Hub motor noise

Eastwood

100 kW
Joined
Jan 13, 2021
Messages
1,470
So I have a single click noise if I hit full throttle or E brake. I’ve been thinking it was my axle slightly twisting in the torque arms but it’s not and the sound has actually gotten louder. The sound is definitely coming from inside the hub motor as I also considered it was the freewheel but it sounds like it’s coming from the opposite side. Maybe a magnet or a bearing but the click noise is only when I engage full throttle or ebreak. If I use even half throttle the sound is not noticeable, strange. Also removed the rear brake caliber to eliminate that and that was not it. The spokes are definitely not making the noise and almost 100% sure it’s inside the hub.

I’ve been hearing it for the last couple of weeks and I thought it was my suspension linkage so I just took all of that apart cleaned and re-greased and then figured out the noise is actually inside the hub motor.

What do you guys think :?:

I know the ultimate diagnose is to open it up but trying to get some insight of what this could possibly be. As mentioned it’s definitely not a single click noise from the axle shifting in the drop outs as I put the bike upside down last night and gave it full throttle and the axle is super sturdy with the clicking sound still there.

Edit: the hub motor is mxus 3K turbo 5T
Around 6 months old
 
Voltron said:
Direct drive motor or gear motor with internal clutch?

It’s a direct drive hub motor.
Mxus 3k turbo
The motor is only about 6 months old and everything seems to be working just great just besides that little click.
 
Eastwood said:
It’s a direct drive hub motor.
Mxus 3k turbo
The motor is only about 6 months old and everything seems to be working just great just besides that little click.

No loose spokes?
 
E-HP said:
Eastwood said:
It’s a direct drive hub motor.
Mxus 3k turbo
The motor is only about 6 months old and everything seems to be working just great just besides that little click.

No loose spokes?
Nope, All the spokes are tight.
 
It might be flexing just enough under full power that the magnet ring is grazing the stator because a magnet is mounted a little sticking out.

How fast is the clicking, like one click per wheel revolution or faster, so maybe a slightly loose magnet clicking every pole rotation?

Or is it just one big click, every time the load is high enough?
 
Voltron said:
Or is it just one big click, every time the load is high enough?

Yes this, but it’s also like a click/creaking noise under full load. Very strange. So I hit full throttle the click/creaking sound occurs and then nothing after that unless I let off the throttle and apply for power again.
Here’s the stranger part but maybe it will help with diagnosing. So having the bike turned upside down being able to spend the wheel freely by hand, I can get the click/creaking noise to occur when the controller is on. When I power off the controller I cannot get the noise to occur no matter how hard I turn the wheel.
 
We can only guess, like you, till you take it apart.

If it really is inside, then my bet would be on it being a magnet that came unglued from the motor.

But its really weird sometimes where a sound comes from on a bike. I've had some really clanky freewheels, and other noises that are harder to track down.
 
dogman dan said:
We can only guess, like you, till you take it apart.

If it really is inside, then my bet would be on it being a magnet that came unglued from the motor.

But its really weird sometimes where a sound comes from on a bike. I've had some really clanky freewheels, and other noises that are harder to track down.

Yeah the strangest part is the back wheel only makes the noise if the controller is turned on. So when I spin the wheel by hand under no load with the controller ON it clicks, then when the controller is off I spin the wheel by hand and get absolutely no click :?:
I will make a video and post a link
 
Eastwood said:
Yeah the strangest part is the back wheel only makes the noise if the controller is turned on. So when I spin the wheel by hand under no load with the controller ON it clicks, then when the controller is off I spin the wheel by hand and get absolutely no click :?:
I will make a video and post a link

When you test it by hand, does it click in both directions?
 
E-HP said:
Eastwood said:
Yeah the strangest part is the back wheel only makes the noise if the controller is turned on. So when I spin the wheel by hand under no load with the controller ON it clicks, then when the controller is off I spin the wheel by hand and get absolutely no click :?:
I will make a video and post a link

When you test it by hand, does it click in both directions?

Yes it clicks in both directions but I have to yank the wheel hard. When I slowly turn the wheel by hand it doesn’t click in either direction. I’m starting to wonder if it has something to do with the axle or maybe the bearings need to be greased. It’s kind of hard to explain the noise it’s like a click but also a quick squeaking noise if that makes sense lol
 
OK it has to be a magnet based on the testing I’m doing. Like I mentioned There’s no clicking noise when the controller is turned off but when the controller is on it clicks I believe because of the magnetic field is stronger so it’s pulling the magnet toward the stater. When the controllers off and I spend the wheel the magnet falls back to its place. Again I have an opened but I can’t see why it wouldn’t be a magnet since it’s directly affected by turning the power on and off.

Now my question is what type of glue do I use to get this magnet back in place? feel like I should order the glue before I even start opening it because based on that testing I would think its the magnet. I’ve literally considered everything from the back wheel to the front wheel at this point lol I think the squeaking sound actually might be coming from a suspension linkage but the actual click is more than likely a magnet. I do have around 7 mL of statorade And I’ve read the controversy with this stuff possibly making magnets come loose but I’m just speculating. could’ve been from heat as I do push this motor but I always keep a watch on the temp.
 
Any higher temp epoxy will work fine. In general, anything that sets slow will take higher temps. Something like JB weld, PC7. Just not the 5 min set stuff.

Don't be too surprised though, when you take it apart and see nothing. It could also be a crack in the cover, or just about anything on the bike.

But if it really can only happen when the windings have power, it could be a magnet that only wants to move when the winding pulls on it.
 
dogman dan said:
Any higher temp epoxy will work fine. In general, anything that sets slow will take higher temps. Something like JB weld, PC7. Just not the 5 min set stuff.

OK thanks. Yeah I was thinking something with a high temp rating. I’ll check out the PC7 👍

dogman dan said:
Don't be too surprised though, when you take it apart and see nothing. It could also be a crack in the cover, or just about anything on the bike.

But if it really can only happen when the windings have power, it could be a magnet that only wants to move when the winding pulls on it.

Well I’m pretty certain it’s a magnet as I can actually hear it clicking up against the case. It was actually my first thought when I heard the clicking noise but I didn’t want it to be true lol So I’ve literally examined the entire bike and when you put your ear close to the hub you can hear it directly smacking on the case

Also if the case was cracked it probably would be leaking statorade.

I will open the motor today to properly diagnose and let you guys know.
 
dogman dan said:
Don't be too surprised though, when you take it apart and see nothing. It could also be a crack in the cover, or just about anything on the bike.

Well it seems all the magnets are secure so I’m still scratching my head here trying to figure out what the clicking noise is. I do see some slight rubbing on the magnets where the stator has struck the magnets, is this normal?
 

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dogman dan said:
Don't be too surprised though, when you take it apart and see nothing.

OK so maybe the stator was not aligned properly and I was getting the clicking noise while applying throttle because it was possibly striking the magnet. Does that sound right? It’s the only thing I can come up with because everything else looks solid and I’ve pulled on these magnets from every angle and they don’t seem to budge.
 
Does the motor make the noise in all gears, or maybe more from 4th or 5th gear on up? I beat my brains out looking for a noise in a motor using a freewheel, not realizing what kind of mickey mouse bearing set up they use. Those gears have NO support out beyond 3rd-4th gear or so, and when worn will make a clicking noise that will make you crazy. Sprockets can look like new, but the freewheel bearings can be shot....

Grab 1st gear and see if it will wobble. A tiny tiny bit is normal. Any more than that can be your clicking issue.
 
Oh boy, I was afraid of this. The rub mark now makes me wonder about the bearings. Particularly the one on the side where the rub mark is. Maybe when you energize, the whole stator tilts a hair, causing the rub and the click? But if so, where's the statorade leak? bearing bad but the seal is good?

Something loose on the stator itself, should be grunting like hell when you run it.

That leaves the freewheel. Its going to be close enough to the motor to fool. But I've seen noises seem to come from all over the bike, only to be somewhere else. Sounds like the BB, but its the freewheel. etc.
 
by dogman dan » Aug 11 2021 5:31am

Oh boy, I was afraid of this. The rub mark now makes me wonder about the bearings. Particularly the one on the side where the rub mark is. Maybe when you energize, the whole stator tilts a hair, causing the rub and the click? But if so, where's the statorade leak? bearing bad but the seal is good?

Something loose on the stator itself, should be grunting like hell when you run it.

That leaves the freewheel. Its going to be close enough to the motor to fool. But I've seen noises seem to come from all over the bike, only to be somewhere else. Sounds like the BB, but its the freewheel. etc.
You would think it had play in it. Look at the marks as they change going around. The bottom of the picture it's hitting harder than the top, how strange. Think it can be warped.
 
AHicks said:
Does the motor make the noise in all gears, or maybe more from 4th or 5th gear on up? I beat my brains out looking for a noise in a motor using a freewheel, not realizing what kind of mickey mouse bearing set up they use. Those gears have NO support out beyond 3rd-4th gear or so, and when worn will make a clicking noise that will make you crazy. Sprockets can look like new, but the freewheel bearings can be shot....

Grab 1st gear and see if it will wobble. A tiny tiny bit is normal. Any more than that can be your clicking issue.

Yeah I checked the freewheel and all is good. Thanks for the info! Makes sense about no support beyond third and fourth gear
 
stator and rotor show signs of contact but as the marks are all the way round I would presume would make continuous grind noise as opposed to a click, however your pictures are very good so was able to zoom in and can see small chips in the magnets possibly caused interference between magnets and stator ,is just a guess and would fit in with the click when energised, but maybe one of the chips is being attracted to magnets then touching stator when turning click once a revolution , maybe check really carefully for chips clean all over and reassemble, have you put motor back together yet be interested if still click after reassembly be nice if was this easy fix anyway :mrgreen:
 
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