When I got my Trek 720 tuned after years of disuse; it came back from the LBS with 700x45c on it. I am not happy with that as I do not run off road and the only real bumps are the what the normal wear and tear on any Kansas road is after a long winter and the state having little or no money to do road repair and what has been do is not the shoulder where I ride. Having said that I expect 700x35c's tomorrow. I also will be getting even thinner tires before doing any long event rides next spring and sumer like 28-32's.

SO I guess my answer is I know that on an old trek 45c's fit so . . ?