squeak-
Assuming the following:
a) The wheels are the same diameter (some bikes, such as racing bikes, have a smaller front wheel to lower wind resistance).
b) The tires are equally inflated and have a similar load on them (also affects diameter).
c) The rider has not “skidded” either tire independent of the other.
d) An excessive number of turns has not been made (when turning a bike, car or other vehicle where the turning wheels are in front, the circumference of the turn is always greater for the front wheels)
e) The odometers are both made for the same diameter tires.
The front wheel will have will still have rolled slightly further, just because of the minute adjustments made by the bike rider in balancing and keeping to the course.