I am sure 25mm will fit, 28 maybe. But I think the 23mm tires that come stock are bigger than typical. If i compare the Kilo wheels side by side to my road bike with Conti grandprix 2000 tires in 25mm width, the Kenda's on the Kilo look taller. If that is true, 28's will fit for sure. I very much doubt 32 will though.