Originally Posted by
Miele Man
I have pretty narrow 26" rims on my MTB that is converted to a dropbar bike. When I switch out the 2.125 tries for smooth 1.25 tires I notice a HUGE difference in ease of pedaling with the narrow tires. In fact when I had 42 (or was it a 44?) large chainring on the bike I often spun out with the narrow tires because it was so much easier to pedal than with the wide tires. I put on a crankset with a 48 teeth large chainring to correct that spinning out problem.
Cheers
Part of the spinning out problem is likely because you actually made your wheel a smaller diameter. And part is likely because most 2.125 tires are not the lightweight supple-casing tires that most narrower slicks are. If you get the same make and model tire in a wider size it will generally roll easier. If I am wrong and you changed from brand A, Model X tires in 26 x 2.125 to brand A Model X tires in 26x1.25 then I am mistaken, but I am willing to be that the different sets of tires had nothing in common besides the rim they fit on.