E-bike motors can be bought from many places. Amazon, E-bay, Aliexpress are all fine places to find your motor on a budget. Higher end websites like www.ebikes.ca (Grin) are also great places to find higher end motors.
Brushless motors for e-bikes are a very mature technology and you can shop just about anywhere and expect to get a very usable motor. Wattage and amperage ratings however can be very strange to say the least and many advertisements bare little resemblance to reality. Many sellers will sell 250W/500W/750W rated motors that greatly exceed those specs, underrated so they can advertise to people looking for a legal motor in their country.
Others will over rate their motors to make it more attractive to people who wish to get maximum performance.
A better indicator is to ignore watts and look at amps, they tend to lie less about the amperage rating. Multiply your battery voltage by amps to get your true wattage rating. For example a 10A controller on a 52V battery will give you 520W.
Below is a list of the most common Mid drive motors:
- BSS02 (25A at 52V, 1300W)
- BSSHD (30A at 52V, 1560W)
- BSSUltra (30A at 52V, 1560W, built in torque sensor, requires custom frame to mount)
- Cyclone (40A at 48v to 72v, 2KW to 3KW)
- Cyclone Mini (40A at 48v to 72v, 2KW to 3KW)
- TSDZ2 (14A at 52v, 750W, built in torque sensor)