QS205 metallic noise between 66-69kph freewheeling.

[TwisterGripper]

https://www.tiktok.com/video/7367380868098198789

(Onyx RCR with 41ah battery option)

riding ~1 summer no issues until now. While riding on a dirt trail, coasting down a hill rear wheel locked up or nearly locked up (not sure) - no it was not regen, not touching brakes. no explanation, just felt like extreme braking. after that it rolled again but motor making noises.

Limped home but power weak. After cooling off it makes this noise when free spinning- at around mid throttle - 66-69 kph range (freewheel goes up to 105kph)

Yes i will likely have to pull motor apart and inspect, but first i wanted to post this, since motor noises can be very distinct, and maybe someone with a lot more experience is familiar with this noise and what it likely indicates...

thoughts? much appreciated. Also, what size 3 jaw puller to use to open up the QS205? this will be my first time working on a "big" motor

 

[Chalo]

You might have magnets unstuck in there, making contact with the stator.

 

[TwisterGripper]

Has an unstuck magnet ever been known to lock up a motor? even for a few seconds until it got crunched up?
would need a big gap to pop out of its seat I would think....looks like im gonna have to open and inspect...

 

[AGS]

I use a 4” 3 jaw puller, but it’s fiddly and I have to use cable ties to keep the jaws together.

I think a 2 jaw puller would be easier.

I have also replaced the KTY 83 temperature sensor with an NTC 10K so I can keep an eye on motor temperature. It isn‘t difficult to overheat these motors if being aggressive on the throttle.

 

[TwisterGripper]

I use a 4” 3 jaw puller, but it’s fiddly and I have to use cable ties to keep the jaws together.

I think a 2 jaw puller would be easier.

I have also replaced the KTY 83 temperature sensor with an NTC 10K so I can keep an eye on motor temperature. It isn‘t difficult to overheat these motors if being aggressive on the throttle.

In a video i watched, looked like a much bigger puller tool...like 8 or 10"... i'll have to do more digging on that.

Funny you mention temperature. the Onyx app is showing the motor temp is NEGATIVE 273 degrees (cold) lol.

 

[TwisterGripper]

Ok update: opened up the motor; bearings are like new, super smooth, magnets are all glued in. no signs of anything scraping around inside the motor, no burned or discolored wires. looks perfect. Im stumped. maybe the noise is just a perfectly normal resonance of some sort and the problem is elsewhere...