Lets say theyre for making an attempt at grip. It can spin them with no effort at all, but they still make a lot of forward thrust when theyre spinning. Its fast when it manages to stay on the ground, it tends to wheelie up on one wheel and start cart wheeling. I think I need a wider wheelie bar. I want to try maxx sized foam tires, but Im afraid it would eat through them too quickly, and they would get expensive.