Testing out some rubbers!

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Testing out some rubbers!

Postby *Chris* » Mon Nov 24, 2008 8:51 am

Fooled you. Well kinda. Somebody did a pretty cool test of the most common climbing shoe rubber formulas. The results were not what I would have expected.

p.s. If you were hoping for info on 'personal' rubbers. I'm sure the interweb has info on that too.
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Re: Testing out some rubbers!

Postby granite_grrl » Mon Nov 24, 2008 9:59 am

Cool, thanks for sharing. The different between the Madrock rubber performed on plastic vs rock was probobly the most surprizing to me.

I wonder how different the results would be in different temps too. There's a lot of variables at play there.
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Re: Testing out some rubbers!

Postby Adam » Mon Nov 24, 2008 3:58 pm

wow i'm surprised c4 does so poorly. but i do agree the evolve rubber is uber-sticky... my only pair were awesome, but wore through very quickly.
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Re: Testing out some rubbers!

Postby chossmonkey » Mon Nov 24, 2008 8:58 pm

I haven't tried the newest Evolve rubber but I found the older stuff to not be quite as good as C4. It was really close though. I wouldn't be surprised if it was better now.


That test doesn't really reflect real life climbing. There is much more to how well rubber sticks than what that test could do.
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Re: Testing out some rubbers!

Postby *Chris* » Tue Nov 25, 2008 8:34 am

I don't know... that test is a pretty standard way for determining the friction (stickyness) between two surfaces. I'd say it's a pretty compelling test (especially given the wide spread in the results). I agree that there's way more to a shoe than the stickyness of the rubber though.
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Re: Testing out some rubbers!

Postby betaburgler » Tue Dec 23, 2008 11:04 pm

The problem with rubbers in general is that they can have wildly varying properties at different temperatures which would directly affect their coefficient of friction. I definitely think the test should be repeated at a minimum of two other temperatures to be more complete.

I also believe the weight used is misleading. 15oz per 4 inches squared is roughly 1/4 pound per square inch. No real situation will ever involve weights so low. With such a low weight softer rubbers will deform disproportionately more, and so have more contact area with the surface. Under the weight of a human being the harder rubbers would "catch up" with the softer rubbers as far as surface area contributions are concerned. The other part of this is that rubber is so readily deformable that it mimic the surface characteristics of the surface it is pressed against (effectively increasing its own surface roughness which will directly affect coefficient of friction). Softer rubbers will of course better mimic at lower applied forces.

I also think the surface of the granite could have better resembled what is encountered when climbing. That was a cut piece of granite. It had a relatively smooth surface compared to the surface of outdoor granite which is very textured.
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