Re: Hello all.
I made a gearbox so I could get some hill climbing help. If you search perrincycle you'll find a little vid [ poor quality I'm afraid]. It uses a 31cc Honda powerhead and a seven speed Shimano hub. It can get up steep hills in the lower ratios and does 45 kph on the flat. The pedals are synched to engine revs in each ratio i.e. 60 pedal rpm= 6000 motor rpm in each gear.