Quote Originally Posted by TigerMom View Post
I can understand the more comfort part, but I don't understand how a 700x25 cc can make you faster than a 700x23 cc since there is more friction contact with the road .
Well my eyes glaze over when I try to read about tires, but there are a number of articles out there about it. Here are two:

http://velonews.competitor.com/2012/...rethren_209268

http://velonews.competitor.com/2012/...-faster_209888