JennyB
1 kW
SM = Stoke Monkey. Hubmotor drives chainset drives wheel
Mid = Chainset drives hubmotor drives wheel.
In both cases the hubmotor is supported by its axle and its body spins.
Either allows the motor to work through gears so that it operates at maximum efficiency over a wide range of speeds. This is most desirable for velomobiles and cargo bikes. Since it is driving through bicycle parts, the motor should not be too powerful, nor need it be. The Stokemonkey motor is EU-legal (so long as it is not used to assist above 15). It uses a direct drive rear hubmotor driving a left hand side chainwheel. The motor is mounted with the freewheel on the left hand side, and so it needs to be modified electrically to spin anticlockwise, the opposite direction to normal. The freewheel, spun onto the hub in the normal manner, ensures that the motor does not rotate with the cranks when power is off.
At first sight it would seem possible for an unmodified motor to power the right hand side, simply by flipping the freewheel before screwing it on - but in that case power applied would tend to unscrew the freewheel on its clockwise thread. A suitable hub motor therefore needs to be about 250 watts continuous rating and either run anticlockwise or allow a sprocket or freewheel to be attached without unscrewing.
Which motors are most suitable?
Mid = Chainset drives hubmotor drives wheel.
In both cases the hubmotor is supported by its axle and its body spins.
Either allows the motor to work through gears so that it operates at maximum efficiency over a wide range of speeds. This is most desirable for velomobiles and cargo bikes. Since it is driving through bicycle parts, the motor should not be too powerful, nor need it be. The Stokemonkey motor is EU-legal (so long as it is not used to assist above 15). It uses a direct drive rear hubmotor driving a left hand side chainwheel. The motor is mounted with the freewheel on the left hand side, and so it needs to be modified electrically to spin anticlockwise, the opposite direction to normal. The freewheel, spun onto the hub in the normal manner, ensures that the motor does not rotate with the cranks when power is off.
At first sight it would seem possible for an unmodified motor to power the right hand side, simply by flipping the freewheel before screwing it on - but in that case power applied would tend to unscrew the freewheel on its clockwise thread. A suitable hub motor therefore needs to be about 250 watts continuous rating and either run anticlockwise or allow a sprocket or freewheel to be attached without unscrewing.
Which motors are most suitable?