I built two bikes with the BPM motor in the front wheel. They are OK up to 25amps and 44v (about 1.25kw from the battery), but you must have torque arms to stop the axle breaking the forks. I made my own. torque arms.
Rear wheel installation can also give problems. This motor makes a lot of torque and can be dangerous at low speed with 40 amps. It's OK on a good road surface, but on grass and mud it's difficult to stop it spinning and you can high-side if not careful. At 25 to 30 amps it's better. If you fit a rear motor, you also need good torque arms.
Rear wheel installation can also give problems. This motor makes a lot of torque and can be dangerous at low speed with 40 amps. It's OK on a good road surface, but on grass and mud it's difficult to stop it spinning and you can high-side if not careful. At 25 to 30 amps it's better. If you fit a rear motor, you also need good torque arms.