gregk wrote:
Which one do you think will be easier to deform by pressing it with your thumb? The racing tire, of course. Now think of the road as your thumb, and repeat the process at 25mph for an hour… all of a sudden that extra resistance adds up.That doesn't explain the full picture. You can cause a stiff slow tire to give way to your thumb just as far as a supple tire by pumping it to a lower pressure, yet this causes hysteresis losses to go up.
When two tires are pumped to similar thumb-squishiness, the thing that makes the supple tire faster is that less of the deformation is taken up by lossy tire elements, and more energy gets returned to forward motion when the tire rebounds.