I would like to build my first bike using a mongoose mtn bike frame. I was wondering if anyone could tell me how to fit the engine over the rear wheel rather than in the middle of the frame.
You'll need a rear mount setup. There is a few different options when it comes to that. Thatsdax.com is where I would go for a rear mounted setup, but I'm more of an in frame guy myself. Duane at thatsdax can answer all your questions, give him a call.