Magnet width and stator width on hub motors Like HBS anyone have info ?

[Thaialien]

Hi guys I have many hub motors Width of Magnets like Width of wheel !
Some are 24mm some are 27mm some are 28mm and some are 31mm OK  350w to 1000w think !
stators charnge too are nearly the same ! OK
you can use slimmer stator with larger magnet OK but not the other way round.(power loss )
Trying to get more info  !
Also anyone know how they work out windings ?
if you get a 16inch or a 18 inch same wattage from same Mfg. they seem to run at differnt RPM freewheel but run to 34kph each of them ?

[MonkeyMagic]

if you get a 16inch or a 18 inch same wattage from same Mfg. they seem to run at differnt RPM freewheel but run to 34kph each of them ?

Because of the wheel/tyre diameter. Winding for rpm but less torque or vice versa, but smaller wheels having more toque anyway there would be little difference in performance