My car tire impressions- for real

[upside22]

I suspect that the issue here is a little more complicated than has been presented. The normal force at any point on the surface of a tire is going to be inversely related to the total weight of the bike and the contact area. Thus the bigger the contact area the lower the normal force at any point in the contact area. This is why they use big tracks to hold up an M1A1 tank instead of round wheels - bigger surface area results in less normal force at any specific contact point.

The force being applied to the tire also gets spread out over the same contact area. It doesn't matter if this is torque applied by the engine or centripetal force from going around a corner.

Where this gets complicated is that the total action between a tire and the surface is going to be a statistical relation integrated over the entire contact patch, i.e. at any instant of time one point on the contact patch may have the friction force exceeded while another point does not. I suspect what a rigorous statistical analysis would show is that the larger the contact patch the higher the total torque has to be to exceed the total friction force.

If this was *NOT* the case then it would make more sense to run racing bicycle tires on our motorcycles in order to reduce rolling friction since the same friction force would be available to hold the motorcycle to the road regardless of the size of the contact patch.