Originally Posted by
lindafranc
I recently changed from 700 x 35 mm semi-slicks to 700 x 41 (or so) heavy treaded tires. I initially found the new tires much harder to pedal, maybe like 30 to 40% harder. It was kind of like lifting weights, not huffing and puffing. My legs kind of burned and it was not fun going up hills.
Then I checked the tire pressure and it was 25! So I pumped them up to near 80 (the max indicated on the tire) and they now feel only slightly harder to pedal than the 35 mm semi-slicks. I have only went on three 4 mile rides so I don't know for sure if it is in fact true. Has anyone experienced this? Does tire pressure make a major difference?
Tricky question. A tire that is too hard will bang into and then roll over a smaller stone rather than slightly engulf the stone for a second as it rolls by. Too soft and you are losing energy that you are pumping into the crank. Rolling resistance can be a fickle bi.... pregnant dog. Not only can pressure affect rolling resistance but also traction, tire wear, handling, and rider comfort. If all you are worried about is wasted energy or absorbed energy then stick with the tires at max pressure unless you are riding on snow.