[sanddrag]

I've always wondered about the traction of a larger diameter wheel compared to a smaller diameter wheel of the same width. I'd speculate it is more, since the curvature of the wheel approaches a straight line as the diameter approaches infinity. On squishy surfaces such as rubber and carpet, I can definitely see this making a difference.

It would be cool if AndyMark and VEX would step up to the plate to put this debate to rest once and for all, with some real scientific testing and published results

In the end though, the real limiting factor in pushing is the internal resistance of the battery.