> Looking at a different example...how does a bike weighing say, 25 lbs, > having 2 tires pumped up to 90psi exert 180psi on 2 little contact > patches where the rubber meets the ground? At 90 psi those tires are > gonna be firm with very little contact patch. > 'cause each wheel only needs 1/2 of a square inch to support a 180# man. Steve