OK here goes. I have a hybrid with 700x35c tires and I would like to switch to tires with a more aggressive tread for winter commuting. (I have searched the forums, and visited Sheldon Brown's tire sizing website, but that just confused me even more ) So is the 700 the inner diameter or outer diameter of the tire? From what I've gathered it seems that it could be either one. The 35, I'm assuming would be the width of the tread. I converted the 700mm to 27.5 inches using my calculator, and If that is the equivelant to a 27" rim where did the other .5 go? I saw one website where a guy said he put 26" tires on a 700c, but for the life of me can't figure out how he made it fit. Anyhoo, I'm sure other people have had this problem so if anyone can recommend a wider tire size with a more agressive tread I would appreciate it. Maybe I'm over complicating things, but I like my hair and would like to keep it, so quick responses would prevent me from ripping it out!