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Chockstone Forum - Gear Lust / Lost & Found

Rave About Your Rack Please do not post retail SPAM.

research papers on passive pro
12:00:14 AM
mikl law
1:22:16 AM
No money in it so no real research, what little has been done would be proprietry. I assume they got horifyingly low numbers out of poor placements and realised it's only rope stretch that keeps us all from dying.

8:33:01 AM
nuts themselves have been tested (they don't just make up the Kn figure) but placements are up to you.
I've gotten more and more nervous climbing with Jeff, who lets me know how dodgy so many of my placements are. I also like to think that my placements are getting better.
11:32:46 AM
Are you just using google, or are you searching a journal database? If you're looking for papers a journal database will be much more fruitful. You should be able to get some kind of access through a university library website, although I don't know how much access they give to non-students/staff. Good luck anyway.

12:11:05 PM
yeah i think mikl is right, there's no real reason why anyone would have done research on this except for teh companies that make the nuts,and they would be very unlikely to release that information to the public. not because they're hiding anything but thats how proprietary research works. they've got to protect their products and all the stuff they've learnt about making them. i don't think a company would be too open to someone asking for info about flaws in their product designs unless they had good reason (esp when it relates to possible fatal accidents), but you could always try..

of course its possible there's someone out there who's done decent studies in the public domain (eg along the lines of stephen hawkshaw's (sp?) research in bolting in sandstone at usyd), but good luck..

12:34:51 PM
I will attempt to explain what I think mikl was referring to.

The 'impulse' of an action is the force (F) applied multiplied by the time it is applied for. When you fall on the end of a rope, a fixed amount of impulse is required to make you stop. Call this impulse X.

If you have a rope without any stretch at all, the equation:
Impulse = Force x time
X = (large force) x (small time)
since you will stop very quickly.

On the other hand if you have some stretch (e.g. dynamic rope), the equation becomes:
X = (small force) x (large time)

The higher force applied when there is no rope stretch has four results:
1) The climber will have a broken back due to the larger stopping force
2) The rope is more likely to break due to the larger tension forces on it
3) If the rope doesn't break, the gear is more likely to pull due to the higher force on it
4) If the gear doesn't pull, the rock is more likely to fail due to the higher force on it

I hope this made sense.

This is why we don't climb on static ropes.

12:43:03 PM
On 5/04/2005 ti wrote:
>... Hmmm, a journal database. That could be quite helpful. Thanks! There's
>such a plethora of research to do...

A uni library search is good, but you could also try Google Scholar ....pretty extensive search engine for journals and scientific papers/articles - an alternative if you can't access those subscriber-only databases.
12:49:40 PM
Hi Ti,

Can't help you much on the passive pro question, but if you are doing a project that requires a sacrificial cam or biner I can donate some stuff that got dropped and which I have declared unsafe for climbing. Would be fine to tear apart to get an understanding of how cams work etc though....

Let me know if you want them and I'll bring them into the gym for you.


1:35:54 PM
On 5/04/2005 climbingjac wrote:
>I can donate some stuff
>that got dropped and which I have declared unsafe for climbing. Would
>be fine to tear apart to get an understanding of how cams work etc though....

Give it to me Jaq!! Booty... i also have have plenty of REALLY old bad cams at home that you could use.

1:55:42 PM
On 5/04/2005 ti wrote:
>A more poignant question that I should be asking is: What does everyone
>think of passive pro? What are people's perceived pros and cons of using

a well placed nut is usually stronger than a cam, assuming good rock.
(no moving parts, no walking, no tiny axle) (ckeck the Kn rating on your gear.)
DMM "Wallnuts" Size 10 (12kN)
Black Diamond "Micro Cam" Size .1 (7kN) Range 8.6 to 13.7mm
cams are only really useful when a nut can't be placed (parallel cracks)
or when you're feeling pumped and panicky.

my personal feeling is that usually, the smaller the crack (within reason) the better the pro.
mikl law
11:33:41 PM
Hi Mikl, thanks for the reply.

When you wrote '...they got horifyingly low numbers out of poor placements and realised it's only rope stretch that keeps us all from dying.' Are you saying that nuts are an ineffective, possibly even useless, means of protection?

Nuts are strong in good placements and bad in bad ones, that variability is hardto assess fully even for experienced nut fondlers.

If you want a nice project- Update tricams.
There are a few things you could do, redesign them based on modern thin tapes (spectra etc) for the smaller sizes. This would make them a lot narrower and less clunky. You could reduce the weight by FEA analysis and CNC machining to reduce the fat, or by casting in magnesium (see woodstock magnesium technologies).

The larger sizes could have the Mg/ Ti and FEA treatment too. A change in cam angles might be feasible, and the ability to stack them to make a super tricam capable of filling small chimneys are all possible and easy too.

Phil Box
10:37:12 AM
I`ll second the update design for tricams. That to my mind would be a worthwhile process.
11:12:35 AM
What about checking the people who set the standards? Like CEN, they must have some methodologies to create some sort of uniformity when testing the stuff.

4:27:57 PM
is everyone clear about which kind of tricam?
i assume mikl is talking about the lowe/camp (passive) kind.
which are a great idea that definitely needs a little tune up.

(the metolius (SLCD) kind i only ever had one of and left it on Bastion Buttress in a frenzy of paranoid downclimbing.)

thought i'd cancelled the previous 'nut v cam strength' post.
changed my mind after a bit of research.
12:30:38 PM
On 6/04/2005 ti wrote:
>What does the acronym CEN stand for?

Comite de Europeen Normalisation (or something similar) who have taken over from the UIAA for setting the standards for climbing equipment in Europe. Their index is found at

I have a feeling that it will take a bit of navigating as well.

There are 15 messages in this topic.


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