Wow! I accidentally stumbled onto this site and it's just what I was looking for. I won't be able to contribute much because I've never built a motorized bike before. (Whoops! That's not quite true. I did put a 1 1/2 hp Briggs and Stratton lawn mower engine on my Firestone bike back in 1958. Does that count?) I'm here to ask questions and learn. I'm on the verge of ordering a 50cc motor from eBay to put on a bike. I'm kind of handy, but no mechanic. I think I can learn pretty fast. Looking forward to learning from the "pros" on this site.