Re: Need advice. Second build
I would put the motor on the bike that I deem the most sturdy. I know nothing of the Panama Jack bike, but my inclination would be the Trek would be the stronger bike. Even though it has lots of gears I find that I really dont change gears too much on my bike, since I use the motor for the most part and only really need one easy pedal gear to get rolling. So if the Trek has dérailleur problems from sitting outside it might not be a big deal, as long as you can get it set in one gear that is easy to pedal. BRAKES are what you should really be looking at, use the bike with better brakes and stronger rims, you're gonna need 'em....