Have not done a build as of yet on a bicycle. I have built a few other things from time to time, being a farmer boy you make a lot of things. Anyway I have been doing some searching and some reading. Is there a American made Kit w/Engine on the market? Follow that by other than China made, yeah I know the debate but if it is out there I will pay a little extra to not go China. Last resort I will go China though. I have a China compact tractor 20hp, cause well that is pretty much the choice on new or affordable compact tractors. Although the next size up mid size tractor went with a Mahindra India made tractor 35hp and it kicks ass over the quality of most anything I have bought in the last 20 years. As for as the bicycles has anybody made a small diesel engine kit, the torque of a diesel low RPM diesel drive might be a hill pulling son of a gun?