Which freewheel to buy for SmartPie

[TheModfather360]

Hi there, I'm buying a SmartPie, how do I know which size freewheel to buy? Like what is the width of the freewheels? THanks

[Bikemad]

The Smart Pie will typically accept up to a seven speed thread on freewheel without any problems, but some freewheels may require an additional spacer washer on the axle to prevent the chain from rubbing against the frame, although this seven speed unit did not:



It will also accept an eight speed freewheel unit with an additional spacer washer on the axle to provide additional clearance.

If it's for a road bike, I would suggest going for a freewheel with an eleven tooth sprocket to provide higher gearing so your legs can keep up with the motor more easily.


Seven speed 11-32T DNP Freewheel.


Eight speed 11-32T DNP Freewheel.

If your bike has more than eight sprockets on the current freewheel it might work with an eight speed freewheel by adjusting the end stops to prevent the chain from coming off, but without the correct changer mechanism you may find that it won't run 100% smoothly in all of the gears.

Alan
 

[TheModfather360]

Ok thanks. I'm just worried about buying it and it doesn't fit.. but if my current bike has 8 speeds, I should be good with 8 speed freewheel and the smartpie? Or should I get the 7-speed just in case it doesn't fit?

It's a mountain bike, I'd probably like an 11-tooth anyway though. It's a steel bike so I don't mind widening the dropouts a bit in the worst case.

[Bikemad]

I would go for the eight speed freewheel and retain the same number of gears and spread the frame slightly if necessary.

If you look at my review of the Smart Pie you will see how I widened the dropouts in my steel frame by 10mm, but you should only need 2~3mm extra on yours at the most.

Alan
 

[TheModfather360]

I checked the bike again and it seems like 7 gears on the back wheel, so i'll go with the 7 speed.

I didn't buy torque arms and instead opted to build them myself, my friend is a machinist.

I plan to use this bike for a few months and resell it and then upgrade all the components, hopefully I won't have problems with the SmartPie internal controller during that time..