Help with troubleshooting defect

[Danishblunt]

Hello everyone and thank you for having me!
I was troubleshooting my e-bike and am wondering what is going on with it. Here is the problem:

This noise happens when the motor has to work a lot, either from stand or when the bike has to work it's way up. When already riding, the noise dissapears.

It's an ancheer AM001907, I already did quite some troubleshooting and have a suspicion, however I would love some input from more experienced guys.
1.) At first I thought it had to be the planetory gears, I opened the motor and they looked mint after some cleaning. Nothing broken, no real signs of usage.
2.) Then I figured, oh hey, it must be broken hall sensor/s, but nope. Measured all hall sensors and they switch perfecly fine from 0 to 5v.

I'm at the point where I think it's possibly the controller making a ruckus. I have the controller in 48v mode and it caps at 15A, while my battery could provide up to 25A, so my suspicion is that the mosfets are degraded due to me most likely pushing the max out of the poor controller and now it starts to mess a little with the power delivery causing this odd effect under high load, that being said, maybe you guys know something about these generic motors that I don't. I'd prefer not to purchase a new controller due to the trouble of probably having to solder wires due to connector mismatches.

regards dB

 

[Danishblunt]

Update:
At this point I'm quite convinced its the controller. Today is a rather cold day and got to the shop with the bike without any noise coming from the motor. Quite certain that the mosfets or other components are simply degraded to the point where to much heat will make them perform worse than they should. Ordered a new controller + display, gonna update on the status once they arrived.

 

[Danishblunt]

I replaced wires with thicker better ones, cutting out the sensorboard as I ran sensorless anyways. Soldered new connectors to have an easier time doing maintanance and unmounting the engine. I also isolated naked copper wires to make sure the phases wouldnt be affected by it. Even through all that, still grinding noise.

After working on it and troubleshooting for days I finally found the culprit. I never heard of a case like this before, turns out the problem was actually between the magnets and the inner tube holding the copper wires and whatnot. In the outer tube which holds the magnets there was some metal dust and other small junk that has seemed to found its way into the hub. I assume what happened was that when i used to much power it would gather the dust into a lump causing the grinding sound only on high load.

Even tho it seems I wasted tons of time replacing cables, nylon gears and isolating the copper wires, I have to say the hub runs more efficient, faster and with better acceleration. I can recommend modifying your hubs for the performance and efficiency boost.