[gumby79]

How about a Cyistalite
G-30
Specks :

The G motor design for light weight and the rear wheel cassette free hub
It is with special outlet to make it different with other.
　
Motor power : 250 to 350 watt
Motor speed : 25km/hr , 30km/hr and 40km/hr
Motor weight : 3.8kg rear wheel and front wheel
　
Axle dropout :
Front motor dropout :
- 75mm dropout for 16" and 20" folding bike.
- 100mm dropout for front wheel /24" to 28" wheel bike
Rear motor dropout :
- 135mm for 8 speed or 9 speed cassette
　
Spokes for motor : G13
Number of spokes holes : 36pcs
　
Disc brake :　
Front wheel and rear wheel available for install disc brake,
Normal 6" and 8 " disc brake available.

I've run a crystalite 503 3kw @72vdc on
The hub drive motor was re spoked with DOT motorcycle rim. This was way to fast for your app. 45-50mph sustained @1500w load it yealded 157wh/mi and 50mi+ range on a 20ah 72v bat
The reason for a geared hub is ,no drag from the windings while pedaling.
My regen/ebraking was a fixed value,on or off, ming was set to 800w with a push button, and would cut out @~5 mph
the G-30 is specked at 15mph with a 26"bike tires @24v and accepts standerd bike disk brakes.
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Sensored or sensorless?
Sensored no cogging more failure points.
Sensorless cogging,simpler construction , cheeper controllers.
motor will start moving to figure out which way it is moving, switch back and forth between forward and reverse to figure out which way it's supposed to be going. Normaly 1/2" or less. Cogging is normaly on take off only and gone by .25-.5mph.