Quote Originally Posted by roo4 View Post
Did you notice a difference in speed when you first got them?
They came with my bike. So I cannot really tell.

But my husband saw a huge difference with the Shimano he had originally on his Cervelo R3 (which he traded in for Cervelo S3 this past May). Mavic Cosmos that came with his Cervelo S3 were ok but he much prefers the AM Classic Aero. And he's tried the 23mm and 25mm tires on them. He likes his 23mm because of look (comes in red) but prefers the 25mm because tougher on flat tires with our bad road conditions.