Oh, uh, the steel rims are 26 x 1 3/8 and currently hold 35mm Michelin Touring tires. I'd like to stay with that size to avoid brake/frame problems. I'm very happy with the safe feeling the wheel/tire combo gives me on bad or gravel roads. I'm not-so-happy with the brakes in the rain or after rolling through a patch of dew covered grass, though I can live with it, while keeping the diminished braking in mind. Will I experience better performance and faster speeds with the alloys and the same effort? There is only one type of alloy rim made by Sun that I've found in that size.