If you can take your hub motor apart it means the interfaces between bearings and their shafts and housing are slide fitted. I’ve found even with all steel parts, both 1020 and even 1144 steel, the shaft and housing will deteriorate due to the shock loading of a skate wheel. In the past I’ve use the best high heat retaining fluid available, loctite 620, this stuff is bearing glue and stops “creep” within the housing and on the shaft, which slowly eats away at them as the bearing bangs around, it’s an epoxy, but it can’t handle the loads and heat and deteriorates and you’re back to loose metal on loose metal and the creep continues. Simply put loose keeps getting looser and any machinist can look at these slide fitted motors and tell you it won’t last
If, worse, the motor uses an aluminum bearing housing or shaft, the deformation values of even 7000 series aluminum are way under even the softest steel, and they also have huge thermal expansion. if anything rattles it’ll keep rattling and get worse till the motor is done.
After selling 140 motors and them being out there for a long time I can tell you this from my own experience and feedback. I wouldn’t sell a hub motor anywhere there’s a mandatory guarantee on products because if someone actually rides a decent amount of time on a slide fitted motor it’s likely to be a paperweight before the year is over.
This goes for what I sold, Jacobs, raptor2, Carvon, and everything I’ve ever seen.
Even hardened steel skate axles deteriorate and they aren’t subject to the loading of a hub motor.
Loose always gets looser was obvious but also galvanic corrosion between the shaft and bearings was an interesting surprise. Just like a battery the slightly disimmilar metals touching produces an electrical reaction which also eats away at the metal. When ur playing with an airgap between rotor and stator that’s .4mm things must be precision and slide fittings ain’t it