Bafang BBSxx - fault finding and fixes

[dumbass]

Hi

Regarding noises from BB and internal crank gearing.

I am looking into installing a grease nipple on the freewheel gear housing to ease re-lubrication of the freewheel/pinion gears.

Great info. Your idea is an idea used by some Ezip/Izip riders to help reduce the gearbox noise. Of course in their case all the gears are steel and start out noisy. So it's just a question how noisy they will be. I've put many hundreds of miles on Ezip bikes and motors and while I did grease them on a rare occasion I never went the grease fitting route. My concern was; "where is all that grease really going?" In the case of the Ezip motor there's only place for it to go.....into the motor winding. Everything in the gearbox is sealed except where the pinion gear comes out of the motor. So when grease is pumped into the gearbox it can be forced into the motor winding. It can help by having a relief port to reduce this problem. There is a fitting that is made with small pins. The excess grease is forced out between the pins but keep dirt and water from coming in.

I've not fully disassembled the Bafang drive so my question is; if you installed a grease fitting on the Bafang and happened to pump in a little to much grease on the Bafang drive where would the excess grease go?

Thanks,

Bob

 

[NFN01]

Hi

Regarding noises from BB and internal crank gearing.

I am looking into installing a grease nipple on the freewheel gear housing to ease re-lubrication of the freewheel/pinion gears.

Great info. Your idea is an idea used by some Ezip/Izip riders to help reduce the gearbox noise. Of course in their case all the gears are steel and start out noisy. So it's just a question how noisy they will be. I've put many hundreds of miles on Ezip bikes and motors and while I did grease them on a rare occasion I never went the grease fitting route. My concern was; "where is all that grease really going?" In the case of the Ezip motor there's only place for it to go.....into the motor winding. Everything in the gearbox is sealed except where the pinion gear comes out of the motor. So when grease is pumped into the gearbox it can be forced into the motor winding. It can help by having a relief port to reduce this problem. There is a fitting that is made with small pins. The excess grease is forced out between the pins but keep dirt and water from coming in.

I've not fully disassembled the Bafang drive so my question is; if you installed a grease fitting on the Bafang and happened to pump in a little to much grease on the Bafang drive where would the excess grease go?

Thanks,

Bob

Hi Bob

The grease works its way around the sides of the freewheel gear and behind it also visible on the inside of the plastic gear cover. I know this from experience as I have
done 3 full strip downs for clean, inspection and re-lube.

A grease nipple would have to be located just past the pinion gear and the grease would be pumped in while very slowly rotating the crank for 1 revolution.
When running, the meshing of the two gears forces the grease out and the teeth of the freewheel gear pick some of it back up, but over time the grease ends up being forced around the sides and behind the gear and on the inside of the cover.
The more grease you pump in eventually ends up filling up the housing.
This is the reason for me fully degreasing everything on a full strip down Every 500-600 miles. You can end up with quite a large dollop of excess grease removed
during the de-grease. Even after this short distance but the overall result is the you can keep everything well lubricated and relatively quiet when running.

I'm also looking at other ways to lubricate these gears including a circulatory oil based system and a method of transferring the excess grease back into the teeth of the freewheel gear as it rotates. If I can come up with something I'll post it here.

N

 

[bono]

I opened the motor yesterday – this is how it looks inside… after less than 1000 miles since the last repair… in flat terrain and no abuse. There is something wrong with this motor.

http://imgur.com/a/dcmhA

 

[speedmd]

Are those missing teeth circled? Way too dry IMO.

If you have some feeler gauges and a dial indicator, you can measure backlash and check for play in the shafts while it is apart. Regardless, both shafts/ gears / bearings will need to be replaced assuming the cases are machined correctly or not bagged out /damaged from running loose now. It will take away the guess work in one shot. Don't you hate it when things go bad!

 

[bono]

Yes, those are missing teeth. Do you have any idea what can cause that kind of damage after less than 1000 miles? I accept that things break ) But either I have too much expectations from Bafang motor, or a couple of repairs withing one year and 2800 miles is too much.

 

[speedmd]

Missing teeth.... Must have rev'd it up and dumped the clutch. Hoping you could tell us what happened. :? Most likely Soft gears.

I am with Tom on this one. This should not be repaired but completely replaced. Don't waste any more time with it.

 

[bono]

I am completely honest with you! I am interested only in a reliable bike to get to my work.

I am riding this bike VERY soft. This is my commuter, no playing, just counting on reliable ride. 98% of the time I am riding less than 25 mph. No off-road.

Just a though - I am using only throttle (no paddle assist), but I am mostly paddling at the same time. Again, when there is small uphill, I am decreasing the power and paddling harder to make the work for the motor easier. Would paddling cause some kind of wear in the gears?

Profile of my commute

 

[alfantastic]

Yes, those are missing teeth. Do you have any idea what can cause that kind of damage after less than 1000 miles? I accept that things break ) But either I have too much expectations from Bafang motor, or a couple of repairs withing one year and 2800 miles is too much.

Not only lack of grease like speedmd says, but it looks like dirt, dust and grit has infiltrated the side cover and turned what little grease there was into a grinding paste.
This situation destroys gears very quickly, as the abrasive paste will wear the metal down fast.

When you do replace the two gears, grab a tub of lith-moly CV grease and one of those small plastic syringes. Fill the syringe up with the grease and literally inject the stuff between every tooth of the cogs.

Then fit the plastic cover and ensure it is firmly tightened by using a diagonal tightening pattern.

 

[speedmd]

Missing teeth is a sign of some sort of lock up. If it was just wear, it would be more even on most of the teeth. These gears both were replaced once, or was it just the smaller gear? You may have had packed in metal debris in the larger gear teeth causing poor engagement if it was not cleaned and inspected carefully if reused. If your only option is to replace the gears, make sure you check gear backlash and free play in the shafts/bearings or you may see the same failure in short order.

What gear ratio / bike / total weight are we dealing with here? Using just throttle makes this a motorcycle and not a electric assist bicycle. If your staying in a tall gear, it would be like driving a motorcycle in 4th or 5th gear all the time. Not going to last very long even on the flats.

.

 

[alfantastic]

Missing teeth is a sign of some sort of lock up. If it was just wear, it would be more even on most of the teeth. T

Yeah sorry, I should have elaborated a bit more. Worn, weakened teeth with some kind of lock up probably caused the teeth to fracture.
Whatever the cause, those pictures don't look good bono

I've not got a throttle fitted and use PAS only. I think that a throttle makes a rider a bit lazy in selecting the appropriate gear, whereas using the PAS makes the whole process of being in the correct gear more natural. Then again, I could be spouting a load of bollox lol :lol:

I added some more grease to the final drive at around 1300 miles, and the grease that was already in there, was still clean and uncontaminated.

The plastic cover actually has a thin gasket seal, and a thin smear of silcone grease on it before refitting, will help keep the road crud out.

 

[bono]

speedmd asked about some background information - I am 185 lbs, bike is 31 lbs; I am riding this bike actually similar to motorcycle, i.e. changing the gears as I would change on motorcycle. The difference is that I am paddling all the time. From the full stop I am using 4 gear, pedaling to 10-12 mph and then I start using throttle changing the gears gradually; if there is uphill, I am again changing the gears so the motor is not under too much load.

Maybe I do not understand how PAS works, but IMO my way of riding results in less load on the motor than PAS. I could be wrong...

 

[tomjasz]

speedmd asked about some background information - I am 185 lbs, bike is 31 lbs; I am riding this bike actually similar to motorcycle, i.e. changing the gears as I would change on motorcycle. The difference is that I am paddling all the time. From the full stop I am using 4 gear, pedaling to 10-12 mph and then I start using throttle changing the gears gradually; if there is uphill, I am again changing the gears so the motor is not under too much load.

Maybe I do not understand how PAS works, but IMO my way of riding results in less load on the motor than PAS. I could be wrong...

Bunk motor. It happens. Nothing at all wrong in the way you rode.

 

[tomjasz]

It may be that the bearings holding the shafts are worn and allowing too much clearance between the teeth now. Don't disagree that this all should have been taking care of properly the first time but as good as some vendors are they may not know any better or have tools / experience enough to see deep enough into all the component fit / wear issues early on in a products life. If it does not quite up with good thick grease, it may be time to dig deeper into this. Regardless, we all benefit from seeing and hearing all the little wear issues creep in on these and learn exactly what to do to fix them.

Missed this post..
There are still some quality issues with shafts. One design change and differences in hardening has been noted in my conversations. Not tested empirically but noted by 2 talented machinists I trust. Overall I think there are great improvements. It's still a cheap Chinese motor compared to the name brand competition. I'm expected more improvements with the new generation. Still pretty low priced for the complexity, IMO.

I still don't think there is a truly knowledgable forth coming dealer with a real handle on Bafang. After all, no one has provided any real information on any of the changes, improvements, or failures tied to real data and dates of manufacture.
Karl Electric FB has written an provided more information than all the resellers put together.

 

[speedmd]

Gear boxes are a difficult product to make well. Not surprised that a few bad ones got out. Not only is metal hardness critical, but surface finish and component rigidity are paramount. Add machining and bearing tolerances and you have a real challenge on your hands. Personally I would like to see a larger gear set to reduce tooth stress on the final stage as well as a way to take out backlash or easily replace gears when they get sloppy.

 

[votecdesign]

I changed transistor (P75nf 758, has burned) now I have a problem with error 21 (speed sensor)
I remove silicone and maybe a SMD part (it looks like)

Have somebody a picture of silicone free plate?

 

[darth_elevator]

For the record, I used the following grease:
@ nylon & steel helical bearings - sil- glyde. http://www.amazon.com/SILGLYDE-LUBE...UTF8&qid=1397698406&sr=8-1&keywords=sil+glyde
@ crank shaft roller & ball bearings - Buzzy's Slick Honey http://www.amazon.com/Buzzys-Slick-...8&qid=1397698491&sr=8-2&keywords=honey+grease
@ final straight cut gears - standard dark gray Moly grease

My bbs02 is still running strong at 2000+ km, but I think it's time to lubricate it, as a quiet growl has slowly started developing over the last 200 miles or so. It's not super loud, so I've been inclined to just leave it, but I believe it is a bit louder now than it was when I first heard it. So I thought I'd go ahead and order the grease that Teslanv used.

I've got the Silglyde and Buzzy's in my cart, but I'm not exactly sure what Moly grease I should use. (I don't even know what Moly grease is, let alone what "standard" Moly grease is, or whether it's critical that it's dark gray.)

Does this look like a good moly grease for the BBSO2?

http://www.amazon.com/Red-Line-80401-Synthetic-Grease/dp/B0053O9FQS/ref=sr_1_1?ie=UTF8&qid=1442866289&sr=8-1&keywords=moly+cv+grease

Any other moly grease from amazon that anyone would recommend over this? Or is moly grease something I can pick up at an Autozone type store? Thanks in advance, and, as always, I apologize for having virtually zero technical knowledge in this area.

Also, am I correct in understanding that this Moly grease goes on the first gear you come across when opening up the gear housing? If so, should I consider greasing this first gear only and testing to see if it eliminates the growl, or (in a best practices sense) should I lubricate all the gears while I've got the housing opened up? Any advice would be greatly appreciated.

Thanks!

 

[speedmd]

Moly grease is available in any of the major auto parts stores. It is used in CV joints commonly. They will understand if you ask for that. I would not waste the money on it.

I use a good medium thickness high temp extreme pressure synthetic water proof grease on everything I own. Makes it simple. 15 plus years on a wide range of equipment and has not failed me yet. Does not dry out anywhere near as quickly as the standard cv joint stuff does. Not tried the red stuff.

 

[jk1]

Yes, those are missing teeth. Do you have any idea what can cause that kind of damage after less than 1000 miles? I accept that things break ) But either I have too much expectations from Bafang motor, or a couple of repairs withing one year and 2800 miles is too much.

Those gears are shot and need a complete replacement. That's the problem with this complicated gear reduction design it is hard and costly to repair and you have pretty much reached the end of the whole motor and gearbox at 2800 miles. And since its all in one piece you pretty much need a whole new motor gearbox and controller. If the gearbox was detachable like the cyclone kits you could just replace the gearbox or even better just the planet gears. On those you can do like 5000km and easily change a set of planet gears for $30 USD and do another 5000km. With the BBS02 you need to scrap the lot and spend $500 usd to start from scratch..... this could be very costly if you plan do a lot of Kms per year , some people do 10,000 km per year ....

 

[speedmd]

If the cases are made correctly (pockets for shaft bearings in correct positions) and bearing pockets are not bagged out, there is no reason you just can not replace the gears / shaft assemblies / bearings and go on with it. It is a bad unit most likely and early in the product life cycle. Some bugs still need working out. Some omissions and some certainly commissioned. As for comparing this to a cyclone with a crank /jack setup, seriously? You have a whole other set of failure points needing regular attention never mind the sound of it that you can do nothing about. Nothing comes close to the simplicity and long term reliability of a direct drive hub which anyone needing a bullet proof commuter setup needs to compare as a best long term high miler option.

 

[darth_elevator]

Moly grease ... I would not waste the money on it.
...
I use a good medium thickness high temp extreme pressure synthetic water proof grease...

Thank you, that's good to know. How about Superlube? I already have some of that on hand.

 

[tomjasz]

Yes, those are missing teeth. Do you have any idea what can cause that kind of damage after less than 1000 miles? I accept that things break ) But either I have too much expectations from Bafang motor, or a couple of repairs withing one year and 2800 miles is too much.

Those gears are shot and need a complete replacement. That's the problem with this complicated gear reduction design it is hard and costly to repair and you have pretty much reached the end of the whole motor and gearbox at 2800 miles. And since its all in one piece you pretty much need a whole new motor gearbox and controller. If the gearbox was detachable like the cyclone kits you could just replace the gearbox or even better just the planet gears. On those you can do like 5000km and easily change a set of planet gears for $30 USD and do another 5000km. With the BBS02 you need to scrap the lot and spend $500 usd to start from scratch..... this could be very costly if you plan do a lot of Kms per year , some people do 10,000 km per year ....

Bono got the run around but hopefully it's being attended to, at last. There are units out there with much higher mileage. If I were reselling BBS0x I think I'd open them up and check out the lube, especially if it were to be rode hard. One of my BBS01's needed lube, the second was fine.

 

[speedmd]

The Super lube looks like a good product, but I have only used it a few times. I remember it being a bit liquid and did not stay put too well. PTFE is typically not that great in extreme pressure situations, but worth a try rather than run it dry.

I like the look of the red line stuff but have no experience with it. https://www.pegasusautoracing.com/productselection.asp?Product=1694&gclid=CLWzzsiwi8gCFVcSHwod3sEKgQ

 

[darth_elevator]

Thanks much!

 

[jk1]

by speedmd » Tue Sep 22, 2015 11:34 am

If the cases are made correctly (pockets for shaft bearings in correct positions) and bearing pockets are not bagged out, there is no reason you just can not replace the gears / shaft assemblies / bearings and go on with it. It is a bad unit most likely and early in the product life cycle. Some bugs still need working out. Some omissions and some certainly commissioned. As for comparing this to a cyclone with a crank /jack setup, seriously?

I have only seen some limited plastic gears available as spare parts, this one above has the main large steel gears damaged. So even if you could source all the gears, bearings and shafts,its a machinist job to be able to assemble them and put it back together and get the alignment and clearances right again. It's not something that anyone can DIY, and then what would the cost ? hence why others suggested also starting from scratch is probably cheaper. but its still 500 usd...

Like I mentioned earlier having a separate gearbox like the cyclone would solve this, in that gearbox anyone can unscrew it and replace it completely for $100 USD or just the planet gears for $30 . The other wearing parts are external to it I.e bike chain and freewheels that anyone can cheaply replace from any bike shop parts.

You can't compare the two in terms of how simple and cheap they are to do a lot of kms on or refurbish, I have heard of some people doing 20,000 km who regularly oil it on the original cyclone gearbox they are high quality made by headline in Taiwan. Grease is not a good lubricant for high speed and long life like oil.. have you ever seen a car gearbox or differential with grease in it ? For the BBS02 isn't that like all Chinese made things ? they are on purpose designed to be cheap to buy and have a short life span and hard to repair, so you then become an continuing income source for them as most people are too short-sighted to only look at the cheap purchase price and not the ongoing costs..

 

[speedmd]

All these parts are available for the BBS, and easily replaced. We need to get the full story as to what really went down on the one with missing teeth. This is not what most folks using them are experiencing. As I said before, the two systems are completely different classes of refinement and not comparable at all. Certain that some bbs systems got through with soft gears, but also certain that this will be corrected in short order as their domestic market (which is huge) is very concerned with life cycles and cost of ownership.