4-Speed Transmission

Since last october I'm working on my 4-speed transmission, and I carry it in my mind for 12 years. With an increasing amount of engine power, bike performance and worn out gears, my own original 4-speed jumping out of 3rd, time has come for a new construction. Different to Byford's Overdrive, this transmission is built with 4th gear working as direct gear, which means that in 4th gear the countershaft is running idle.

The new 4-Speed provides constant mesh gearing, needle roller bearings in the clluster gear and has harmonic gear ratios: On my 80cui Olliecammed sidecar with 24T sprocket, 1st is more reduced to give an easy start with large sprockets, 2nd fine for busy intown traffic, 3rd great performer from easy 20mph up to 70mph - especially good in mountains when direct gear doesn't pull enough and 2nd too high - the 4th works at all speeds higher than 30mph.