Seven (ste)Elium, Trek Top Fuel 8, Gitane TdF, Trek Fuel EX 9.5
What's the minimum width for a tire in order to be effective in racing? I have a frame that doesn't have a whole lot of rear clearance, and I'd like to get into cross racing (in SE Virginia, if that affects anything-- not a whole lot of mud, more grass and packed dirt it seems). How wide do I need, and do people have favorite tires on the narrow side of things?
32s are pretty nice. The wider the tire, the more cush it is across the bumpy stuff. Smoothing out the bumps translates into faster. So if you're > 185 pounds, go with 34. Otherwise, go with 32. However, tire width won't mean much if you don't ride with the pressure as low as you can go.
I rode Vittoria Cross XN 32C clinchers last year on a Surly Steamroller with caliper brakes. They seemed to roll really nice over grass and dirt, nice traction on dry stuff, and I never pinch-flatted even with pressures at the low end of the range, so this year I'm getting a pair of the XG tread in 34C.
The tread wears very quickly, though, so save them for racing.
I have found Bontrager Jones CX tires to be a good all rounder clincher. Not sure if they go to 28 but they do have a 30. BTW often times these measurements look vastly different between the brands of tires. If you are thinking of getting new wheels too then tubular is the way to go in cyclocross racing. Tufo is a fine brand and My current favourittes are Griffo 34's.