chain drive on centrifugal clutch


Local time
4:10 AM
May 21, 2008
clearfield utah
can anyone tell if this would be more trouble than it's worth. it's just an idea at this point. i put the pictures in the picture gallery. i'm thinking that welding a sprocket to the opposite side from the freewheel. then a smaller sprocket to the freewheel of the centrifugal clutch. take a look please and tell me if the 60's were simply too much fun. the engine would be mounted over the rear wheel. you can reply here or send to :???:


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It would work. You would have gears too! But you would need that thinner derailier chain but that may be okay in itself.
Fabricate a derailier sprocket in the centrifugal clutch then line up the sprocket to the middle drive sprocket. Then get a derailer so you have the tension and bring the cable to the handlebars for gear changing! Setting the sprocket in the middle would mean that the high and low gears when engaged would still line up right.
That wheel sprocket would have to be welded and fixed. I don't see any room where you can bolt it on like you do with Happy Time sprockets. Then you'll need some kind of adapter to mount the sprocket to. Unless you can weld it right on the axle. Would there be enough room for the chain against the spokes?

I see 5 holes on the big gear. If you can mount that to your spokes like in the Happy Time Sprockets and shim up some washers on the axle and double nut it centering the whole mess it may be strong enough.
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i was planning to weld the 3 sprocket in the picture right to the axle. of course i would have to ream it out some so it fit square on the axle then weld it. both pieces are steel. already checked to see if i coulod get the whole assembly back in the original rear forks. so far don't see a problem. it's all a work in progress, with the details in my head, possibly lost forever. :???: the derailer sprocket is a good idea as long as it's made from steel also.
I don't know if you're going to have enough gear reduction without some kind of gearbox on the engine. Search the forum for gearing calculations but I'm pretty sure you're going to over-gear your engine without more reduction.
i just re-read this sounds like i wrote it. i didn't. in the quotes is from jpilot "I wrote a little gear ratio calculator that some might find handy. The program can be downloaded from"
back to the drawing board !! a 14 tooth sprocket on the motor and a 48 tooth on the hub would give me a max speed of 248 miles per hour. that's probably illegal :???:
Impractical too,you would have run out of torque a long. long time ago.That is the problem with all these schemes,typically you need something in the order of a 20 or higher reduction between engine & rear wheel (26"), which means a two stage arrangement.In the Dax-75 there is an internal 5:1 engine reduction so only one chain drive is needed,which is nice.