8fun motor developed knocking noise

[KirstinS]

Hi all

My 8 fun motor ( bought from uk folk) has overnight developed a loud knocking noise

The wheel is silent when rotating without power but as soon as I hit the throttle there is a knocking noise. So it can't be the wheel/ brakes etc - had to be the motor itself


The frequency of the knock is directly proportionate to the speed ie slow speed gets slow knock, fast speed gets rapid knock

Any guesses here ? And am I doing further damage by issuing it

I have never had issues with motor so have no knowledge . I've never taken one apart and I don't have the tools to do so

Thanks

 

[trex]

does it knock when you apply power and the wheel is off the ground?
If you can hear this, then it's possible that one of the cogs in the gearbox has a damaged tooth.

 

[KirstinS]

does it knock when you apply power and the wheel is off the ground?
If you can hear this, then it's possible that one of the cogs in the gearbox has a damaged tooth.

Yes, the knocking is highly regular , only when power is applied and is the same under load or no load

Gearbox cog you reckon then ?

 

[trex]

you won't know for sure until you take the lid off.

 

[KirstinS]

Not got the tools to get into it. And even if I did not got spare parts. Or find a supplier - BMS don't stock

I've had it a while - time for a new one maybe and keeping running this until it dies

 

[johnc461165]

I had the same problem it was caused by a screw dropping out inside the motor, refitted it with loctite and treated all other screws 3 of which were quite loose that was about 2 years ago. no damage done and no further trouble, you only need a phillips screwdriver and an adjustable spanner. Wish you were closer I would do it for you.

 

[KirstinS]

I had the same problem it was caused by a screw dropping out inside the motor, refitted it with loctite and treated all other screws 3 of which were quite loose that was about 2 years ago. no damage done and no further trouble, you only need a phillips screwdriver and an adjustable spanner. Wish you were closer I would do it for you.

Ahh interesting - so looks I'll have to have a crack at getting inside it over the weekend

If it's just a screw then easily reparable !

 

[Cyclezee]

Cyclezee can supply an 8Fun BBS01 250w 15Ah motor only for £165 including delivery within the UK maniland, for elsewhere there would be an additional delivery cost.

The motors are brand new and unused.

 

[KirstinS]

Oh dear - after my 15 mile daily return commute it sounds horrendous - still only on power. Can't imagine this is a screw. It feels more like teeth in gears going one after another

 

[KirstinS]

Cyclezee can supply an 8Fun BBS01 250w 15Ah motor only for £165 including delivery within the UK maniland, for elsewhere there would be an additional delivery cost.

The motors are brand new and unused.

Thanks but I'm on hub motor - the bbs won't fit my Bottom bracket

I've added a front 350w Bpm2 to my BMS battery order

 

[Cyclezee]

Thanks but I'm on hub motor - the bbs won't fit my Bottom bracket

I've added a front 350w Bpm2 to my BMS battery order

sorry twice over, just assumed it was a BBS01.

It does sound (no pun intended) like the planetary gears which unfortunate but not terminal.
As Trex said taking the motor sideplate off to investigate is the thing to do.

 

[johnc461165]

The best description of the noise i had was it sounded like a football rattle, I think the gears if that is your problem are available from Woosh or

http://www.aliexpress.com/store/group/easy-broken-parts/612941_211853776.html

 

[KirstinS]

Ok so I took off the three Phillips screws and a metal plate

How to I get any further - do I need a special tool ?

 

[KirstinS]

Also the other side has no screws. Here

 

[johnc461165]

Your motor is different to mine, here is a strip down video for your motor and a tool will be required.

Here is the tool if you wish to go that far,after studying photos of your motor and others on the web the internal build is different to mine which makes me agree that the noise is most likely caused by the gears. http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-8fun-bldc-hub-motor-opening-wrench.html You will need to click on the utube box to get the video to play

 

[Tubamanandy]

Thanks for putting that video on - really helpful

 

[KirstinS]

Your motor is different to mine, here is a strip down video for your motor and a tool will be required.

Here is the tool if you wish to go that far,after studying photos of your motor and others on the web the internal build is different to mine which makes me agree that the noise is most likely caused by the gears. http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-8fun-bldc-hub-motor-opening-wrench.html You will need to click on the utube box to get the video to play

Great find , thanks very much. Really helpful

I think I might have a crack at making an opener tool. My bpm2 will be here
in about 2 weeks - I hope anyway so I can get back on the road with that

I can try to make a tool and if the problem is the gears then I need to find a supplier. Not managed it yet as bms and greenbikekit both don't stock. Neither do 8fun uk

I am def up for attempting to fix. It's all great learning for next time

If I find a supplier I'll posit here - if anyone else finds first then I'd be most grateful
Thanks again Kirstin

 

[johnc461165]

I am sure that someone on here got the clutch and gear assembly from Woosh not long ago.

 

[johnc461165]

Third post down on this link, posted in June this year. http://www.pedelecs.co.uk/forum/threads/bafang-8-fun-rear-hub-clutch-needed.18003/

 

[KirstinS]

Ok thanks john - just need to get the cover off then. Will try to make something today