Well, I believe all my problems have come to a pinnicle. If you read my other threads, you'll see that I am having issues and can't seem to find the culprit. 1] Can't accelerate past 1/2 throttle. 2] Very rough engine at 1/2 throttle. 3] Sheared a mounting bolt. And now this, I sheared another (the other rear) mounting bolt!!! OMG! I want to scream! Well, luckily when I bought a replacement for the first, I bought 3 extras as well. So in the process of replacing this one, I noticed my rear freewheel hud was off the axel. The nut that keeps it in place had come loose. It looked as if I had also lost some bearing in the rear axel area. So after I tapped and removed the sheared mounting bolt, I took the whole rear wheel assembly to my local bicycle shop. Surely, they would be able to properly reassemble the rear hub. I took it in and the guy said that I had completely shattered my rear freewheel assembly. I figured as much. I told him to replace the freewheel hub and overhaul the bearing/axel. Now, I wonder. If my rear axel/hub was so bad, could this have caused the mounting bolts to shear? And if the motor is properly mounted/stabilized, could the excess vibration cause the motor to have a low RPM limit?