Bafang BBSxx, replacement of bearings in bottom bracket

[Karius]

Hey guys!
Now I have adjusted the size of the images of Chewy's new motor. It looks as though it is an oil seal, similar to that used on the drive axles on cars. It would have been interesting to see the seal separately, and not only fitted in the crank. In addition, it had been interesting with a part number and dimensions.

It will be interesting to see when this seal is available as a spare part.

Thanks for the picture Chewy!

View attachment 1

 

[Chewy]

If I'd known at the time I would have taken measurements and pictures of the seal.

It is actually a dust seal and not an oil seal. Like the type used for motorcycle wheel bearings.

 

[Karius]

If I'd known at the time I would have taken measurements and pictures of the seal.

It is actually a dust seal and not an oil seal. Like the type used for motorcycle wheel bearings.

Maybe a stupid question, but can you remember about this sealing was vulcanized in the outer nut, or was it mounted separately like that old silicone sealing?
I hope that a vendor gets the new gasket in stock as soon as possible. Here in Norway it rains too often. This spring has been cold and wet so far. :x

 

[jtrops]

this thread is interesting, and as someone who will be taking delivery of a Bafang crank drive soon I'm wondering if it wouldn't be a good idea to pull the spindle, and put a bunch of grease inside before I assemble it for the first time.

Having never had one in my hand it's hard to tell for sure, but from the photo's it looks like the locknuts on the left side come off, and the spindle should just pull out from the right (with the big reduction gear). The needle bearings look open, and should benefit from a liberal application of grease, and the thrust bearings look like they might get a bit of grease between the races as well. Do you think this would help? As far as I can see you won't hurt the bearings unless you try to remove them.

On removal: Is it possible to remove them, without damage, with an appropriate blind bearing removal tool?

 

[Chewy]

If I'd known at the time I would have taken measurements and pictures of the seal.

It is actually a dust seal and not an oil seal. Like the type used for motorcycle wheel bearings.

Maybe a stupid question, but can you remember about this sealing was vulcanized in the outer nut, or was it mounted separately like that old silicone sealing?
I hope that a vendor gets the new gasket in stock as soon as possible. Here in Norway it rains too often. This spring has been cold and wet so far. :x

The seal was completely separate and I'm guessing a pretty standard size. The lock nuts were both identical, I think the old ones had one thick and one thin ?

 

[Chewy]

this thread is interesting, and as someone who will be taking delivery of a Bafang crank drive soon I'm wondering if it wouldn't be a good idea to pull the spindle, and put a bunch of grease inside before I assemble it for the first time.

Having never had one in my hand it's hard to tell for sure, but from the photo's it looks like the locknuts on the left side come off, and the spindle should just pull out from the right (with the big reduction gear). The needle bearings look open, and should benefit from a liberal application of grease, and the thrust bearings look like they might get a bit of grease between the races as well. Do you think this would help? As far as I can see you won't hurt the bearings unless you try to remove them.

On removal: Is it possible to remove them, without damage, with an appropriate blind bearing removal tool?

Yes that's right, although no need to remove the bearings to grease them. Make sure you tighten the freewheel gear screws while your in there.

 

[jtrops]

this thread is interesting, and as someone who will be taking delivery of a Bafang crank drive soon I'm wondering if it wouldn't be a good idea to pull the spindle, and put a bunch of grease inside before I assemble it for the first time.

Having never had one in my hand it's hard to tell for sure, but from the photo's it looks like the locknuts on the left side come off, and the spindle should just pull out from the right (with the big reduction gear). The needle bearings look open, and should benefit from a liberal application of grease, and the thrust bearings look like they might get a bit of grease between the races as well. Do you think this would help? As far as I can see you won't hurt the bearings unless you try to remove them.

On removal: Is it possible to remove them, without damage, with an appropriate blind bearing removal tool?

Yes that's right, although no need to remove the bearings to grease them. Make sure you tighten the freewheel gear screws while your in there.

Great, that's what I Thought about pulling the spindle without removing the bearings.

I was only asking about the bearing removal to get a better picture of how it goes together.

I'll plan on packing it with grease, and hopefully it will go a few more miles without trouble.

 

[Lurkin]

How frequently do these need to be replaced?

Mines started to make a "grrr" sound when accelerating (not present without the motor assist). At first it assumed it to be these dreaded bearings failing. This has happened after ~3,000 kms and a week of commuting through heavy rain (80km per day commute). But it wasnt constant when it first started... becoming louder. Wonder if something has gotten into the internal gears?

Will investigate further. Any custom tools required to take this apart? (other than lockring spanner for outer locknuts)

 

[Lurkin]

Update.

Removed crank arms, inner spindle lock ring, washer, rubber washer (gouged), more inner lockring, needle? bearing. Removed crank shaft and clutch with corresponding needle. No sign of any rubber o-ring. Perhaps I have the later model.

*shouldn't there be a second metal washer to 'sandwich' the transparent rubber washer to protect it from the lockring (which has gouged it)? Whats it's purpose anyway? EDIT - read more, now understand this is a piss weak attempt by Bafang to keep debris/potentially water out of the thrust/needle bearings. Given the installation destroys them, seems pretty pointless.

Needle bearings and thrust bearings seem pretty dry. Not much lube on them. Not impressed. Perhaps this is the cause of the noise. (recommended grease?)

Appears both grit and water may have gotten underneath clutch cover/reduction gear area. Really needs a gasket or seal there of some description. Will be cleaning and re-greasing clutch gear/motor gear area. Will consider a line of silicon round it when reassembling.

Still nothing seems 'wrong' enough for any noise to be made. Bearings were not disintegrating or anything as others have had. I think a decent packing with grease is in order.

Next stop will be to take the main motor cover off and remove the rest to inspect. Have also re read this thread and there are suggestions of tightening the freewheel screws. Will inspect tomorrow.

 

[Lurkin]

Put battery back on, tested without clutch gear (without taking anything further apart). Motor made the grindy sound.

Took controller off, opened motor case. Removed the motor shaft with magnets on it.

Holy smoke. The inner most end of the shaft (side of the magnets which does not have a worm gear on it) has been rotating without the bearing rotating. Metal filings coat that end...

There is a recession which I assume was where the previously discussed orange o-ring used to live... with no o-ring - long gone.

Looks like I will be contacting Paul about this...

 

[Karius]

Put battery back on, tested without clutch gear (without taking anything further apart). Motor made the grindy sound.

Took controller off, opened motor case. Removed the motor shaft with magnets on it.

Holy smoke. The inner most end of the shaft (side of the magnets which does not have a worm gear on it) has been rotating without the bearing rotating. Metal filings coat that end...

There is a recession which I assume was where the previously discussed orange o-ring used to live... with no o-ring - long gone.

Looks like I will be contacting Paul about this...

That was bad news. Is it possible for you to upload some pictures of your observations, together with engine data and the first four digits of the serial number?

Karius

 

[tomjasz]

Just ordered a 16003RS here: http://lagerkoning.nl/BO639615-kogellager-16003-rs-17x35x8mm

I have new 68MM shafts available again. PM for details.

 

[tomjasz]

USA price $25 shipped.

 

[Karius]

Hey guys!
Does anyone know if the new crank sealing/gasket can be purchased as a spare part?

 

[Lurkin]

Hi Karius,

Anything can be purchased as a spare part. It's just cheaper to use other sources. Frankly, I would be seeing if I could source locally rather than from Bafang. I'm really not that impressed with the quality of their design or their parts now that I have taken it apart. Everything about them screams cheapskate. I've half a mind to put this thing back together and sell it to someone else.

Teslav has some, but you should be able to find them on the interwebs.

To update, Paul came through by providing a replacement 'motor cup' with the motor shaft and hall sensors complete in it. Whilst I rejoiced when I got it, I'm now realising that I still require:-

- Grease replacements elsewhere in the motor because the whole thing needs to be cleaned of metal filings. This will involve removing all grease inside and replacing.
- The white sealant on on the wires from the motor where it goes into the other side.
- Blue loctite to seal the shaft to the bearing
- Consideration of whether I should just replace other bearings whilst I'm at it.

I have requested Paul on more than one occasion to provide me with the types of grease used, which he has not come through with to date. Further, he has not answered questions about the availability of a bearing kit. I was intending to get a price on a list of all bearings within the motor and obtaining say 5x it, so when people want them on here I can just courier it to them. The point was to package/freight them with whatever parts he was sending as a warranty claim. Anyway, that can't happen because questions regarding bearings to date have gone unanswered.

It's been a mixed bag experience. Awesome Em3ev provides warranty claims, but average communication about what was to be provided and when - I worked it out when it arrived! I'm assuming Em3ev doesn't actually respond to the warranty claim and they are conducted elsewhere (i.e. by Bafang). Hence his emails vaguely said 'replacements will be provided' without detailing what they actually are.

 

[Lurkin]

Finally putting this back together.

Just not sure about tightening the two locknuts on the crank spindle. How tight should the inner one be before tightening the outer against it?

Would it be an idea to use two aluminium washers to squeeze the silicon washer, as opposed to squishing it between the locknut (not flat given it has four notches in it) against a flat aluminium washer?

 

[Reymundo911]

Hello!

I know this is an old post. But my bike is making some loud clicking noises on occasion, only when I am pedalling. I suspect a problem with the bearings because I have checked pretty much everything else (I think...).

My question is, are the bearings found here appropriate for fixing the problems described in this thread?
https://lunacycle.com/parts/bafang-parts/bbs02-parts/bbs02-needle-roller-bearing-part-nk1716/

Thanks so much for any help!

 

[neil.b]

If you have a bbs01 or 02 then that should be fine, the HD i'm not sure if its the same. Another thing to consider is that because the needle roller bearing runs straight onto the axle then its best to replace that as well. I recently rebuilt my 02B and replaced both roller bearings, the thrust bearings, the seal and the axle. The real pain is getting the internal lock nut tight without over tightening the main nut and causing the whole thing to bind up. I did this by trial and error leaving the main nut looser than it should be and cranking the lock nut down onto it until its both tight enough so it wont come undone and not binding the thrust bearings up. Also make sure you use the correct grease and that you thoroughly clean all the old grease out, I used bearing grease on the needle roller and thrust bearings in mine. These are the parts I used:

http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-bbs-axle-rubber-seal.html

http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-bbs01-bbs02-kit-needle-bearing-for-replacement-nk17-16.html

http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-mid-crank-kit-bbs-clutch-replacement-washers-lock-nuts-ball-bearing.html

http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts/bafang-8fun-bbs01-bbs02-clutch-lock-nut-spanner-wrench.html

https://california-ebike.com/shop/bafang-standard-crank-axle-68mm/

Hope that helps and good luck.

 

[Reymundo911]

Thanks so much Neil for the fast reply and the great info!

I am still not 100% sure the problem is a faulty bearing and by your description and the rest of the thread I kind of hope that that is not the problem because it seems like a real pain to fix!

For more context, when I first rode my bike I ended up getting caught in a storm, in which I biked 10 km's on a dirt road. I believe my bike started to make this occasional clicking sound sometime after that.
Now, if I press on the brakes and apply pressure to a pedal, I can sometimes hear a very loud click. However when I am riding it will happen once every few minutes, and only when I pedal (not on throttle). Does this sound like faulty bearing behavior? My build only has 300 km's on it!

Thanks again

 

[neil.b]

It may be worth making sure the nut that holds the unit into the bottom bracket shell is properly tight and that your crank arm bolts are properly tight also. Either of those being loose will cause clicking like you described. It would be unusual for the axle/bearings to be giving you trouble with that amount of use unless either it wasn't greased properly at the factory or it has gotten a lot of water inside.

 

[tomjasz]

Thanks so much Neil for the fast reply and the great info!

I am still not 100% sure the problem is a faulty bearing and by your description and the rest of the thread I kind of hope that that is not the problem because it seems like a real pain to fix!

For more context, when I first rode my bike I ended up getting caught in a storm, in which I biked 10 km's on a dirt road. I believe my bike started to make this occasional clicking sound sometime after that.
Now, if I press on the brakes and apply pressure to a pedal, I can sometimes hear a very loud click. However when I am riding it will happen once every few minutes, and only when I pedal (not on throttle). Does this sound like faulty bearing behavior? My build only has 300 km's on it!

Thanks again

You can likely get parts much faster from California eBikes.

 

[mrMikasa]

Hi

I have a problem.

The gear on my Rotor with Bearing (BBS-HD) has been cut off.

How is that possible?

And how do I replace it?
How do I remove the Rotor. The Gear is gone and the Rotor is stuck as a rock.
Where do I buy it from? Most cheapest? And fastest delivery?

BR.

Jens...

 

[tomjasz]

There are. many youtube videos showing how to disassemble.

You'll need a new rotor.

https://california-ebike.com/shop/bafang-bbshd-1000-motor-rotor-replacement/

 

[mrMikasa]

There are. many youtube videos showing how to disassemble.

You'll need a new rotor.

https://california-ebike.com/shop/bafang-bbshd-1000-motor-rotor-replacement/

Too expensive. Already ordered one.

I have already dissembled it, as you can see on my pictures.
Read again.

Show me the video that removes the Rotor (BBS-HD).
And then show me the video that removes it, when the gear has been cut off.
It is stuck and no handle or tool to unplug it.

 

[tomjasz]

Glad you sorted it. It's not often EVERY repair is videoed.
No good deed goes unpunished...