The question is if they have been designed for 3kw
for something costs 30$? i'm not sure, look at all the options aft bring up from prolonging the life of the gearbox? and that's only for 1680 watts.
i currently own a gng 2015 and it's goes to around 52 kph at 48v nominal baattery at 1700 watts. pretty similar to this, it's usage is 25 wh/km (whats the usage on this i wonder). it works well now after i replaced the entire crank with my own spider.
it's casted jackshaft holder holds and doesn't bend. and that means that if could pull out the jackshaft from it you could replace it with something stronger, that would accept better freewheels and better 8mm chain rings.
the only thing i'm worried about in my gng is the motor's own driver sprocket, there doesn't seem a way to remove it (no key, no allen bolt) it doesn't seem to unscrew. the only way i can think about is it's pressfit into the shaft, or that pressfitted into part of the shaft that was later bolted though the brearings.
if could i could solve that mystery then i'm think i'm golden on all wearable parts.
even more, i may even be able to use a thun 136 mm bb on it, as it seems to have big clearance. unlike this thing.
actually i was these are the same motors
the advantage this motor has is that it can be fitted to any bb. maybe less noisy.
Trek 7.7 fx, 22.5" frame, 38x700c,10 gears.
ecospeed mid drive 1300 watt engine, max speed 45 kph.
battery1: 48v 14 ah, frame mounted battery, range 40km.
battery2(spare) 52v 10ah frame mounted bag, range, 30km.