Comment by pmyteh

I fitted a Bafeng mid-drive motor to my city bike and it's fabulous for hills. Because the power goes through the existing drivechain you can get high torque simply by switching to first gear. No minimum speed, power kicks in after half a turn of the pedals. Coupled with hub gears you can change at rest it's a marvel.

Even at the European street legal limit of 250W it makes acceleration trivial.