[sanddrag]

Traction can go both ways with surface area. Rock crawler 4x4s (and sand vehicles) air down their tires for a bigger footprint. More suface area and more traction. But some 4x4 mudders (and snow vehicles) use really skinny tires so they can sink into it and get a bit on what's on the bottom rather than float over on top. I know this isn't really about traction on FIRST robots but it was the first example I could think of. There are just so many variables involved that it really depends on the exact materials and the exact situation.

Traction is such a complex issue that it's really not worth debating about because everyone is right and wrong, just in different ways. There are so many factors involved: tread, interlocking surfaces, surface area, friction, composition of both tractive surfaces, stickyness, softness of both surfaces, gravity, and that's just the beginning of them. Nascars have smooth tires on a very smooth surface but get incredibly good traction. 4x4s have very aggressively treaded tires on very uneven surfaces but get incredibly good traction. There is a different kind of tractive surface that works best for every terrain. And it being the best is only in the eyes of the operator. There are way too many things that make up traction for any one person to be right about what works the best for everyone. Just do what you think works good and let everybody else do what they think works good.

Problem solved.