Grinding noise from Torq motor

[rsscott]

Something that happened very early on with my Torq was a loud grinding sound coming from the motor. This usually only occured when pulling away but sometimes happened a little bit further into a ride. Having said all that, I've covered about 1,500 miles on the bike and I can't recall it happening for some time now. Anyone else experienced this?

 

[flecc]

Grinding Noise

Yes, when my bike was new, but it had to have a new motor as it was a really bad case, locking up the wheel. The problem for this type of hall motor is that the rotor drum revolves aroung the fixed armature, the drum having a pinion on the end which drives the orbital gears. Thus the drum which carries the motor magnets is largely floating around a single side bearing point. If it skews due to a sudden high loading, the drum magnets can hit the iron pole ends of the armature or the hub alloy casing and grind against whichever it is momentarily. The Torq is the most likely to suffer this due to the high gearing and resulting torque stresses.

 

[flecc]

Motor Noise

I'd previously done a write up on the noise these motors make, so I've now published it as a page on my website. It's not linked into the site yet, but here's a direct link to that page:

http://users.tinyworld.co.uk/flecc/motor_noise.html

 

[flecc]

A bit of additional information on this when it occurs right out of the blue and disappears later. Drops of dirty (i.e. conductive) water getting inside the controller can end up on the thermostat part of the circuit inside and cause intermittent firing of the hall circuits. This unbalances the armature and causes it to rub against the armature poles and/or hub casing, with a characteristic destructive grinding noise. There's more to this, and I'm going to put something about it on my Torq Talk site. The prime route for this water ingress is probably the cable from the switch carrying it into the controller case.