Sitting out drinking wine and looking at my "old" road bike today. It's a circa 1999 Specialized Allez Sport. I never have ridden it much as its just not comfortable, but I noticed today that the rear tire is a 700x25c, and the front is a 700x23c. Anybody else riding on 2 different size tires? I have been doing that for about 3000 miles on that bike. As the sole owner, it came that way too!