...And the difference is grand 3.5%. Wow. Tire widths are all over the chart, there are 28s that are closer to 25s than some 25s, and vice versa. With MTB tires the difference is even more pronounced - pump it up from 50 to 65 PSI and watch it swell... Even using Hot Potato's method of computer calibration your ride distance recorded will be affected by the difference between pressure at calibration and pressure during ride.
This is precisely the reason I tell my distances as "about xx miles".
I guess, in your case the tire is a bit narrower than nominal size so the wheel rotates a bit faster to cover the same distance.
Geez, listen to me reveling in my geekitude....
Have fun and ride safe
SF
Last edited by sci_femme; 09-21-09 at 08:47 AM.
Reason: typo