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Good (safe) 24s at Arapiles |
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15-Nov-2011 5:05:46 PM
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Goodbye is way harder than Downwind! Did Col originally grade that 15?
And Neil - where did you rip the link cam from? I'm beginning to think you have a problem with link cams. I'm going to have to blame you for the problem, because otherwise I'd have to question my undying love of link cams.
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15-Nov-2011 5:19:01 PM
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Surely John Smart graded downwind, not col? In any case its not a sandbag. Its only tough if you can't keep your head together.
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15-Nov-2011 6:17:20 PM
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On 15/11/2011 Wendy wrote:
>And Neil - where did you rip the link cam from? I'm beginning to think
>you have a problem with link cams. I'm going to have to blame you for
>the problem, because otherwise I'd have to question my undying love of
>link cams.
It was a purple link cam pulled to the smallest size. It was deep inside the most bomber of bomber placements just above the big pocket/hand jam middle rest stance. It held my weight briefly then stripped clean out. I just don't trust most cams these days.
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16-Nov-2011 10:28:24 AM
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On 15/11/2011 nmonteith wrote:
>It was a purple link cam pulled to the smallest size. It was deep inside
>the most bomber of bomber placements just above the big pocket/hand jam
>middle rest stance. It held my weight briefly then stripped clean out.
Stripped during a fall, or stripped while moving about a lot while hanging around on it?
>I just don't trust most cams these days.
Hmm.
You will end up going to slung machine nuts and pebbles at this rate, as by my count (from your posts over the years), the semi-passive tricams, and now 'most cams', are off your list!
Heh, heh, heh.
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16-Nov-2011 10:46:08 AM
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On 16/11/2011 IdratherbeclimbingM9 wrote:
>Stripped during a fall, or stripped while moving about a lot while hanging
>around on it?
I had rested on it - then got off the rope to attempt the move again, fell off and it popped clean out. Lucky for me I'd placed a backup wire 2 feet below it when hanging. Otherwise I'd probably have two broken ankles now. The cam was shoved in pretty tight and I highly doubt it would have moved when I unweighted it. I just think the force of a fall was more than the just hanging off it.
These days I just don't trust single bits of trad full stop - no matter what they are. I always double up if I can hit the ground. I've had wire cables break, cam lobes snap, bomber looking gear slip out of smooth rock....
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16-Nov-2011 10:59:05 AM
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It is hard to imagine why it came out given your description, and I am surprised by it doing so. Even overly compressed in smoothish rock, wouldn't have been enough to strip I would have thought, unless some torqueing action was also involved, or the rock was highly polished.
I shall be more circumspect in my useage of my link-cams as a result, though I don't have the smallest two sizes, and am increasingly reluctant to obtain them now!
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16-Nov-2011 11:02:40 AM
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On 16/11/2011 IdratherbeclimbingM9 wrote:
>Even overly compressed in smoothish rock, wouldn't
>have been enough to strip I would have thought, unless some torqueing action
>was also involved, or the rock was highly polished.
Maybe a few degrees of torque in the placement - and the rock was certainly highly polished!
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16-Nov-2011 11:10:04 AM
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I should say I've had the most bomber of bomber looking hand crack size cam strip out of a perfect parallel crack in Yosemite once on aid. I couldn't believe it stripped - it was my thank god piece after 10m of shitty copperheads. The rock was very smooth and i suspect it just tracked down. Lucky for me one of the copperheads actually held a lead fall!
It was a two pronged sword - I suddenly got renewed faith in copperheads - and lost faith in cams.
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16-Nov-2011 11:55:18 AM
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Cams need some outward pressure from the springs to work properly, were the springs in the cams still effective or were the axles gummed up?
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16-Nov-2011 12:14:45 PM
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On 16/11/2011 Hendo wrote:
>Cams need some outward pressure from the springs to work properly, were
>the springs in the cams still effective or were the axles gummed up?
Certainly the springs were working fully on the linkcam. Not sure about the mystery Yosemite cam.
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16-Nov-2011 12:54:54 PM
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On 16/11/2011 Hendo wrote:
>Cams need some outward pressure from the springs to work properly, were
>the springs in the cams still effective or were the axles gummed up?
I don't think this is true. The friction force against the rock is a function of the cam lobe angle, and the tensile force acting on the stem. The spring forces would be far smaller by comparsion, and I would think negligible in this consideration.
More geeky math available all over the internerd, including
http://en.wikipedia.org/wiki/Spring-loaded_camming_device.
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16-Nov-2011 1:23:10 PM
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On 16/11/2011 nmonteith wrote:
>On 16/11/2011 Hendo wrote:
>>Cams need some outward pressure from the springs to work properly, were
>>the springs in the cams still effective or were the axles gummed up?
>
>Certainly the springs were working fully on the linkcam. Not sure about
>the mystery Yosemite cam.
I was wondering whether it was something to do with the link cam? Would be interesting to know whether another design would've held. This of course doesn't help with the yosemite cam.
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16-Nov-2011 5:03:11 PM
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On 16/11/2011 IdratherbeclimbingM9 wrote:
Even overly compressed in smoothish rock, wouldn't
>have been enough to strip I would have thought, unless some torqueing action
>was also involved, or the rock was highly polished.
compression doesn't affect holding power (but you may not be able to remove them)
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16-Nov-2011 5:05:06 PM
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On 16/11/2011 NMcKinnon wrote:
>On 16/11/2011 Hendo wrote:
>>Cams need some outward pressure from the springs to work properly, were
>>the springs in the cams still effective or were the axles gummed up?
>
>I don't think this is true. The friction force against the rock is a function
>of the cam lobe angle, and the tensile force acting on the stem. The spring
>forces would be far smaller by comparsion, and I would think negligible
>in this consideration.
Not entirely true. They need spring force to initiate all this. The classic failure is with 'sticky' cams and a sudden force. They never get a chance to behave like cams.
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16-Nov-2011 11:22:43 PM
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Chance of the cam walking would also increase if the springs are bad.
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