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C4 with kinked stem: still safe?
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By Timothy Mark
Jul 17, 2011
So I've got a nearly-new set of cams (shiny!). Unfortunately, on the first lead with the new rack, my 0.5 C4 was bent where the metal head meets the plastic/wire stem. Since no one fell, I assume this was due to an overenthusiastic follower, but I haven't been able to bend it back straight.

As far as I can tell, none of the metal cables of the stem are harmed, but I can only see a tiny bit of it around the plastic cover.

Is this common? Still safe?

c4 stem #1
c4 stem #1


c4 stem #2
c4 stem #2



c4 stem #3
c4 stem #3

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By Timothy Mark
Jul 17, 2011
One more detailed pic:
c4 stem detail
c4 stem detail

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By caughtinside
From Oakland CA
Jul 17, 2011
That cam is brand new.

Maybe we should have a thread where you post photos of manky wonked out crap that guys still climb on.

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By bevans
Jul 17, 2011
there is nothing wrong with your cam. good to go.

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By Abram Herman
From Golden, CO
Jul 17, 2011
Viking helmet cover, yep.
bevans wrote:
there is nothing wrong with your cam. good to go.


+1

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By sunder
From Alsip, Il
Jul 18, 2011
ICE PIT 2011
Yeah i have 3 or 4 of them like that.

Kinda normal for it to bend like that after a fall on it or it weight in that position for a long time.

There fine

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By Alvaro Arnal
Administrator
From Aspen, CO
Jul 18, 2011
Pup Tent OS
WTF? That's the exact same color scheme I use to mark my gear: Blue with thin yellow on top. And all this time I thought I was being clever and original so no one else would have the same marking...

Oh- and your cam is fine.

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By Marc R
From Boulder, CO
Jul 18, 2011
Dog Safety
Your cam is fine. Don't try to bend it back tho. That will only add to the fatigue of the cable.

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By doligo
Jul 18, 2011
Jose Cuervo Fruitcups dirtbag style
SkiNowWorkLater wrote:
WTF? That's the exact same color scheme I use to mark my gear: Blue with thin yellow on top. And all this time I thought I was being clever and original so no one else would have the same marking...


I once climbed with a guy who had identical gear to mine that was marked exactly the same way! Our draws were the same Mammut dyneema slings with Mad Rock wiregates and all our hardware was marked with pink and navy blue strips of nailpolish. And I thought I was being clever and unique...

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By Auto-X Fil
From NEPA and Upper Jay, NY
Jul 18, 2011
Totally normal. All my cams look like that after doing aid in horizontals...

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By Daryl Allan
From Sierra Vista, AZ
Jul 18, 2011
Me and my Fetish I guess.. ;)
caughtinside wrote:
That cam is brand new. Maybe we should have a thread where you post photos of manky wonked out crap that guys still climb on.

No doubt... that would be a great thread to see.

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By sunder
From Alsip, Il
Jul 19, 2011
ICE PIT 2011
Everyone should share pictures of there manky ass cams with bent stems deformed lobes. Unfortanlly my cams havent been destoryed or manked so i can only posted pictures i found on the interweb.























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By Daryl Allan
From Sierra Vista, AZ
Jul 19, 2011
Me and my Fetish I guess.. ;)
!!!!!!!!! I would love to hear the story behind that obliterated #2 six photos down. Holy lobe-ripper, Batman!

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By John R. Williams
From Fort Collins, CO
Jul 19, 2011
Coming up the lower section in deep snow.
Daryl Allan wrote:
!!!!!!!!! I would love to hear the story behind that obliterated #2 six photos down. Holy lobe-ripper, Batman!


Hell yes! a blue whale took a lead fall on that #2. I'd still use it....

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By sunder
From Alsip, Il
Jul 19, 2011
ICE PIT 2011
John R. Williams wrote:
Hell yes! a blue whale took a lead fall on that #2. I'd still use it....


Works great as a NUT!!

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By Matt J
From Bozeman, Montana
Jul 20, 2011
How convenient, I was just going to ask the same question.

I dropped this near new cam down a 200ft slab, it bounced around alot and landed in the dirt.

I'm sure it should be retired, I hear cams get micro cracks and can just snap at any moment?

Other than the obvious, there is no other visual damage, it still operates as smooth as it was before. It looks like one of the axles was bent/stretched. There is some play between the lobes but everything seems to be intact.

What do ya'll think?


c4 canked!
c4 canked!

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By Bud Martin
From Bozeman, MT
Jul 20, 2011
I saw a guy do a very similar thing as the #2 to a BD #3, he took a 15-20 footer off of the 5.9 pitch of Reed's Pinnacle Direct and seriously mangled the cam though it did hold the fall. I went up latter and couldn't get the thing to budge, would have needed a rock or a hammer to get the thing out.

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By sunder
From Alsip, Il
Jul 20, 2011
ICE PIT 2011
Matt J wrote:
How convenient, I was just going to ask the same question. I dropped this near new cam down a 200ft slab, it bounced around alot and landed in the dirt. I'm sure it should be retired, I hear cams get micro cracks and can just snap at any moment? Other than the obvious, there is no other visual damage, it still operates as smooth as it was before. It looks like one of the axles was bent/stretched. There is some play between the lobes but everything seems to be intact. What do ya'll think?


The Axles on the cams float, to compensate for cam rotating during a fall, or something like that. If you lay the cam sideways and push on the higher axel it should even it out. you may need to use a hammer and a block of wood to get it flat again.

I have 3 thoughs on this.
1. Personally i would not climb on this cam.
2. If climber gear will break that easily we would all be dead right now.
3. Its kind of like climbing on aliens you never know if its going to blow apart

Ultimatly it will be up to you to dieciede if you want to retire the gear or climb on it.

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By Ray Pinpillage
From West Egg
Jul 20, 2011
Middle
"Micro cracks" = mental retardation

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By Aric Datesman
Jul 20, 2011
Have to object to the pic of the RE Durango being in the list of mangled cams (5th one down), as I had replaced the lobes with a new design I was working on at the time and failure of the stem came a good bit above rating (~15kN or so, IIRC). Not sure if the U-stem Camalot pic is one of mine or not, but won't complain since I'm of the opinion BD should do a general recall/stop use on them due to an inherent design flaw that allows them to pull out well below rating when placed above 50% expansion.

-a.

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By Sam Stephens
Jul 20, 2011
Top half of Melifluous
Ray Pinpillage wrote:
"Micro cracks" = mental retardation


This.

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By Abram Herman
From Golden, CO
Jul 20, 2011
Viking helmet cover, yep.
Aric Datesman wrote:
I'm of the opinion BD should do a general recall/stop use on [Camalots] due to an inherent design flaw that allows them to pull out well below rating when placed above 50% expansion. -a.


Could you elaborate on that? What would make them more likely to fail under their rated strength than any other cam?

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By Aric Datesman
Jul 21, 2011
@Abram- Don't want to drift the thread too much, but in a nutshell there is enough clearance between the axles and the arc cut into the opposing lobes that when loaded the axles begin to bend and the outward force is reduced. This problem is compounded if the lobes are expanded enough to reach the divot cut into the axle clearance arc, which allows the axles to bend significantly and pull out well under rating. The one in the pics below took 4 attempts to get it to stick in the test fixture on account of the bending allowing individual lobes to slip and twist the cam into all sorts of uneven placements, and when I finally got it to stay in properly all it did was 9.15kN as the lobes pushed the axles U-shaped as they rotated to their full expansion and tipped out (at which point it slipped out of the fixture. Mind you, the cam was rated at 12kN. I did a couple more of them as well, and all of them did the same thing. I have video of it squirreled away somewhere that clearly shows the problem, so I'll post a link if I can find where I archived it.

BTW, this issue was corrected in the single stem Pre-C4 Camalots that replaced the U-stem ones, as the axles in the single stem ones are constant diameter and bear directly on the opposing lobe to give more support and are therefore more resistant to bending like the U-stem axles.

Pic of a Green U-stem Camalot after slipping from the fixture:
Green U-stem Camalot after slipping from the test ...
Green U-stem Camalot after slipping from the test fixture


Pic of the deformed axles:
Deformed axles from Green U-stem Camalot that slip...
Deformed axles from Green U-stem Camalot that slipped from the test fixture


Pic showing the space between the lobe and opposing axle:
Pic showing the clearance between the axle and lob...
Pic showing the clearance between the axle and lobe in a Green U-stem Camalot


Pic showing just how large the divot is (keep in mind that it's the _small_ diameter of the opposing axle that would bear on theedge of the slot, not the _large_ diameter):
Pic showing the size of the assembly divot on a Gr...
Pic showing the size of the assembly divot on a Green U-stem Camalot

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By Aric Datesman
Jul 22, 2011
@Abram- Found the video and tossed it up on YouTube for you. It's painfully obvious what's happening as the test progresses, and is why I think BD should recall them.


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By Steve86
Jul 22, 2011
@Aric

Yikes, that's pretty scary. Thanks for posting the video, makes the failure mode a lot more obvious.

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By Aric Datesman
Jul 22, 2011
Steve86 wrote:
Yikes, that's pretty scary. Thanks for posting the video, makes the failure mode a lot more obvious.



That it does. Sadly the only response I got from BD was a rather heated discussion with Russ Clune at the NRR a few years back, who was none too happy about me having the remains of the cams and an explanation of how and why they failed on display. He was of the opinion the tests were invalid because the cams being tested were used and had an unknown history, while I see them as good sample of what's currently out in the field (especially when the failure stems from a rather obvious design flaw). We ultimately agreed to disagree and I was asked a short while later to remove all of the BD gear from the display. BTW, when I first posted this on RC ages ago I stopped short of calling it a design flaw mostly due to not wanting to make trouble for the folks at BD. The discussion with Russ left a bad taste in my mouth WRT BD, hence my taking a harder stance nowadays.

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