Hello I am very new to the forums. I have little experience with working on bikes or small engines. I would like to build a bike with one of the HF engines a 99cc or 212cc and have done some research. I found this build, http://motorbicycling.com/showthread.php?t=36131
but I don't understand why so much is required please explain why a things like a clutch and jackshaft are needed and why I couldn't just run the motor to a front freewheel. I apologize for my lack of knowledge like they say someone who asks a question is a fool for 5 minutes but some one who doesn't is a fool forever.