[Jay TenBrink]

[quote=JVN]As you move the wheel from "fast" mode to "torque" mode, do you believe the frictional load caused by sliding the sphere sideways on the carpet will cause issue?

John,

I think the bigger challenge to overcome would be the losses from scuffing while going straight. The contact patch where the tire meets the carpet would approximate a section of a cone. This conic section will want to turn about a point at the apex of this cone. Just think of how a styrofoam cup rolls in a circle. Car tires will do the same thing and can cause your vehicle to pull yo one side if they have excessive conicity, which is one side larger than the other.

Assuming the conicity of the tires would all point in (or out), the forces would cancel each other out. There would still be high rolling resistance to overcome.
Sounds like an interesting idea.

Jay