syimotor
https://www.syimotor.com/ebike-mid-motor/
Mid motor is mounted on the frame where the pedal crank is. Mid motor are far more complex than hub motors, which also cost too much. The major advantage of the mid-motor drive is the mechanical characteristics offered by the gears. Mid-motor bikes could clearly outperform hub motor bikes having the same motor size on hills. If hill climbing ability is important for you, of course consider a mid-motor which has the additional cost, and reliability in mind. Mid-motor also tend to be a bit heavier than hub motor. There are other advantages, torque, you could climb a mountain, balanced center of gravity, safety.