I already posted on another thread, but I decided to copy it here and add a little to it.
I found this site by accident when I was looking for info on bike frames for engines. I bought an old bike from a flea market and then I bought one of the miniature motorcycles with a 4 stroke 50cc with a 4 speed tranny and a centrifugal clutch which I decided to put the motor on the bicycle. I don't know about this bike build off, or if I could get it done by the deadline. I have to first get my welder fixed before I can modify the frame to accept the motor.
The miniature motorcycle is fun, but I can't legally drive it on the road. It is supposed to be able to go about 50mph as it is, (I haven't tried to see) With the tires being much taller on the bicycle I think it would go to fast to be safe if one wanted to go there. lol Anyway, glad to have found others that like the same hobby I do.
If anyone has already tried to do a build similar to this I would be happy to hear, and hopefully learn from their experience.