I am using QS3000 mid drive motor with these specs.
Magnet Height: 70mm, 40pcs, 5 pole pairs
Diameter of stator: 138mm
Rated Power: 3000W (peak power, pending)
Rated Voltage: 72V as default
Speed: 90KPH
No-load rpm: 4400rpm without flux weakening, 6500RPM with flux weakening. Max Torque: approx...