DougG

I also agree with the tire pressure comments. However, in case you do consider wider tires, you will find that the limit on width is usually determined by the design of your bike, or more specifically the width at the front of the chainstays where you obviously need clearance. The "racier" bike models are usually too tight to go much above 700x25.

My Specialized Sequoia came with 700x25 tires and I managed to put a set of 700x32s on it, which greatly improved the ride smoothness at 80-85psi, only to find that the brake shoes wouldn't open wide enough to remove a wheel unless I deflated the tire! Fortunately I found some Tektro long-reach calipers that solved this problem.