you can run 25s on rims with up to 17mm interior width, though I bet you could go up to 19 with quality tires. Have a half cyclinder profile is now preferred to the lightbulb profile of yesteryear. It corners better and is more aerodynamic.
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1 Super Record bike, 1 Nuovo Record bike, 1 Pista, 1 Road, 1 Cyclocross/Allrounder, 1 MTB, 1 Touring, 1 Fixed gear