Brand new hub: Unpowered rubbing noise!

Can anyone diagnose this rubbing noise?

I tried searching the forum to see if anyone has had a similar problem, but all I came up with were disc rubbing issues.

http://youtu.be/mFqGorTXYVo

[youtube]mFqGorTXYVo[/youtube]

Here is an out-of-the-box hub motor. I placed it to my torque arms and rotated the wheel. When the wheel reaches a certain position, during rotation, a rubbing noise is heard. This noise is more prominent on the freewheel side. The noise can be recreated in the opposite direction and is consistent at the same wheel position. This noise was also replicated in a vice holding the wheel in a horizontal position.

Probably a wire isn't tied down inside, and is rubbing on the cover.

It's a bit hard to hear the noise on the video but it sounds more like metal on metal contact. That is most likely due to misalignment between rotor and stator, i.e. the rotor laminations are rubbing against the magnets. I certainly wouldn't power it up and contact wherever you got it from.

I'd pop the cover off, and look for something obvious rubbing like a untrimmed zip tie end or a corner of the plastic insulator common between the stator and the wiring. Then look at the stator itself and see if there is a rub mark where a high spot hits the magnets. Look for other obvious faults, like a bad bearing too.

If the vendor is in china, well, you know.

OK thanks for input guys! Good thing I checked before I put juice into the hub.

Fortunately, I got the motor from e-bikekit.com about a week and half ago.

I want to pop the motor out to see what the problem could be but I don't want to void my warranty.

I wonder if they will give me permission to pop it off without voiding my warranty to check if its the stator rubbing or a zip tie. Unfortunately, I am afraid its the former due to the metal on metal sound, but you never know.

I will keep you updated.

Oh hell yeah, talk to them then. Not hard to send it back to there from where you are. I just clicked on the vid and never looked at the title.

Jason should be pretty good about getting back to you.

Does sound like something under the cover.

Agreed! That’s exactly the sound it will make if the wires are rubbing or if the axle is misaligned (difficult though possible). I recently rebuilt both of mine: One went together flawlessly, and the other I had to pop open and redo (and got it right on the 2nd try).

Work it out with Jason on how to proceed.

If you end up popping the cover on your own, use a gear puller with jaws like the one below.



Best of luck, KF

Ok, well Jason got back to me but the response was not what I expected. I sent him the vid and also asked if I should send it back under warranty or if he will let me pop it open to see inside (given that I can maintain my warranty after doing so).

He responded that nothing is broken and not force a geared motor backwards. Just to put it together, power it on and go.

Just noticed that he sent another email after that saying that it is a direct drive motor and nothing was abnormal with it. Once again he said I can power it on and go.

Not sure what to do right now. I know this sound is not normal. So I just sent another email noting that this noise is not normal and have confirmed this with other people who have had the same motor. I also asked again if I can pop it open with his permission to take a peak inside to see what the deal is (without voiding my warranty) or if he just wants me to send it back to him. We will see what he says...

Keep you guys updated.

sounds to me like one of the little bamboo strips is loose and twanging a sidecover rib?

Doubtfull that anything really harmfull is going on in there, but I'd be popping it open to confirm that now. Could be hes got a cratefull of motors with a bit of insulation card rubbing now, and he knows what it is, that its harmless.

If you are anything like we are, you will never use the warranty anyway. I'd just pop it open and take a peek. You should be able to see if you need to zip tie down a wire.

Your video sounds like the rubbing is on about a ¼ turn. Mine was about ½ turn, and in the few rotations before re-inspection, it was enough to abrade ½-way through the electrical insulation of the HE wires and prompting the rework and replacement of the HE sensors et al, resulting in success on the second attempt.

While we can only guess at the cause of the problem, there are really only two clear choices going forward (aside from doing nothing) and that is to replace the unit or inspect. Relatively speaking, hub motors are inexpensive to replace or to fix. However they can be a little bit of a time sink. Regardless of which path you elect to take, I think it can be candidly said that we are rooting for a positive outcome.

FWIW, I depend less on concern for warrantees unless the product is grossly flawed. My Hex had a complete diametric opposite approach and nitpicked over every faceted detail until the object or service was perfect – and it drove her to be neurotic and inflexible. Someone famous wrote a phrase (or words to the effect) that made a lot of sense with regard to Life’s challenges: In a stiff wind, a rigid tree can fracture and break; it is better to bend like a willow for the path of least resistance is often best. Summation: Near as I can tell, warrantees do not cover cost of shipping & packaging - or more importantly your time fussing about. Therefore… if you can fix it yourself, go for it. There’s lots of knowledge here on The Forum that can help if you get stuck. :wink:

A little Zen from the peanut gallery, KF

the world is your oyster. or hub motor. :lol:

crack it open.

might change your life.

Jason is awesome! He said I can take a peak inside without voiding the warranty.

He said it could be a small shard of metal or something caught in there or maybe a bad bearing in one of the side covers. I'm thinking its a fairly simple fix. Probably just a wire or zip tie rubbing.

Keep you updated.

Twice I had bub motors that were making a rubbing noise. First it was a phase wire rubbing on the rotor and I was going to upgrade the phase wires anyway. The second was rubbing very lightly and i couldn't find the cause of the noise, until a hall sensor broke loose and spinned between the stator and the magnets. ééthat was a mess to clean :wink:

Take the poll and see who has the best answer, before the motor is opened...

http://endless-sphere.com/forums/viewtopic.php?f=5&t=42638

never thought of the dead animal. i'm in for that...

Sorry to disappoint, no dead animals were found. :lol:

It was insulation on the hall sensor wire rubbing on the casing.

Details here: http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=41331&p=638131#p638131

finally we can now sleep at night. :lol: