[j-c-c]

Originally Posted by Isaac Zachary

My take on it is this:

1. You have a twisting force that causes the side walls to flex.
2. At the same time you have more downforce due to inertial forces caused by acceleration, which makes the tires squat.
3. Does this really reduce the radius and thus increase torque? Of this I'm not certain, as with every turn of the wheel the outer circumfrence of the tire does not change and therefore you get generally the same distance per turn with or without the sidewall flex.
4. We are dealing with flexible structures here (tires) and trying to apply the math that applies to solid ones (force x radius). But maybe it's more like a pulley (small diameter wheel pulling on larger diameter wheel).

on #2, the only dim I see pertinent is the rolling radius, the free tread radius not in contact with the ground has only aero effects and maybe some inertia effects as it recontacts the ground, and maybe as some stored energy being at a larger radius traveling at a faster rotational speed?