I know that shoe rubber is hardly a safety issue, but people seem so bent on their preferred shoe, dismissing all others, that I thought I’d post this up for some scientific critique. I came across this page on testing Spadout did on rubber from various shoe companies. Hardly extensive or well-rounded, it mainly comprised of comparing the static coefficient of friction for various rubbers. Typical weight on rubber on inclined plane deal.

http://www.spadout.com/r/climbing-rubber-test/

Some obvious issues I saw was the light weight used. I’d guess this would significantly favor softer rubbers. The temperature was held constant, and I know companies target an optimal temp, which could be different from company to company. There was also a minimum of different surfaces and contours tested.

Additionally, this doesn’t even touch on shoes, simply the rubber. It just caught my eye because I hear so much negative talk about Evolv rubber from 5.10 die hards, and here they are as the ‘stickiest’ in this particular test.

The weight (15 oz of steel)

Clicky!

Oh, and thx... I'd been contemplating doing something similar and you've gotten me off the hook for it!

Some obvious issues I saw was the light weight used. I’d guess this would significantly favor softer rubbers.

Wow thats it, just seems like that wouldn't give you the best test results. But it was a constant so i guess that works.

My thought was sort of the opposite - I was thinking a heavier weight might favor softer rubbers, since they are more prone to deform. I guess it depends on how soft "soft" is.

My other thought was that this isn't terribly applicable to climbing performance. Friction is, no matter what they taught you in high school, a lot more complicated than F = mu*N. In fact, that silly "independent of surface area" nonsense breaks down in all but the simplest cases, and even breaks down in those simplest cases sometimes (I ran into this one a few years ago when I was TAing undergrad labs). So looking at the point where a chunk of rubber starts to slide on a smooth surface is, IMHO, not very useful. It's telling you nothing about how that rubber would stick to actual, featured rock.

In my limited personal experience, "softer" rubbers tend to be stickier from a smearing perspective, because they can deform more to the contours of the stone, putting more surface area in contact. The tests seem to show the exact opposite of my personal experience with Vibram vs. Stealth C4, where I found Vibram to be absolutely lousy at smearing compared to the Stealth.

I'm honestly a bit disappointed to see this study coming from a physicist - I would expect there to be more "caveats" included by a serious scientist. I suppose it could also be the editing of Spadout to remove what they deem to be unneeded complications.

I know that shoe rubber is hardly a safety issue, but people seem so bent on their preferred shoe, dismissing all others, that I thought I’d post this up for some scientific critique. I came across this page on testing Spadout did on rubber from various shoe companies. Hardly extensive or well-rounded, it mainly comprised of comparing the static coefficient of friction for various rubbers. Typical weight on rubber on inclined plane deal.

http://www.spadout.com/r/climbing-rubber-test/

Some obvious issues I saw was the light weight used. I’d guess this would significantly favor softer rubbers. The temperature was held constant, and I know companies target an optimal temp, which could be different from company to company. There was also a minimum of different surfaces and contours tested.

Additionally, this doesn’t even touch on shoes, simply the rubber. It just caught my eye because I hear so much negative talk about Evolv rubber from 5.10 die hards, and here they are as the ‘stickiest’ in this particular test.

The only thing I can think of that this test applies to is on steep face moves where you have all your weight on your hands and are desperately counting on tiny friction from one foot to keep you from barndooring.