New Study: Which Shoe Rubber is Stickiest?

Which climbing shoe rubber is the stickiest? Climbers have been debating that question for the past 40 years when the first smooth soled climbing shoes migrated from Europe to the United States. We climbers wear specialized shoes to increase our climbing performance and the rubber on the soles of those shoes can directly impact that performance. Sticky rubber helps us stick to the rock better, allowing us to climb harder and higher. The rubber you put on your feet directly translates to how hard you can climb.

For the past 40 years, the question of sticky rubber has been a debate because little empirical data exists that compares the various shoe rubbers. Now, however, the debate is over. A study, published by Spadout.com and conducted by climber and physicist Steven Won at Northwestern University's Department of Physics and Astronomy, analyzes all nine popular climbing rubbers. Climbing shoes with each rubber were purchased and cut apart, with a sample piece of rubber used to test its “coefficient of friction” on both a granite hold and artificial hold.

The results are surprising. I haven’t climbed on every type of rubber. Like most climbers, I find a rubber that works for me and then I have all my resoles done with that rubber. The study’s overall winner was Evolv TRAX XT-5 with La Sportiva’s FriXion RS the runner-up. The 5.10 Stealth C4 rubber that I’ve always used came next to last, just above Mad Rock’s Formula #5. My climbing partner Brian Shelton with Front Range Climbing Company isn’t surprised, “I’ve always used my Evolv shoes on my hardest face routes cause they’re the stickiest.” I might have to switch over and see if a new rubber helps me climb harder.

Remember, of course, that this study is a first step in determining what are the best rubbers. The study was done in a lab with controlled temperatures and a limited load on the rubber samples. Further testing needs to be done in “real world” conditions. Check out the complete Climbing Rubber Test study, including the methodology, how the tests were performed, the physics behind the test, and the mathematical Coefficient of Friction formula, at Spadout.com.

What do you think is the stickiest rubber? What kind of rubber do you resole your rock shoes with? Does rubber make a difference? Is this study accurate? Does a study done in a lab translate to the real world of rock and climbing? Let me know your thoughts about climbing rubber and what you use at the Climbing Forum.

Learn more about rock shoes:
Which Rock Shoes Should I wear
10 Tips on Buying Rock Shoes
Taking Care of Rock Shoes
Resoling Your Rock Shoes

Photo above: Which sticky rubber makes you climb better?
Photograph © Stewart M. Green