Ncm Moscow motor starting to become very noisy, should I worry?

-sandro-

Member
I own the NCM Moscow standard edition since 2019 with 10000km on it today.
A few days ago after a MTB ride at low speeds on a very steep trail it started to become more noisy, especially at high currents/low speeds (below 10km/h), it doesn't start that noisy at the begging but once you ride it a lot, I suppose once the temperature goes up.
I'm aware this motor is not made for this kind of rides, you have to avoid using high levels if you don't get any speed gain to avoid overheating. It wasn't a particularly hot day and the steep sections were about 2 minutes each (7km/h average) for about 3 times.
Weird thing is that it wasn't the first time I did this, over the years I did this many times with same struggle (you can hear it struggle) but never ended up with the weird noise afterwards.
I'm not sure how the motor is made but it's possible I fried some internal parts causing the noise?
Anyway I think the motor is "about to die", could last "forever" but the noise sometimes is really bothering, but still works just fine.
Probably some maintenance could work (bearings oil?) if that's necessary but I can't do it, and I asked many bike shops and they don't know how to do it and won't dare to open a motor they don't sell.
NCM offers new motor for €120 but you need to mount on the wheel and reattach every single spoke. I'm not sure if I can do that.
 
I'm guessing that your planetary gears are starting to wear out.
They are replaceable but getting just the gears from NCM might not be possible?

What you could do is buy a new motor and just swap the internals. That way, you reuse the outer motor housing with all the spokes connected and don't have to respoke the wheel.

Normally, the outer motor housing is still in good shape and it's just the plastic nylon planetary gears (and their bearings) that are worn out.

This is a video that shows a motor core replacement for a Voltbike.
Your Das-Kit motor should be almost identical.



I'm just guessing that your planetary gears are on their way out, but if they are starting to go, it's best to replace them or the motor guts before you damage the toothed splines in your outer motor housing.

You can also replace the wheel bearings in your hub with the ones from the new motor.
 
Hi, seems pretty easy to do probably much easier than respoking, at least for the planetary gears. They also sell the wheel entirely even though that is just a waste of materials.
 
Another question, NCM said they could ship this without the case and this requires to remove spokes as well. However according to the video it doesn't look like you need to, am I right?
 

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That should install in your old motor.
Your current freewheel will have to come off your old motor core and that requires some special tools.
Once the freewheel is off, you can get the motor end plate off to swap onto your new motor core.

There is a REALLY good chance that all you need is the planetary gears if NCM can sell you just the gears.
You won't know for sure what's wrong with your motor until you open it up, but the planetary gears are described as "wear items". The rest of the motor can last "forever" unless it rusts out or overheats.
It would be good to replace the wheel bearings while you have it apart, but the motor core doesn't look like it includes the bearings.

Apparently the Das-Kit motor is a rebranding MXUS motor, and there might be some differences between it and the Bafang motor in the video.
The planetary gear set may have a C-clip holding it on the motor shaft, or something like that, but everything should come apart (a hammer may be needed, as shown in the video.)

These are the freewheel removal tools that I have,.. (I haven't used them yet.)

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They are cheap crappy tools, but the chain whip should work fine.
I would never use this freewheel socket though,..

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It's a piece of crap that they painted black to make it look like hardened steel. 😂

That thing would snap and could leave the part of the tool broken off inside the freewheel.

Get a proper Park Tool freewheel remover for that job. They come in a few different sizes and dimensions depending on the freewheel that you have.

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It would probably be a good idea to take your motor apart to see what's going on inside before you buy anything.
If the splines/teeth are damaged in the outer motor casing, you're going to need a whole wheel, or a whole motor that needs to be fitted with spokes.

But there's a REALLY good chance that all you need is the planetary gear set if you can order just that part.
 
,.. NCM said they could ship this without the case and this requires to remove spokes as well.

That's not correct.
The spokes don't need to be touched to install that motor core.
You'd think that the people at NCM would know this.

Maybe you should send them a link to that video so they can learn how their motor is put together. 😂
 
From that video doesn't look like you need to remove the freewheel, the freewheel is attached to the other cover and then the motor core is just attached by compression. So basically I could just replace the entire set all together with no special tools.
I see all this from 10:20 in the video.
 
From that video doesn't look like you need to remove the freewheel, the freewheel is attached to the other cover

YES !!
You're right !
I didn't notice that.

That all means that swapping your motor core should be EASY, as long as nothing is seized on the shaft.

Keep in mind that I haven't done this myself, but I think that I know what I'm in for when it comes time for me to do it.
AND Das-Kit uses MXUS motors not Bafang, and I don't what the differences are.
I'm inclined to think that they will be almost exactly the same, but keep in mind a C-clip on the shaft or something before you take the hammer to it. 😂
Bearings may have a C-clip too?? (My car has them.)


Keep in mind too that you can pound the Hell out of the old motor core, or clamp it hard with a vise because it's being replaced. Just don't damage anything that you need to reuse.

A sledge hammer could come in handy, and maybe even a blow torch to heat things up if they are being stubborn. (but don't cook anything that you need to reuse, like the grease in bearings.)
 
I just remembered that the motor cable on my Das-Kit (MXUS) Motor comes out of the motor on the brake rotor side.
The Bafang motors have the motor cable coming out the opposite side through the freewheel.

I don't know if or how that would make any difference on how it's assembled?


Coincidentally, I found out that the motor firing order is reversed for my Das-Kit motor.
Probably because if the cable goes in the opposite side, the armature has to spin in reverse?
 
I'm sure many of we Das-Kit owners would be interested in how this works out....as we likely will deal with it at some point. If you have time, maybe take some pics along the way to share? If worse comes to worst and you need to relace a new motor into your wheel, I'm sure you can do it. I had no experience doing that, but succeeded in relacing 2 wheels myself. A bit time consuming but not rocket science , with help of course from the University of YouTube.
 
Wait, things are starting to get "messy". Not sure if all being on the opposite side changes anything. I would like to see someone that opened this motor already. Probably someone has a video or pictures already?
 
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