You can get a variety of diameters using different tire makes, all good but there are still advantages with 650's even if on average they do not equal the avg. 29r height. A simple solution for those that discount the 650: try it. It's not too close to a 26r or not enough of a 29r as some arguments go but really, how many people have actually tried it before writing it off? It could go from whining to hooting after one ride.