I am a habitual tinkerer, this thing needs gears. The old Suzuki trail had an outfit that would allow you to change from trail gear to road with a flick of the switch. What if we were to install the two sprockets each with its own chain and then at the device that the engine chain goes to we would install a cable to a changer, and val la two speed. I think it was around 1966 for the bike, Ill look for the thing. Have fun, Dave