Bafang BBSxx - fault finding and fixes

[Slowrider]

Hello, I just finished installling a new Bafang BBS02 750W kit, and when testing it I think it makes a strange pulsating clanking sound from motor or gear.
See attached video
http://www.youtube.com/watch?v=dxGLE6lLAls&list=HL1397298109

Is this "normal" noise and am I being way to critical or should I be concerned. The kit is super easy to install and I can not see what I could have done wrong so I am a bit puzzeled about this.

I appreciated feedback regarding this.

 

[ziltoid81]

This is not normal....my bbs01 is nearly noiseless.
When driving the tire is louder.....

Thats the point at the time, there are no spareparts for the internal gearing.

Normally we must say "stop bying that motor", cause if the internal gearingwheel is broken, the whole kit is worthless.

For the Bafang hub motors there are very cheap gearing spareparts available......

 

[teslanv]

Mine was making that sound also.

Here is my video:

http://youtu.be/KawJFYswEac

I tore it down, but have not yet found any broken gears. It may have just gotten dirt or debris in the gear housing, so I am in the process of cleaning and regreasing the gears.

The Nylon helical gear had a white grease, which I suspect is a silicone type of grease as opposed to Moly. The final gear had what looks like dark Moly grease. I should be hearing back from lcrewse shortly for guidance on grease type.

Then I will Put it back together and test it out.

Here are pics of my tear-down:

 

[Melbourne]

Mine was making odd sounds also. I tore it down, but have not yet found any broken gears. It may have just gotten dirt or debris in the gear housing, so I am in the process of cleaning and regreasing the gears. I should be hearing back from lcrewse shortly for guidance on grease type. Then I will Put it back together and test it out.

you need to speaker to kepler... very similar to my ticking noise i had on my 350w but your seem to be worst. I fixed my by adding moly grease to ends of the metal magnetic gear and fixed it but kepler said the ends are worn.

Oops ..sorry. Mis-read...you have a new bbs02...sorry.

 

[teslanv]

Oops ..sorry. Mis-read...you have a new bbs02...sorry.

Yeah, my unit was manufactured on 11-27-2013

 

[samsavvas]

Is this "normal" noise and am I being way to critical or should I be concerned. The kit is super easy to install and I can not see what I could have done wrong so I am a bit puzzeled about this.

As others have said, noise from the motor is not normal at all. Should be just about completely silent! Check the main thread for Kepler's experiences with noises and fixes. Maybe take the chain off first and make sure the noise is not elsewhere in the drive train if you haven't already done so. I understand that there are screws inside which sometimes need tightening. Don't be too worried - general experience seems to indicate the BBSxx is a reliable unit if not abused although it sounds to me as though assembly sometimes seems to be a bit lax.

Savvas

 

[Kepler]

Remove the rotor from the stator and measure the diameter of the non drive side bearing journal on the rotor. It should be exactly 8.00mm. Check it for wear. Also check if it has a small orange o ring like on the drive side journal.

 

[teslanv]

Remove the rotor from the stator and measure the diameter of the non drive side bearing journal on the rotor. It should be exactly 8.00mm. Check it for wear. Also check if it has a small orange o ring like on the drive side journal.

Any advice for how to remove the rotor from the stator?

 

[Kepler]

Hold the gear in a vice with soft jaws. Pull the stator away form the rotor. The magnets are strong but it comes out easily enough

 

[Slowrider]

Thanks for all the replays, much appreciated.

From the video that you posted teslanv it seems that we have quite similar noise.
Can somebody please post a video of a motor with normal noise without chain ?

Some questions to teslanv and Kepler : Did the motor you have come with this noise from new or did it develope over time ?
Do you think it is possible to assemble it wrong, I did not have a torqe wrech when thightening the two main nuts and I was thinking that this may lead to misalignment for internal bearings causing noise ?

I am really torn as what to do, my motor is new with 0 km's on it and it should not be nesecssary to breake it down to fix possible faults from factory!? But on the other side it took almost 7 weeks just to get this kit so I would imagne that sending it back for replacement is going to take a lot of time.

 

[Kepler]

In my case, the noise developed over time. It was dead quiet for the first 1000km then started to get noisey. I had 2 problems. the screws holding the final gear were loose but also I discovered some wear on the non drive side rotor shaft. Loctiting and tightening the screw holding the final gear helped but a dab of loctite on the rotor shaft cured the noise completely. I am now up to 2000km and the drive is still dead quiet.

Keep in mind, my drive is an early model and I believe the rotor shaft wear issue has now been resolved (hence my question about the small orange O ring)

However, in your case, I doubt you are suffering the same the problems and more than likely have a QC issue with your drive. So your dilemma is whether to send it back or stip it down. It sounds like sending back would be entail long lead times and uncertain outcomes. With this in mind, I would suggest to open it up and find out what the problem is. The drive comes apart quite easily and if carried out methodically, shouldn't be too hard to find where the noise is coming from.

Over tightening the the 2 main nuts is not going to cause a noise problem. Please carry out the following.

With the chain removed, spin the cranks backwards. Does it spin freely and quietly? (4 or 5 turns after a hard hand spin)

If no, strip down the final drive section of the drive that goes through the bike's bottom bracket.

Next, spin the cranks forward. This will spin both the final gear and the intermediate shaft and gear. Listen for any scraping or unusual tightness. You should get one or two revolutions out of the cranks with a firm spin forward. If not, you will need to investigate further.

Let us know how you go from there.

 

[teslanv]

Thanks Kepler. This is very helpful.
One more question. - What kinds of grease did you use when you reassembled the drive? There are both a white and dark grease in mind.

 

[teslanv]

I think I found the culprit. One mangled orange o-ring. (Shaft still measures right at 8.00mm) - Glad I didn't keep driving the motor in this condition.

And a BIG Thanks for Kepler for steering me in the right direction here. I was basically ready to reassemble the motor, until he mentioned the rotor journal bearing issue.

Where to find a replacement o-ring: -

I know McMaster Carr (http://www.mcmaster.com/#) is a good resource. Looks to be this one? http://www.mcmaster.com/#5233t16/=riqqeg

 

[teslanv]

Just ordered a pack of 50 pcs (smallest quantity MMC sells) of the 8mmx1mm Silicon O-rings. They should be here Tuesday.

If anyone else needs these, PM me, and I'll drop a couple in the mail for you for $3.00 shipped.

 

[teslanv]

I also cleaned off the rotor magnets. You can see in the picture above a dark residue on the very end of the magnets. - I presume this is from when the dislodged o-ring got caught between the rotor & stator. - Explains the "crunching" sound I heard momentarily at the moment my drive developed it's noise. - For the record, I had about 450 miles on my drive before this happened. When I first got it, it was nearly silent.
And as an FYI, when you clean the Rotor, be sure to use a clean synthetic brillo pad, NOT steel wool. Don't ask me how I know this.

 

[teslanv]

I would assume the replacement o-ring should go between the two washers?

 

[samsavvas]

I appreciated feedback regarding this.

Hi Slowrider,

I'd like to make a suggestion. Howabout renaming this thread "BBSxx - fault finding and fixes" (or similar). That way some of the scattered stuff on this topic at the main BBS thread could all be brought together here (I'm presuming this is possible). This would reduce some of the chaos at the main thread and make fault-finding and fixing a bit easier for those encountering problems.

Just an idea...

And with regard to your request for a video of the noise from the BBSxx running without a chain - just think 'silence', or maybe a baby breathing... something like that anyway.

Savvas

 

[Kepler]

I would assume the replacement o-ring should go between the two washers?

No, it goes after the washer but without an O ring grove in the shaft, I think the O ring is not going to be of much use. The latest design rotor now has a grove for the O ring to locate in.



I would recommend you forget about the O ring and smear some Loctite evenly around the shaft before fitting it back into the bearing. I would go for a 641 Bearing mount grade Loctite for this area.

In relation to lubricant, lots of options here but the main point is not to use a petroleum based grease. I use this one http://www.chainreactioncycles.com/...gclid=CKP6g-DP3r0CFQEepQodASMANQ&gclsrc=aw.ds

You should be able to get it from most bike stores.

 

[teslanv]

What's the purpose of the locktite on the bearing? - Is it to "lock" the shaft into the bearing at the base of the Stator?

I also have to ask the question: Where did the O-ring come from on my motor, if there isn't a slot for it?

 

[electrobob]

Did the motor you have come with this noise from new or did it develope over time ?
Do you think it is possible to assemble it wrong, I did not have a torqe wrech when thightening the two main nuts and I was thinking that this may lead to misalignment for internal bearings causing noise ?

I am really torn as what to do, my motor is new with 0 km's on it and it should not be nesecssary to breake it down to fix possible faults from factory!? But on the other side it took almost 7 weeks just to get this kit so I would imagne that sending it back for replacement is going to take a lot of time.

I am in the exact same predicament here :/ In fact, I haven't finished assembling my kit because i'm still waiting for my battery, but by simply spinning the chainring manually I can clearly hear the clicking sound. I was also surprised by how stiff the spinning motion is... is it supposed to be so stiff? I know the rotation of my previous chainring (pre-electric) was much smoother.

By reading this thread, it seems like some lubricant would help, although I'll keep an eye on this thread to see if we get an actual confirmation on the fix. I find it odd that they would ship a malfunctioning kit like that. Its kind of ruining the ''plug and play'' appeal that this kit had.

This is my 1st DIY conversion so I try to take this as a learning opportunity but still, If the problem is too deep I guess i'll have to try and return it, which would suck big time

PS: I am a long time reader of ES but this is my 1st time posting so... Hi guys

 

[Kepler]

Yes, the loctite is to lock the shaft to bearing and ensure it cant spin. It looks like in your picture that the shaft had spun in the bearing. In relation to pulling the rotor back out in the future if needed, I don't think it would be too much of problem as the loctited surface is quite small an would break away quite easily if required.

The O ring was just at the end of the gearing journal. Was a bit of poor design without an O ring grove to locate it.

 

[teslanv]

In relation to lubricant, lots of options here but the main point is not to use a petroleum based grease. I use this one http://www.chainreactioncycles.com/...gclid=CKP6g-DP3r0CFQEepQodASMANQ&gclsrc=aw.ds

You should be able to get it from most bike stores.

I was able to find this at an autoparts store near my house.

http://www.amazon.com/SILGLYDE-LUBE-COMPOUND-8-OZ/dp/B000KXLR5E

Would this work for the metal/nylon helical gears?

 

[Kepler]

I think it would be OK. It says good for O rings so it mustn't be petroleum based.

 

[jateureka]

Kepler, do you know what date code BBS02 had the O-ring groove?

Is this O-ring issue just with the BBS02 or did it happen on early BBS01 versions as well?

Great info!

 

[Slowrider]

I appreciated feedback regarding this.

Hi Slowrider,

I'd like to make a suggestion. Howabout renaming this thread "BBSxx - fault finding and fixes" (or similar). That way some of the scattered stuff on this topic at the main BBS thread could all be brought together here (I'm presuming this is possible). This would reduce some of the chaos at the main thread and make fault-finding and fixing a bit easier for those encountering problems.

Just an idea...

And with regard to your request for a video of the noise from the BBSxx running without a chain - just think 'silence', or maybe a baby breathing... something like that anyway.

Savvas

Hi Savvas, I was actually thinking the same as you regarding renaming the thread.
There is so much good info in the main BBS thread, but quite hard to find as it is closing up on 100 pages fast!
So I will change topic like suggested and we can post bug fixes here.

As to my drive I need more time to check for faults.
I did the crank test backwards as Kepler suggested and it spins about 5 turns quite freely.
But on the crank forward test there is some noise, I will upload a short vid of this later.

Huge thank you to Kepler and teslanv for providing great info and pictures.