rear geared hub motor locking up in subzero temperatures

[Klauts]

hey everyone, I'm experiencing the above issue with my bafang G60 750w rear hub motor. it's about a year old, this morning when I went to bike to work the motor made a wierd clicking sound when I activated the throttle. I powered down and removed the battery and discovered the hub motor wouldn't rotate backwards only forwards, so in a desperate attempt to fix it hoping it was just cold I put it in my house and walked to work.

when I got home the motor was working like normal.

I'm assuming I've either got water intrusion and ice formation or possibly the lubricant in the motor isn't rated for the cold... it was -7⁰c when this occured.

if it's moisture and I open it up to find a bunch of rust, what is the best way to salvage the motor?


if there's no moisture is it safe to assume it's the grease/lubricant causing issues?

 

[neptronix]

-7c is -19f and various kinds of lubricants turn into solids at that point, for example on my mazda2, if we get to 15f/-9c, my car's windshield wipers just groan when i engage them.

Was the bike left outside?

 

[Klauts]

-7c is -19f and various kinds of lubricants turn into solids at that point, for example on my mazda2, if we get to 15f/-9c, my car's windshield wipers just groan when i engage them.

Was the bike left outside?

yes the bike was left outside overnight, the battery was inside and warm.

I had a bafang g62 that I used for two years in Calgary with up to -40⁰c temps and never ran into issues so I didn't even think about it being a problem with this new motor

 

[neptronix]

Interesting, were they indoor or outdoor? that would make the difference.
If you can have the bike's motor at at least above freezing, riding in very cold weather should be okay because the motor heat will touch the lubricant first before the cold air passing through the motor shell hits it, so it should remain in a non-solid state as long as you give it some help.

Funny to have some of the same problems as an automobile!

I would worry about ice intrusion. No hub motor is truly sealed so ice can form when we get a combination of humidity and below freezing weather. If you do an inspection, post the pictures.

Direct drives work great in these conditions BTW but can also suffer of water ingress if left out in freezing cold.

 

[Klauts]

I had it outdoors year-round in Calgary as well, that's what initially had me thinking water intrusion over hardened grease. I bought the g62 from a more reputable Canadian company and the g60 was just an AliExpress deal so that could be the difference