[ASV]

the distance between the center of the wheel and the top of the pavement
is your effective radius
geometry will not allow for anything else
without spinning the tire on the rim

part of the tire is however behaving as pavement and causing some confusion

so to clear it up the flex point of the sidewall the invisible point inside the tread that acts as the hinge that point is the difference between the wheel and and the " tank tread "