gear ratios/ hf

  1. C

    Gear ratios for HF bike -- please help!

    I'm bulking a motorized bike with a 3hp, 79 cc Harbor Freight engine that's on sale for 79.99. Max rpm is 3600 without making internal mods. I'm using a 12 tooth clutch off the engine to a jackshaft in. The jackshaft out is the standard bike gears (the large three sprockets in the front) running...