I've got an early Colnago Super that I've run Avocet 700x25's (22 mm?) front, 28's rear for ages. Maybe originally because of tire supply, but it works well. I have a 26 tooth freewheel on the back for the hilly terrain in my area, and pull the hub back fairly far dropping the rear of the frame a mm or so in order to get the Campy to do it well. I figure the larger tire restores the correct fork angle and I like having a bit extra rubber on the back. Is that a bit anal? I do generally ride 25 to 28's regularly on the road with a 32 thrown in a bit and pretty much the same size front to rear.
Dan Artley in Parkton, MD
Has anyone ever actually run different sized tires front/rear on their vintage bikes? I don't think I've ever seen it. I've always thought that having different reach brakes f/r was illogical.