I am surptised it is that much. It may or not equate to that difference of "Rolling Diameter" I may play around with this a bit. Thanks for the information.....good job.
Well if you do the math....the fact that it rises and presuming it stays raised as the wheels turn the effective circumference will be effectively the calculated value done by the OPExactly. The circumferential length of the tread does not change to any significant degree.