I have the rockhopper and the problem was on the rear wheel. I bought a second wheelset which I use for off-roading...it's a factory built set, but I had a mechanic check the spoke tension and whatnot and so far so good. I was amazed with the problems I was having though, even the crappy dept. store bike that I had sitting in the garage for 10 years before I actually used it went 430 miles with no broken spokes!