A lot of cross tires aren't available for 26 inch wheels. Kende small block eight tires are but at 26 x 2.1 they're a big large for the XO series. I have a few 26 inch bikes (2 vintage stump jumpers that I use for mixed surface ring and commuting and the b'stone XO-2); the pickins are a bit slim when it comes to 26 non MTB type tires.