CHAIN & SPROCKETS changed to BELT & PULLEYS. Doable?

[Max-M]

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.

 

[Max-M]

 

[dchevygod]

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.

 

[Max-M]

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

Cheers, Max

 

[Racie35]

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