I'm gonna have to disagree with the portion of the argument about the rider being overweight. A weak frame is a weak frame, regardless of weight. Perhaps a heavier rider will cause a weak frame to break more quickly, but the problem is still the weak frame. I weigh around 275 (here come the fat jokes, no I don't care if you don't like my weight and calling me fat won't answer the OP's question so move on already) and I have NEVER broken a frame, motorized or otherwise. My first two motorized bikes were built on department store bikes and the first one did crack, but I wasn't riding it and the motor mounts had come loose and the motor was vibrating violently in the frame. I believe that's what broke that frame. I had given it to a friend who did not maintain it as well as I did. My second frame still sits in my basement till I figure out what to do with it or get rid of it. The frame I'm riding now is a repop schwinn cruiser with quarter inch thick walled tubing. The bottom line is that a strong frame will carry a heavy rider without issue, and who cares if someone is overweight? It's perfectly logical to assume that an overweight person might get offended by the word fat, and it's an ugly, hateful word. No, I won't lose weight for you. I should not have to change for other people to accept me. I should not have to lose weight so people won't call me fat. It's my body and my choice. I'm not trying to pick a fight, but if you have the right to judge me, then why don't I have the right to defend myself? Fat is another word that hateful people invented, and using it to describe another person makes you hateful too. It's no different than being racist. Fat, h.o.m.o, the "N" word, white trash, hick, redneck, they are all the same.