Bafang BPM Old Style Clutch - where can i get one?

dylan

Finding my (electric) wheels
Oct 12, 2008
9
0
hi Guys
I have an old Bafang BPM 48V500W Rear Driving - RPM : 328 from BMS Battery
the motor runs ok but I believe the clutch is faulty
you have to pull away very slowly otherwise the motor makes a loud screeching / clicking noise
it fine once its up to speed
I opened up the motor with the special tool took out the clutch, cleaned & checked the 3 white plastic gears (all ok)
re-greased the gears & refitted everything & it still has exactly the same fault
I can't find anyone selling the correct replacement clutch (please see attached pictures)
its the older style clutch with the 4 key slots in the central shaft
I can only find the new style clutch with the 1 key slot online to purchase
does anyone have a clutch to sell or can you tell me where to get one?
Thank you in advance
Dylan
 

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KirstinS

Esteemed Pedelecer
Apr 5, 2011
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Brighton
Otherwise Alixpress or BMS battery?

Edit - Nope can't find anything might be worth an email to BMS?
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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Have you checked the side plate sealed bearing for rough rotation to rule out a bearing screech ?
Turn it with your fingers to see if it feels notchy or rough also the same with the planet gears they can be replaced.
The 4 key way clutch is obsolete now and was replaced in 2014 or so.
 
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dylan

Finding my (electric) wheels
Oct 12, 2008
9
0
thank you for the replies.
it's not the bearings, definitely the clutch
I have emailed BMS Battery, waiting a reply
if anyone knows where I can get an old style clutch I would be most greatful
thank you
Dylan
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
You could ask the question on ES forum to see if an answer comes up
or
you could try taking a new single keyway clutch to an engineering machine shop and see if it is possible for them laser cut/mill out three more keyways, using the old one as a pattern to copy.
 

Woosh

Trade Member
May 19, 2012
20,213
16,815
Southend on Sea
wooshbikes.co.uk
there are lots of variants of the clutch units on the BPM, 1 key, 2 keys, 4 keys and some don't fit even when they have the same number of Woodruff keys.
Send it to Southend if you are stuck.
 

Jackytwoshoes

Finding my (electric) wheels
Mar 29, 2019
18
0
I had a good experience getting parts for my Bafang hub from Greenbikekit. Just send them all the details and they might be able to to help. It's worth being specific about size of clutch, size of gears, number of teeth etc..
 

dylan

Finding my (electric) wheels
Oct 12, 2008
9
0
You could ask the question on ES forum to see if an answer comes up
or
you could try taking a new single keyway clutch to an engineering machine shop and see if it is possible for them laser cut/mill out three more keyways, using the old one as a pattern to copy.
 

bugsy

Finding my (electric) wheels
Jun 12, 2013
5
3
hi Guys
I have an old Bafang BPM 48V500W Rear Driving - RPM : 328 from BMS Battery
the motor runs ok but I believe the clutch is faulty
you have to pull away very slowly otherwise the motor makes a loud screeching / clicking noise
it fine once its up to speed
I opened up the motor with the special tool took out the clutch, cleaned & checked the 3 white plastic gears (all ok)
re-greased the gears & refitted everything & it still has exactly the same fault
I can't find anyone selling the correct replacement clutch (please see attached pictures)
its the older style clutch with the 4 key slots in the central shaft
I can only find the new style clutch with the 1 key slot online to purchase
does anyone have a clutch to sell or can you tell me where to get one?
Thank you in advance
Dylan
Hi Dylan,
Try this site.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,882
8,517
61
West Sx RH
Great find .
 

Charliefox

Esteemed Pedelecer
Feb 11, 2015
324
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Culloden Moor Inverness
I had a good experience getting parts for my Bafang hub from Greenbikekit. Just send them all the details and they might be able to to help. It's worth being specific about size of clutch, size of gears, number of teeth etc..
No chance as they only sell the newer one slot clutch. I will have a similar problem if any of the 3 balls in it get damaged. And I would have to grind away the rivets on the outside cover to get even that far! In my case the shaft is the longer version, about 10mm and the available one slot replacements are only 3mm or so. Sad we have such a short production period. My Bafang CST rear hub only came out in 2012? and the clutch was changed only 2 years later!
 

Jim6146

Just Joined
May 9, 2024
2
0
I'm also having the same issue with my 2012 ebike. The clutch has failed exactly as described above. It's the same Bafang 8FUN, 42Teeth, old style clutch with a 4-key slot instead of the more common one key. I cannot find this part. @dylan , Did you have any luck finding a replacement clutch? What was your solution?
Thank You, Jim
 

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,560
3,053
Telford
Bafang hub motor clutch/planetary gear set for Bafang H610, H620, RM G070, 8FUN BPM, 8FUN CST hub motors-greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com

"The clutch has two versions, the old version has 4 key slots and the new version has only one key slot, please check your own motor clutch before making the order. By the way, the new clutch can be used for both BPM motors or Bafang CST motors(produced after 2014)."

I'm not too sure whether that's true. I'd need them in front of me to be sure. I know I have one clutch (your type I think), but not sure if I have the other to compare. I'll look tomorrow if I remember.
 

Woosh

Trade Member
May 19, 2012
20,213
16,815
Southend on Sea
wooshbikes.co.uk
Bafang hub motor clutch/planetary gear set for Bafang H610, H620, RM G070, 8FUN BPM, 8FUN CST hub motors-greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com

"The clutch has two versions, the old version has 4 key slots and the new version has only one key slot, please check your own motor clutch before making the order. By the way, the new clutch can be used for both BPM motors or Bafang CST motors(produced after 2014)."

I'm not too sure whether that's true. I'd need them in front of me to be sure. I know I have one clutch (your type I think), but not sure if I have the other to compare. I'll look tomorrow if I remember.
There are a few versions for the key on the axle. OP should post some close-up pics. I may have what he needs.
 

dylan

Finding my (electric) wheels
Oct 12, 2008
9
0
I'm also having the same issue with my 2012 ebike. The clutch has failed exactly as described above. It's the same Bafang 8FUN, 42Teeth, old style clutch with a 4-key slot instead of the more common one key. I cannot find this part. @dylan , Did you have any luck finding a replacement clutch? What was your solution?
Thank You, Jim
Hi Jim, I replaced the whole motor wheel, less messing around
 

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