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High pitch whining noise FOC Helical Drive



Well … Mounted them last month and had maybe 10-12 rides (180- 200km). One week ago I recognized the noise and it’s getting worse and worse. :tired_face:


That I have seen, but you said you know that voice and you give that motor max 4-5rides before totally broke.
Was interested if that already happened or if it’s still ok.
Any feedback from hobbyking already?


This is the third video of SK8 motor noise within 1 week and this is the worst :laughing: I didn’t wrote HK yet, good reminder, I prefered riding.

I had 3 rides so far, let’s see…



Check this out. My motor sounded like @Trdolan03 and kept ridding until this new noise.


The motor stil does good enough for speed.


Can’t watch it, is it private?
Change it to “not listed”


Should be fixed now


Damn :flushed:


@Trdolan03 Can you check to see if the cir-clip is obstructed? Does it freely spin when mounted to the motor mount on your gear drive.

@Ethel Yours could of been the same issue. I think you emailed us can you PM your email?


@torqueboards :raised_hands::pray:

This 6374 motor cannot be service by you. I’ve ran it over 100s of miles, used the shit out of it. It’s not fair. I am going To test my new still in box black 6380 motors unless you think I should swap them?

Edit: oddly it did start to make noise when I updated Vesc settings to new FW and increased my motor max for MORE POWER. Could be coincidence


@Ethel You can still send it in and we can try if you want that is.

When did you get your 6380s? You should PM me as we seem to be having an issue with the 6380 Black for our last batch (retainer rings loose). We have some new ones that are in production with the issue fixed. We should definitely get yours fixed. It can be fixed by resealing the retainer ring with epoxy.


Yes the c clip is unobstructed. @torqueboards
I can send both motors in to your guys if you want to test them. I ordered a set of sk8 motors for the mean time.


@rich @torqueboards did you listen to the video?


So this is just on the blacks? I have a pair of the silvers on the way. No issues with those? It will be a minute before I get a build up and running to test and don’t want to wear out “warranty time”

Awesome that you are all over this!


I have those motors in my cart right now.
Curious myself.


Yes if you mean yours in the OP

Once I had a Maytech motor which started with whining noises at higher speed and after some rides it sounded almost like the one from @ethel plus there was some resistance when spinning


Yep :+1:t3:

Mine does what yours does, except Mine is older motor. I hear the pitch noise at certain speed, under or over, noise is gone. However, I kept riding and the sound turned into what my video shows you. :wink:


@Trdolan03 @Sender @Skunk @Ethel Yeah, obstructed C-clip is an issue typically more so for TB Mounts. This is mostly for 6380. The cir-clip is meant to be flushed but I believe, we needed an extra 1mm for 6380s so the cir-clip sticks up a bit. Could be for other setups but I’m not 100% sure, you’ll have to check. You just want the cir-clip to spin with the shaft and not cause any added friction if it’s stuck on a mount or what not. This goes for all motors too and can cause the “noise” you are experiencing @Trdolan03 (one of the reasons).

The fix for this would be to add M4 washers on the motor mount to gap about 1mm so the cir-clip spins with the motor shaft. See video below. I believe, this is what’s mainly causing the retainer ring to be pushed out.

Although, this isn’t the fix for ALL “high pitch whining noises”. This is a possible solution for one.

https://www.youtube.com/watch?v=KjuMGeQHeLg 6374 6380 Motor CirClip

@Trdolan03 - I’d gap it 1mm and try it. You should be good by then. If not, let us know.

@Sender - Mostly, on blacks it seems but make sure that your cir-clip isn’t obstructed. But yeah, we got you covered just let me know and I’ll take care of you either way. If you want to double safe, you can add epoxy on the retainer ring but I believe the issue is caused by this cir-clip issue.

We tested like 20+ motors and for 6380s they all had this high pitched noise/resistance and the cir-clip was the culprit. Once we added the M4 washers to gap it 1mm. Everything was good.

@Skunk - So far everything seems to point to the cir-clip. You can purchase now or you can wait for the next batch which has fixed this issue. Either way now or later we got you covered.


Vendor action at its’ damn finest! Thank you!


I am running @Nowind direct drive which has a hole in the motor mount wider than the c-clip.


@Trdolan03 Ok, got it. I think I read that wrong. I believe, you started an email so we’ll discuss through there.