Another fork motor question

Desertprep

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If the fork had a 3 speed hub gear with a chain drive motor would torque be reduced, i.e. would stress on the fork be reduced?
 
:shock:

Fork, meaning the front fork?

Just the oppisite. lowering the gear ratio lowers the speed, but raises the torque preportionatly. if your gears are 1:1 , 2:1, and 3:1 then the 1:1 would behave like no gear reduction, 2:1 would cut the speed in half, but DOUBLE the torque, and 3:1 would tripple it. on a front fork, this is pretty much an instant failure.

I don't think you could fit a 3 speed hub into a normal front fork. its too wide. it would need to be custom built to fit, and to take all the extra torque, plus have some way to mount the motor. And with the extra torque, it would need to be a big heavy unit. Another problem might be the headset bearings. they aren't designed to handle a sideways load like that, and with enough torque on them, they may fail.
 
is there a particular reason you want a front-drive bike motor that is not a hubmotor?

chain-driven electric motors that power the rear wheel mean you have more places to mount the motor.

Another downside to front-drive is that if you mount the motor to your headtube the chain will have to twist as it goes down to the motor whenever the front wheel is turned.
 
Is that even possible? Mounting to the head tube? I'd think not.

As long as the motor is fairly light weight, I don't see why bolting it up to the fork is a big deal. Have you ridden a bike with one of those gasoline friction drive setups over the front wheel. They seem to work ok so a little four pound dc motor should be fine with regards to weight. I don't see why you would gear it any differently than rear drive.

If you're asking if there would be less worries compared with a hub motor, you don't have that axle twisting out stuff to worry about.
 
vanilla ice said:
If you're asking if there would be less worries compared with a hub motor, you don't have that axle twisting out stuff to worry about.

Well, thats true, but if and when that chain slips off the sprocket, or snaps there's a good chance it could jam up the front wheel. I've had that happen a couple times on the rear wheel. Wheel lock on the back is a bad thing. wheel lock on the front is far worse
 
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