Bafang BBSxx - fault finding and fixes

samsavvas said:

Hi Folks,

Haven't been to ES for a long while - not through lack of interest mind you - but just lack of time. However I think I need the community's help so here we are! I've just resurrected my old BBS01 250W/36V. It's been in storage for a year or so since last used, now fitted to an Kemper Filibus cargo bike.
https://www.flickr.com/photos/48163544@N02/32749845063/in/album-72157679710115611
The new rear wheel has a brand new Sturmey Archer 3 speed with drum brake. I've just been on a test ride and while the drive, gears, brakes etc all seem to work very well, I've noticed a new noise which I suspect I shouldn't be hearing and which wasn't there when the BBS unit was last used.

I've used a S/A 3 speed before in another bike and I'm aware that they make a very gentle high-frequency ticking noise when coasting due to their multiple freewheel pawls and I can certainly hear this with the new hub. However when I powered up the BBS today - both when I used the throttle and when I used the pedal-actuated drive - there was quite a loud lower frequency 'ticking'. Not a clunking or banging or anything I'd associate with a chipped or broken gear inside the BBS. Just a loud ticking sound that increased and decreased with speed and stopped when just coasting the bike under momentum.

I've eliminated the possibility of chain or any other drive train issues - it clearly seems to be coming from inside the BBS unit (which is otherwise working fine). Doses anyone have any experience with this noise and have any idea what might be causing it. Suggestion and insights much appreciated.

Thanks,
Sam.

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High Sam! Long time no see! I had a wheel built with the same SA 3spd and brake. Never got around to using it. Still waiting for someone to be interested. I've read good things about it. You seem happy with it?

I'de definitely second the lubrication. I check mine and do some cleanup at the beginning of every season. So far we're going into season 4 with our 01's. Under rated little motors IMO.

I used aviation grade grease as someone suggested.

All the best!

Tom

Thanks Tom L & TomJasz,

I will indeed have a go at greasing the insides of the motor's gears. However I had a bit of a catastrophe riding home today after a 15km outing. Starting off from the curb, forgetting the hub was in topgear, I hit the throttle to move away and across the road (awkward to mount and pedal while turning the cargo bike) and promptly busted something in the BBS reduction gear box. Loud 'clack' followed by repeated clattering and jerking as I pedalled across what is a rather busy road! Was able to very carefully ride home with the bike clattering and jerking along on very gentle throttle. Sounds like I've broken something eh?

I've forgotten what the insides of these thinks look like but I suspect I've busted a tooth or two on the white nylon geared freewheel. Or maybe the metal pinion. Are these parts readily available? I'll check EM3ev shortly but perhaps there are other sources people might recommend? Also, I recall a guide somewhere for taking the BBS01 apart. Can someone point me to it please? And I'd appreciate any tips people may have for updating/rebuilding the gear train...

Thanks,

Sam.

samsavvas said:

Thanks Tom L & TomJasz,

I will indeed have a go at greasing the insides of the motor's gears. However I had a bit of a catastrophe riding home today after a 15km outing. Starting off from the curb, forgetting the hub was in topgear, I hit the throttle to move away and across the road (awkward to mount and pedal while turning the cargo bike) and promptly busted something in the BBS reduction gear box. Loud 'clack' followed by repeated clattering and jerking as I pedalled across what is a rather busy road! Was able to very carefully ride home with the bike clattering and jerking along on very gentle throttle. Sounds like I've broken something eh?

I've forgotten what the insides of these thinks look like but I suspect I've busted a tooth or two on the white nylon geared freewheel. Or maybe the metal pinion. Are these parts readily available? I'll check EM3ev shortly but perhaps there are other sources people might recommend? Also, I recall a guide somewhere for taking the BBS01 apart. Can someone point me to it please? And I'd appreciate any tips people may have for updating/rebuilding the gear train...

Thanks,

Sam.

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Everyone immediately goes for the nylon gear, might just be fairly simple. Bruno did a series and a simple google will get good video too. Google bbs02 rebuild and repair and parts, you'll find all sorts of help. Greenbikekit has been one of the faster parts sources. Youll likely need the early plastic gear and pinion GBK has a pretty good brealdown, Lurkin is quite good and dobtless will be one of of the best sources. Brilliant fellow he is.
https://m.youtube.com/watch?v=gSsHYWynC7U

http://www.greenbikekit.com/accessories/bafang-8fun-spare-parts.html

Animalector said:

Check your start current settings

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I did. I increased from 10% to 20% and the juddering become more subtle.

However, after some tests, I noticed that this behaviour is intermittent.
Motor starts well and at about 40rpm there is some "hesitation". It's always in that region.
Most of the time is not even noticeable, but sometimes (on a steep hill) the effect is more pronounced.

Finally, I increased the Keep current a bit and let the start current to 10% as I like a smooth kick.

Start current: 10%
Slow-start: 4
Start degree: 4
Work mode: 10
stop delay : 250ms
current decay: 5
stop decay: 0
Keep current: 70%

For me the smoothness was one of the reasons why I switched from BionX to BBSxx.
I am considering swapping the controller with a BBS02B one or replace the whole unit.

ps: I am running 11S on this controller and with 10S the problem was actually worse.
Voltage sag is minimal, and I use the gears correctly.

samsavvas said:

Sounds like I've broken something eh?

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Just to update things a bit - I took the easy way out! While awaiting a new nylon gear and bearing/seal kit from GBK I ordered a new BBS02 36v motor (set to 350w) from EM3ev. This arrived within a few days - still waiting on the GBK package! The new 36V BBS02 slotted straight in where the older BBS01 had been removed. The only glitch was a much shorter sensor cable which meant I had to relocated the sensor to the seat stay.

I will repair the older unit when I can but for now I'm a happy chappy. Here's a Flickr pic of my new-old restored Filibus and me: https://www.flickr.com/photos/48163544@N02/33099831004/in/dateposted-public/ I'm yet to install mudguards ('fenders' for you 'Mauricans), a longer stem when I can find one and a new front wheel with dyno hub (have the parts, just no time yet). The Kemper Filibus is a fantastic bike - rides really well and it's carrying capacity is proving very handy.

Sam.

Perhaps a trip to SA is in order... hmmm.... unless you are coming to Melbs sometime... 8)

samsavvas said:

samsavvas said:

Sounds like I've broken something eh?

Click to expand...

Just to update things a bit - I took the easy way out! While awaiting a new nylon gear and bearing/seal kit from GBK I ordered a new BBS02 36v motor (set to 350w) from EM3ev. This arrived within a few days - still waiting on the GBK package! The new 36V BBS02 slotted straight in where the older BBS01 had been removed. The only glitch was a much shorter sensor cable which meant I had to relocated the sensor to the seat stay.

I will repair the older unit when I can but for now I'm a happy chappy. Here's a Flickr pic of my new-old restored Filibus and me: https://www.flickr.com/photos/48163544@N02/33099831004/in/dateposted-public/ I'm yet to install mudguards ('fenders' for you 'Mauricans), a longer stem when I can find one and a new front wheel with dyno hub (have the parts, just no time yet). The Kemper Filibus is a fantastic bike - rides really well and it's carrying capacity is proving very handy.

Sam.

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Kemper Filibus, what a nice bike! Of course nothing like it here. I envy the bike. Brilliant design!

While ride today my BBSHD motor took off on it's own at full speed!!! I had been riding over some wet terrain for about four miles on PAS level 4 (set at 30%). I don't have the kill switches set up since I have hydraulic brakes so the only way I could stop it was to hold the start button down until it turned off. I noticed the screen change so that the battery symbol showed empty and blinked and a symbol that looked like the motor was also blinking. Pedaling backwards had no effect in stopping the motor. After allowing the motor to sit for an hour or so it started working normally again even after I hosed it off with fresh water. I am not sure if this is moisture or heat related. All of the external wiring seems to be well insulated and the motor casing tight and fully intact. This BBSHD has over 500 miles and has been used in significant snow conditions and it has been wet many times crossing streams. The only difference I can think of is the water I was traveling through had high concentrations of salt (The Great Salt Lake) thus making the water a much better conductor.

Any ideas? Thank you...

Stuck throttle? Maybe.

Animalector said:

Stuck throttle? Maybe.

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Disconnecting the throttle made no difference.

Seems pretty obvious that water affected it. These motors are not well waterproofed and many have been opened up and found to have rusted on the motor side. I'd open up, grease and use one of the aviation products to water seal the electronics. I do so yearly as routine maintenance.
Boeshield and ACF50 are two good products. I also use some good black RTV silicone to seal where the wire go into the case. This gaskets and grommets aren't doing a good job.

Riding with out a shut down mechanism is pretty careless IMO. Get at least a green button cutoff.

Problem:
I was having an E21 ( e 21 E-21 [for searches]) error. It was coupled with no speed display on the control head and the motor shutting off about every 20 minutes.

Other factors:
When first assembling the kit, I needed to place the speed sensor on the rear wheel of my trike; however, the cable in the kit was not long enough. To deal with this I cut into the speed sensor wire and used cat-5 (network), soldered in, to extend the wire. Cat 5 is solid core.
To add to this, I had forgotten to put the shrink tube on before I started. As such I wrapped all of the solder joints in electrical tape.
In all, it was a crummy job.

Resolution:
I ordered some, proper, three conductor, stranded cable to replace the cat 5. I removed the cat-5 and replaced it. I also remembered to put shrink tubing over all the joints.

Result:
No more error code and the speedometer is working fine again.

A classic example of, "do it right, or do it twice."

Or, "Bogus Builders, we do it nice cuz we do it twice.."

gorndog said:

I know this is slightly off topic, but I've searched everywhere and can't find the relevant info.

Who is the supplier currently making Bafang BBS-02 wiring looms for the CA? I'm hoping to get rid of my LCD and replace it with a CA. (in which case I'm happy to sell it on)

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Reinhard at ebiketechnologies.de

Sam

My BBS02 36V 500w has been running fine for 3 years and I only use it for road use so it has had an easy life. 8)

I have the C963 display and now it permanently on level 1 assist and the display buttons do not respond so can't change assist levels or power off. Luckily when I connect the battery the display automatically powers on at assist level 1. There is no error code showing. The throttle still works so I can use that for more power.

I've checked for loose connections and the battery contacts condition. Not sure if the display module is faulty and don't know if it can be tested with a meter to confirm before splashing out for a replacement.

Has anyone had the same fault or know how to fix it?

Sounds like the buttons themselves are a likely culprit. Might need to replace the display if you can't get it apart and see why they're not working. Explains no error codes, no way for the thing to know it's buttons aren't responding.

If you have a programming cable you could change the PAS1 settings for more power/speed, and at least be stuck in a more appropriate PAS setting.

Hi All,

My BBS01 rotor has gone clickety-clack down the worn rotor track...

Several thousand km's on it (not sure how much). Unfortunately, the problem was gradually developing, and unfortunately I didn't pay enough attention when it started... yesterday I finally tore the thing down and found my rotor diameter on the non-drive side to be 7.4 mm!!!! I'm going to try Locktite as a short-term fix, but this seems like a lot of wear for that remedy to work (see pic)... I'm looking at a replacement rotor or motor core. I need to know what the precise model # is to order one, though. How do I find out the right specs and precise model to select the right replacement part? The serial number is 1409240055.

It seems GreenBikeKit has a good selection of parts in stock, including the right rotor. Can anyone recommend them?

I would true it up and sleeve it with steel, with some bearing retaining loctite compound. You could use a pc of shim stock wrapping the shaft while you wait for new parts if you don't have access to a shop. That would be much better than just loctite. Plenty of meat left on that shaft. If the spiral gear is worn out, I would replace it. Do't let your bearings slop around folks!

Ben Abraham said:

....and found my rotor diameter on the non-drive side to be 7.4 mm!!!! I'm going to try Locktite as a short-term fix,

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For a temporary, and possibly not so temporary if you locate and fix the original cause (is your shaft bent? Are your dropouts misaligned?); I'd be tempted to try QuikSteel

Coat, cover with cling film and insert into bearing while it sets up.

Thanks for the tips comerades! I wasn't aware of QuikSteel; that's an interesting suggestion. Is there any resource that you can indicate for getting shim stock? I have already ordered the replacement from GBK although in retrospect maybe I should have gone with LunaCycles (I've ordered from Luna before when visiting my family back stateside). I have a tube of MobilGrease 28 coming to me express when the week starts for when the rebuilding comes. I've been rushed because this is how I get to work (1 hour each way, from Box Hill <-> Clayton in Melbourne), and my commute is just about the most enjoyable time I have every week so I'm loathe to give it up for even a week.

Here is another source for parts:

https://california-ebike.com/product-category/parts/

The main issue that I see with quicksteel followed by forming by setting in the bearing is that if the rotor is in the stator, the magnets tend to pull it out of true. They are quite firm, and it will be hard to get it set right and straight without them forcing the shaft out of alignment, given that it is worn to the extent that it is, and unevenly so. I'll think about how to do it... but I will also welcome input or ideas.

From what I can work out, Quiksteel is just epoxy by another name. Rather than solve the problem, you would be gluing the inner of the bearing to the shaft. Awesome if it works out, pretty terrible if its too thick and ends up in the bearing or is not strong enough and you are back to square one with plenty of rubbish circulating between the shaft and bearing inner.. hmm. I really like the sleeveing idea.. Would be super practical if one could remove both the bearing and the shaft easily, measure, shim, reinstall.

The assumption has always been with this that the shaft is made of softer material than the bearing inner. It would be interesting to measure the bearing inner diameter of a new bearing and compare it to the wear on one of these failed units. I never did this test, primarily because I had no way to get the bearing out or get an appropriate measurement device into the inner of the bearing whilst in situ. I replaced my shaft with a new one from em3ev - with no luck, the unit was just as noisy afterwards (yes, with plenty of grease etc). I suspect in hindsight the bearing inner was also worn hence the new shaft solved nothing.

Kepler is the pioneer of the solution to this issue, being a Loctite product applied to the shaft and similarly bonded to the bearing inner. I did this as well - be wary, this stuff is like water and you need very, very little of it. Think dipping a cotton bud into it then applying. (I assume) This is indicative of the tolerances being pretty spot on before application - again, not sure how effective this is where the shaft and bearing are both worn given mine continued to be a failure afterwards.

GBK is ok, but I found that, as typically with chinese sites, the prices stated seem very low - until shipping is added. The shipping is the killer and I suspect a number of sites also use shipping to factor or boost their overall pricing. I've often found that the final checkout price including shipping from these sites is not that cheap. Em3ev on the other hand, does have some staff where english is a first language - this makes it a whole lot easier to have confidence that what they are sending is what you want.

And.. who did you buy it off originally and have you enquired as to whether they can fix it on warranty?

Several thousand kilometers probably won't be warranty covered. GBK is OK. Stuff I bought from them was very lw priced and they had BBS01 parts that no one else had. BBS01 was a flop in the USA. Very few of us ride with them. I'd guess Luna and others have never sold one BBS01.

Sadly serial numbers, thanks to poor support from Bafang are useless. Typically one must disassemble and measure or ID parts by markings. GBK does the best job of identifying some BBS01 parts.

California eBikes has a great selection, but again not a lot of BBS01 stuff. You could try dougATcalifornia-ebike.com

His selection of BBS02 and BBSHD parts is complete. If not listed, enquire by email.

Shipping from USA to much of EU and the rest of the world can be as high as those China sources. And the shipping is not padded.