Motor noise on a new hub motor

oldgroaner

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Nov 15, 2015
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I have a new Front hub motor that runs smoothly yet as well as the normal hum in operation has a slight but noticeable intermittent "chafing" noise rather like a brake block catching, shut the throttle and the noise disappears completely. It comes in between 10 to 12 mph but goes above and below those speeds.
Is this noise likely to get worse or better, my other Ebike (a pedelec) has never had such a noise.
It isn't very loud, is this a typical situation with some motors?
Also, are these motors intended to be capable of pulling away from rest using the throttle alone? i tried this once and the noise and vibration was such I won't be doing it again!
Advice would be appreciated.
 
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anotherkiwi

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Jan 26, 2015
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My friends front hub motor got quieter with use. YMMV...
 

flecc

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Oct 25, 2006
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The torque is at it's maximum from a standstill so it's best not to pull away on power alone, since it puts a lot of strain on the internal gears which are nylon or similar. The high noise then is an indication of that stress. In addition the consumption then is at it's highest so it saps the range disproportionally.

As another kiwi says, see if it soon beds down and quietens with use before worrying about that other slight noise.
.
 

oldgroaner

Esteemed Pedelecer
Nov 15, 2015
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The torque is at it's maximum from a standstill so it's best not to pull away on power alone, since it puts a lot of strain on the internal gears which are nylon or similar. The high noise then is an indication of that stress. In addition the consumption then is at it's highest so it saps the range disproportionally.

As another kiwi says, see if it soon beds down and quietens with use before worrying about that other slight noise.
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Thank you for that, it's a pity that advice didn't come with the Hub motor!
 

oldgroaner

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Nov 15, 2015
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It is now 11 months since I started this thread, and 1500 plus miles later the noise is still there, and perhaps a little louder, so I will use it and wait patiently for it to get bad enough to strip down, though possibly the simplest course of action at that point being to replace the whole wheel and motor like for like.
 
D

Deleted member 4366

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Different controllers can have a massive effect on motor noise, especially at low speed. Which one do you have?
 

Nealh

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Aug 7, 2014
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Which hub motor is it ? As an aside it could b a faulty side pate bearing that is grinding.
 

oldgroaner

Esteemed Pedelecer
Nov 15, 2015
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Different controllers can have a massive effect on motor noise, especially at low speed. Which one do you have?
Its a Boss
Different controllers can have a massive effect on motor noise, especially at low speed. Which one do you have?
It's a Boss 3648140138 with a boss badged C965A display.
There is definitely something odd as the display has always shown the speed to be actually three times the true speed, when I brought this up with the shop they said the software would allow the true speed to be set!
Also I asked if it could be fitted with a pedelec sensor instead of just the throttle and they said the motor wasn't suitable for that and it would fail.
The motor is Suzhou Bafang BF 1411D155405-6 "Sparticle"
Supplier and fit of the Conversion Electric Transport Co of York
 

Benjahmin

Esteemed Pedelecer
Nov 10, 2014
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I had a similar thing on my Ezee. It would get worse after a long climb and disappear if I turned the power off. I stripped the motor apart, intending to regrease the gears, and found that the bearing mounted in the motor casing was badly gritty. It's been fine since replacement.
 

oldgroaner

Esteemed Pedelecer
Nov 15, 2015
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Finally I got around to stripping the motor on the Brompton. It has covered over 3000 miles and was an absolute breeze to strip far enough to access the nylon gears and check the bearings, I was prepared to separate the rotor and stator, by there was no play in the bearings so this wasn't necessary.
The clutch too was smooth and once I had degreased the gears, all were in excellent condition.
There was no evidence of parts that had been catching, but there was something wrong with the graphite based grease, which seemed to have partially changed into a gel, leaving just a thin powdery coating stuck firmly over the moving parts.
Most of the grease had in fact moved onto the face of the flywheel and down the back of the ring gear.
After degreasing and drying out I applied a lithium grease to all the moving parts and when reassembled it sounded like a brand new unit with no chafing noise.
Apart from an Impact screwdriver, hammer and mallet, grease and loctite for the screws no special tools were required for what was a simple and limited stripdown.
Less than an hour start to finish.
What was surprising was how good all the component parts were after being abused for so long!
These motors are really tough!
 
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