AHicks
Well-Known Member
- Region
- USA
- City
- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
A mid drive motor is not better engineered than a hub motor. There is really not much to engineer, it is a pretty mature and simple design.
The difference is:
-Hub motors rpm completely depends on your speed(since there is no gearing in between the wheel and the motor) at low speeds the rpm drops, the motor runs in the inefficient band and its power output falls significantly below its peak.
-With a mid drive rpm is completely dependent on cadence and when climbing if the gear ratio is right one can keep the cadence hence rpm in the motor's efficient range where it can also produce close to its peak output.
Yes it is simple physics and it is all about output power vs rpm graph not the peak numbers. Ebike companies don't give you that, instead advertise those meaningless peak numbers of Torque etc.
So here is the conclusion,
On very steep hills with the right gearing you can keep the cadence of a mid drive in the efficient band hence can expect mid drive to be more efficient than a hub motor.
Otherwise, hub motor will not suffer the losses at the drivetrain and be more efficient than the mid drive.
I struggle when people write about "hub" drives discounting completely the potential for gear driven hub drives. That omission skews most of their comments into uselessness.