Originally Posted by
Toddorado
If you think about it (not to come off like Cliff Clavin - oops, too late), let's say you're in x gear. No matter what size your tire, the distance travelled in one revolution of the crank will be the same. A smaller tire will advance y inches/centimeters/what have you, the larger tire will go the same distance, with a little left over. Think of it if you unroll the wheel into a straight line - helps visualize it.
Huh? If I am reading you correctly, you are saying that one the same bike and in the same gears, you will travel the same distance per crank revolution no matter the tire size?
If this is the case, then no that is not correct. For simplicity sake, let's say the chainring and the rear cog are of equal size. Then one revolution of the crank will be one revolution of the wheel. Let's just say the tires in question have a diameter of 27" and 26", then the distance traveled will be 3.14 x 27= 82.78" and 3.14 x 26= 81.64", slightly more than 1".