quick answer: I need a new rear rim. long answer: The rear wheel has been holding up fine, but i think due to its low weight, they sacrifice some of the strength. the thing is, the bike is ridden in a generally rocky area (SLO), so the rim took a lot more than i think normally the places people would ride. riding in Oregon and Santa Cruz, the wheel seems to be holding up fine, but I'll be rebuilding the wheel very soon. probably replacing it with a WTB Frequency i23. not cracked, or broken, just out of true, and dented.