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jafarr
Dec 18, 2002, 8:10 PM
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Ok, I know your thinking..."Not another shoe thread!!!!"
Hear me out. Being an engineer at a company that specializes in rubber compounds, has anyone ever come across actual tests of the different rubbers for shoes?? I don't mean like John Boulderer saying his C4 is the best or Jane Sporty protesting that Fusion is superior. I want real data from tests. Ideally tests from standards; ASTM, ISO?
If not, I will look into it. I need to come up with a Senoir Design Project anyways.
Thanks in advance for the info.
j
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hellbent
Dec 18, 2002, 8:12 PM
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Hey if you do get that info could you post it up here or PM me ?
Want to trace the advances in technology.
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rocknpowda
Dec 18, 2002, 8:13 PM
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One of the climbing mags had a review a few years ago. I don't know how scientific it was, but I think they found relatively little difference in the effectiveness of the different rubbers though some were more durable than others. Check the archives section of climbing and rock and ice.
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jafarr
Dec 18, 2002, 8:16 PM
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Hellbent: I will defintly post my findings, hey why not share the knowledge.
Rocknpowda: Thanks, I was just on my way there, but I'll check both places.
Ok I searched thru their archives. Nothing but the same old thing. All boiled down all the reviews read like this: This shoe works well for me. But, Dave's foot is different than mine, so he doesn't like them.
I was thinking of doing some testing of my own. Hardness, Friction coefficients [--"stickyness", and the such. Anything else I should look into?
j
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epic_ed
Dec 18, 2002, 11:22 PM
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Emperical data? Now there's a concept.
I'd be very interested to know the results of any objective research on this topic. But then again, I'm quite a gear junkie with a lot of time on his hands at work. Dangerous combination...
Ed
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caerbannog_rabbit
Dec 19, 2002, 12:02 AM
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look for the liquid shoe thread.
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dynomaster
Dec 19, 2002, 12:50 AM
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Defentally sounds like you should do it! And defentally post your findings!
Dyno On
Andy
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curt
Dec 19, 2002, 1:18 AM
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I remember the article too, from a few years back. They measured the coefficient of static friction, hardness, etc. for various rubber compounds. As I recall those tested included 5.10, LaSportiva (Vibram),
Scarpa Megabyte (Vibram), and Boreal.
As posted above, the testers found any differences to be quite small. That makes me wonder about the applicability of the methodology used--since 5.10 rubber seems clearly "stickier" to me.
I too think it would be great for some other independent source to do these kinds of tests. You may want to evaluate the new Mad Rock rubber as well. They claim it is as good as 5.10 C4, and from my initial experience with the shoes, this seems to be true.
Curt
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tyraidbp
Dec 19, 2002, 2:11 AM
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Here is the problem with getting this information. It all involves the very important thing called a "trade secret". I can try to pull some strings and see what I can get out of the big two manufacturers(Vibram and Stealth)but I make no gaurantees on that one. I will tell you this, 5.10 developed the new Stealth HF(high friction)and would not even keep any of it in the main office/shop due to fear that someone there would steal it for personal use or gain. With that said, lets see what we can develop.
http://www.tyraid.com
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curt
Dec 19, 2002, 5:44 AM
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There are no trade secrets involved in doing the sort of tests suggested here. All that is required is to obtain representative samples of the competing products and measure the appropriate parameters. I think this is a good idea.
Curt
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jafarr
Dec 19, 2002, 6:20 PM
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ok, I'm going to try to contact the major shoe/rubber companies and try to push the "I'm a poor college student in need of an original project to finally graduate, so give me a sample of your rubber" theme. alright, maybe not that nice, but you get the gist.
I got a slew of ASTM and ISO tests that I can do inhouse at my company, and a couple that I'm going to outsource. If anyone has info or ideas PM me. I'll try to publish a report or something, so then there can be a definitive study.
j
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invicta
Dec 23, 2002, 5:49 PM
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C4 all the way
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rprp
Dec 27, 2002, 2:26 AM
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If you are testing, you might try various temps as well. People have told me that rubber is "best" when this hot or that cold or whatever. But it would be nice to really know.
Also, what about testing some rubber that is a bit worn? It gets those ridges or cracks in it and sometimes I think they roll under and let your foot slip.
Finally, on a flat surface the friction doesn't depend on how much surface area is in contact since big area spreads out and reduces the force. But with all the little bumps and edges on rock, does contact area matter? You always hear people say to maximize contact area, but I bet it matters less than they think.
Looking forward to see what you come up with.
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cruzinsouthoc
Dec 27, 2002, 3:41 AM
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hmm..interesting thread I stumbled onto here. It would be interesting to know what the actual coefficient of friction is between various rubbers and various types of rock. Too bad frictional coefficients depend on both surfaces though. You can't really say that C4 has a frictional coefficient of 0.XX. I guess you can find an average though.
When frictional coefficients are determined...the surfaces of both materials ARE considered. So a steel plate in contact with another plate of the same material will have a certain coefficient, but that same plate on concrete will have a different coeff. because of the concrete surface being rough...same thing with rock and rubber...MAYBE, a matrix can be created where you can cross reference the rubber type with common rock types...ie, C4 has a coeff. of 0.xx on granite and 0.zz on sandstone, etc, etc.
It would be interesting to know how the materials behave at different temps too, but I'm guessing that any testing (and reports thereof) would refer to ambient temperature (~70 degF)...and as for contact area making a difference..who knows, maybe once they start testing, they will find a difference...maybe or maybe not... I can think of one example in the real world where it does - slide plates. Teflon slide plates' coefficient of friction varies depending on the pressure (in PSI). That's found by dividing the weight applied to the plate by the footprint of the plate (contact area). That's probably WAY more detail than this research will ever get into..but maybe someone will run with it.
One last thought...I'm sure that the Tire industry has done some sort of research regarding the performance of their rubber compounds on concrete, asphalt, dirt, etc (at least I hope they have!!)...that'd be a good place to look for some data on how to test climbing rubber.
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granite_grrl
Dec 28, 2002, 4:26 AM
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As far as the tire industry goes, I know that there are various devices to measure road surface friction. I did an instrumentation paper on this, and I can tell you looking this stuff on the internet and then trying to build your own would be interesting. My favorite, and the most feasable to build, was the skid tester. It's a pendulum with rubber on the bottom. When you swing it you lake a look at how far up it swings after brushing the ground, and then figure out how that angle corresponds to friction.
Hmm, it's funny 'cause you never even asked for test procedures or instrumentation. Could you let me know what kind of instumentation that you do use for this, curious for my own intrest.
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