I ride older Cronos wheels. 30mm. OK as training wheels, but next spring I'm going to be upgrading them. I'm not sure if it's the wheels or the fork or frame, but when I climb out of the saddle, and rock it hard, brake pads rub the rim, so they may be flexy that way. And they weigh in at around 1900 grams. But they do seem to be rock solid and bombproof. So I'll keep them around for training purposes.