Vairy interestink...

Ludwig II

Member
Local time
6:48 AM
Joined
Aug 16, 2012
Messages
329
Location
UK
I just found a potential source of 90 degree reduction drives. Tillers/cultivators. There's a Ryobi which is 6.52:1, a handy figure. Is this of any use to anybody?
 
They might work well. One thing to consider, though. They are typically worm drive gearboxes, which don't work in reverse (being driven by the output shaft, back through the gearbox to the engine.) If you have a direct hookup between the output shaft of the gearbox and the rear sprocket, and you let off the gas, your rear wheel will suddenly be turning at the reduced RPMs, (and once the clutch disengages, zero RPM) and not the RPM that your speed would LIKE your rear wheel to spin... Can you say "Road Rash" ???

To work around this, you would need to use a freewheel sprocket at the output shaft of the gearbox, to allow you to coast/brake down to lower speeds when you let off the throttle.

I would be interested in taking a look at these gearboxes though. A 16 tooth freewheel sprocket to a 48T rear sprocket and a 6.52:1 gearbox would be about right...
 
I hadn't considered the drive reversal and, now I can, I can see you might have a degree of resistance to it. Your freewheel idea sounds useful though.
 
Back
Top