Yes I think the mini motors because of the smaller diameter have gears.
The wife she lugs full trailers with a basket and baby seat packed full, she almost burnt the HBS36R Rear Hub Motor out once at 48v out, and I would be afraid to put the controller inside a hub with her driving.
Not all low volt motors are slow either it depends on the way the coils are designed to create magnetic fiels. Both current and voltage create magnetic fields. Voltage add throw distance and current adds torque strength. Increase torque strength and you can either use gearing to milk the speed and or a wider diameter rim. Again this concept creates heat too.
The HBS models and some of the others are from my knowledge all gearless.
What I mean by the electronics being capable of giving good speed is that even if you were to give the MP 72v with a 72v capable controller the BLDC controller design at this voltage is capable of delivering hall signals and synchronization with the hub with no latencies or excess heat due to higher RPM. By electric motor standards the Golden motor hub is a slug just asking for some energy and power and has much more potential inside it than we mortals experience.
The wider diameter MP coil speed across past the magnet is faster than the smaller hubs at the same RPM making the timing more difficult for the controller to keep up and add more poles into the simulation and you can guess what I mean. But when I say more difficult there is much more of this to be had, The electronics can most definitely do this so much faster than is required..
If the electronics are badly designed the motor may fail to deliver the signals correctly and the motor will perform sadly.
Yes more voltage is needed to make the MP go faster but my point being is that the wider diameter gives much more torque due to the leverage applied further from the centre of the hub and this has no effect to the top speed because this is dependant on the controllers ability to deliver hall signals fast enough. The angle of magnetic field from the coil to the permanent magnet is not effected so the whip throw effect remains almost constant.
High speed and high torque in a single package. Sure with some planetary gearing the MP would perform better, but those performance increases begin to suffer as the motor diameter increases. Similarly the wider diameter motor the less you need gears to supplement the torqe speed ratio.
If one could advance the hall sensors physically in the motor by 2, 3, or 5 mm depending on the size of the motor, add a delay to the signal, and variate it, this could be like an advance system to give greater speed increases when the load torque is low and RPM is high. The faster the coil moves across the magnet there is latency over the air gap between permanent magnet and coil. The concept is to close this latency up at high RMP to regain the benefits of the whip effect when the vehicle momentum is high.
