Hub motors are the most in-efficient way of using electric motors. China has been notorious for using Hub motors in all its 2 wheelers in e-cycles & e-scooters. It is the most easiest and simplest to use, all one got to do is remove the front wheel and replace it with the Hub-motor-wheel and fix the controller plus battery and you are ready to go. It is available from Rs 10,000 to 20,000 for the entire kit add Rs 1,000 for shipping to your doorstep!
Hub motors are ok to be used in toys, school science projects and by amateurs. But selling it installed in scooters and… motorcycles as a “complete” EV product is nothing by taking them for a ride. Many fly-by night operators who use this to make a quick buck milking (according to them) EV-Fad.
The biggest looser are the EV market. Most of these manufacturers do not know why their vehicles give unsatisfactory performance and blame it on Lead Acid battery. They do not understand that the vehicle has been built inefficiently.
Turn a wheel at the rim and the force you apply (red arrow) is multiplied to give a bigger force at the axle (blue arrow). The bigger the wheel, the greater the effect, because the radius of the wheel works like a lever.
You can use a bigger wheel to multiply speed.
However, if you apply a force at the center of a wheel, the leverage works in reverse and you get less force at the rim… and this is what we get with a hub motor.
The reason hub-motors are inefficient are because they try to turn the wheel from the center. Its common knowledge that the most difficult way to turn a wheel is from its center and the most easiest way to turn a wheel is from its edge either with a bigger sprocket or by hub-less wheel.
Below: Electric Bike with large sprocket almost as big as the rim coupled to the motor at the center can create enormous torque unlike with the Hub motors.
Bigger the sprocket the better the power but big sprockets can brush the frame so that has to be built accordingly. Or you can use slightly smaller sprocket.
And there is no need for the traditional pedals to power the cycle but you could combine pedal to comfort any potential client.
Climbing flyovers even with a 250w motor will feel like a 750w motor!