I weigh at 250 and have been running a pair of Specilized Rockhopper MTBs since November. One 19 inch frame belongs to the government and is my work bike. The 21 inch frame is my personal ride and commuter bike. I have been very lucky as I ride them hard, jump a lot of curbs and have yet to suffer any problems except for thorns popping tubes. Tuffy liners have stopped that problem.
My bikes are stock otherwise with the original tires and wheels. I hope they continue to provide excellent service.
I do not know the veracity of this advice but was told at the LBS that my MTBs were the best option for my weight and method of commuting. The tougher frames and tires will hold up better for me. So far they have been right on the money.
