Coefficients of Friction

[sanddrag]

With 1.125" wide wedgetop, 4 wheels contacting the ground, we obtained a COF of about 1.1 by using a cheap bathroom scale and pushing against a wall at full force on carpet quite similar but not identical. For Skyway beadlocks (8x2) turned down flat, we obtained approximately .9 from what I can remember, but that was with a (approximately) 90lb robot. The colson wheels have a lower COF than the wedgetop tread.

Width does have something to do with it on carpet. I saw teams with .75" wide wedgetop tread get pushed around. But I don't think you need to go to 2" wide to get more traction. I'd say 1.25" is about the absolute max you need to go with wedgetop. There is a region where more width will give you more traction but there is a point where all more width does is take up more space.