Q100 compared to Tongxin?

[Geebee]

Several questions, this is for a lightish build ~17kg inc battery and motor plus me roughly 75 kg, 20" wheel, 36v ~15 amps
Torque difference?
Noise difference? (my head is 40cm from the rear axle)
unpowered drag difference?
Interchangable using the same length spokes?
Can the Q100 run sensorless, I always pedal first?

 

[Deleted member 4366]

The torque depends on current. The Tongxin slips at something above 12 amps. The Q100 is happy at 18 amps.
The Q100 isn't silent. You get a bit of motor wine, and the odd resonance noise, particularly when new. You'll hear it at 40cm. It'll probably be quieter with a sine-wave controller.
Unpowered drag is a difficult one. There's certainly not enough to worry about.The whole motor disengages with the clutch leaving only the hub to rotate.on its bearings.
The Q100 doesn't run well sensorless.It can be rough and noisy throughout its rpm range, and it can lose sync at high speed, which makes it judder.