CHAIN & SPROCKETS changed to BELT & PULLEYS. Doable?

Discussion in 'Transmission / Drivetrain' started by Max-M, Mar 28, 2013.

  1. Max-M

    Max-M Member

    10-tooth on clutch, 56-tooth on hub: can I convert to pulleys and a belt?

    Some things I've read on this forum recently have rekindled my interest in the possibility of running an all-belt drive.

    I've got a 49cc, 4-stroke Hua Sheng 142F, mated to a Q-Matic drive. It seems like it would be a pretty simple matter of replacing the sprocket-type clutch on the Q-Matic with a clutch that has a pulley attached. And then replacing the 56-tooth final sprocket on the rear hub with a pulley of the similar 9+ inches size.

    I can just find an appropriate size of belt, and then get the installed belt adequately tight with my spring-loaded tensionser.

    This all seems so obviously do-able; am I missing anything here in my thinking, and are the necessary parts readily available from McMaster-Carr, et al?

    Also, I wonder why the pictures of Whizzers that I see always have a rear pulley/sheave that's nearly as large in diameter as the rear wheel of the bike.

    Thanks in advance for any thoughts.

  2. Max-M

    Max-M Member

  3. dchevygod

    dchevygod Member

    You are running a gear box that reduces the rpms so a smaller rear sprocket can be ran. And yes as long as you maintain the same final drive ratio your belt drive conversion will work like a charm! Take a look at a toothed belt setup for less chance of slip. Golden eagle bike engines aka GEBE runns toothed belts and the cogs are available as timing belt parts " 5m pitch timing belts and cogs " I ran a 14:2?? I can't remember because a gebe sheave isn't toothed all the way around but it wasn't reduced.

    You may need to go a bit bigger in size of sprockets to keep the same ratio. I mean I think that the pinion gear " motor gear " might need to be 12-13t and to keep the same ratio the wheel sprocket would need to increase.
  4. Max-M

    Max-M Member

    Thanks for your thorough reply, dchevygod! I think I'll try this conversion this summer.

    Cheers, Max
  5. Racie35

    Racie35 Member

    The whizzer sheaves are usually the same....around 15" they don't get to choose.... You can change the size off your clutch or jackshaft if used to attain your proper ratio