one would neeed to be done in a pull tester)
we're all getting at the same thing so maybe i'm not putting it into words well:
-BD worked= cool
-OP didn't work= bummer. yes the amount of variables don't allow us to make any conclusions.
i aggree my first post was a bit crude, but i'm just looking at it as in, there are probbably tons of other placements where the results would come out as the exact opposite. (so this one example doesn't mean much at all)
i hope that clears it up.... 
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