Cheeb issues :-(

demondazza

New Member
Aug 30, 2021
16
16
Oxfordshire
That's awesome advice, thanks. Do you know where they can be purchased from? I had imagined that it might be a nightmare trying to source them from Bafang. I'm not really clued up on these things so no idea if they are standard parts or bespoke from Bafang.
Cheers!
 

Sheff73

Active member
Feb 13, 2021
98
82
UK
The one-way bearings will not be 'Bafang specific'. You can get the part numbers from the side of each bearing and then just Google search for a supplier. Very easy and cheap to source.
It looks like there maybe some bearing number differences within the M600 motor during its manufacture, so best look inside yours and see exactly what you have.

The one-way bearings are easy to spot, as they will have an arrow on the side (see attached). Make sure you know the orientation of said bearings before removing!

1637675760585.png


Here's a few more links that might be useful.


 

demondazza

New Member
Aug 30, 2021
16
16
Oxfordshire
The one-way bearings will not be 'Bafang specific'. You can get the part numbers from the side of each bearing and then just Google search for a supplier. Very easy and cheap to source.
It looks like there maybe some bearing number differences within the M600 motor during its manufacture, so best look inside yours and see exactly what you have.

The one-way bearings are easy to spot, as they will have an arrow on the side (see attached). Make sure you know the orientation of said bearings before removing!

View attachment 76606

Here's a few more links that might be useful.


That's great advice - many thanks. I will strip down and take a look. I'll report back once I've replaced the bearings just in case anyone else has the same issue. Cheers and thanks again
 

captainhightop

Active member
Feb 26, 2021
136
143
UK
For sure, this is water ingress either on the switch itself or more likely, as it was in my case the battery dock. The symptoms were the same, ticking sound from battery (even when display off). If I could turn on the display, battery percentage going from 0% to 90% and inbetween at more or less the frequency of the ticking. Power was mostly < 20W if I could get anything out of it, but occasionaly would shoot up to normal levels.

All attempts to stop this were:
- potting the back of the dock
- drilling holes in the bottom of the dock

Both of these, only reduced the likelyhood of his happening. Taking the battery apart and linking the switch wire to be always on to the BMS has so far been successful in wet conditions and during cleaning. This does mean that the battery is kinda always on, but all my other DIY bikes were like this anyway and you still have to turn on the bike via the display anyway.

The clicking I think is some sort of relay on the BMS that is flicking on and off due to the on/off switch making and breaking due to the water bridging the contacts (pogo pins or back of them at least). Most BMS's I've used on my self build batteries came with this wire permanently linked so I wasn't too worried about changing Dengfu's battery to behave this way.

I've also added a fabric cover the length of the battery cover to stop the mud blocking up the sliding catch as that was a big pain too, and it has the side effect of providing a bit of extra waterproofness.

Still nervous about it obviously, but no more than the BBSHD and their seemingly fragile controller (at least in British winters). If this doesn't fix it, I'll be retrofitting an external controller somehow unless a cheap source of replacement controllers becomes available (used a BAC800 with eggrider on BBSHD for a while, and a cycle analyst for more fine grained PAS control with their phaserunner kit). The grin baserunner (Baserunner - Grin Products - Product Info) could be a candidate to fit inside the frame with a custom battery and a bit of work I think.

Still I'd rather keep it stock than have to work all that stuff out so fingers crossed I make it through the winter without any more issues.

Hi all,

I recently bought a secondhand cheeb with an M600 motor. Everything was great, took it for my first ride on Sunday and had a total blast, though the weight is going to take some getting used to. Got home, bike covered in mud and battery nearly flat.

So washed the bike (with a gentle hosepipe), charged the battery and took the opportunity to move the display a little, which necessitated unplugging the two cables that go into the back of the display.

Once the battery was charged, turned the bike on and I'm greeted with 3 odd things:

1) A ticking noise from (I think) the motor area.
2) The display showing spurious battery readings. First 60%, then 0%, then 10%, then powering off.
3) The bike pretty much not working.

If I try to ride the bike, then when the motor kicks in it feels kind of 'grungy'.

I've taken the battery out and checked the contacts are dry, I've also pushed the connectors into the display as hard as I can, as I've read that often this is the cause of such issues.

Kind of panicking here!

Any ideas?
 

demondazza

New Member
Aug 30, 2021
16
16
Oxfordshire
The one-way bearings will not be 'Bafang specific'. You can get the part numbers from the side of each bearing and then just Google search for a supplier. Very easy and cheap to source.
It looks like there maybe some bearing number differences within the M600 motor during its manufacture, so best look inside yours and see exactly what you have.

The one-way bearings are easy to spot, as they will have an arrow on the side (see attached). Make sure you know the orientation of said bearings before removing!

View attachment 76606

Here's a few more links that might be useful.



Hi,

So I've stripped down the M600 motor and removed the clutch bearings - tricky but got there! The smaller clutch bearing is marked HFL1426 and this has now been replaced. Unfortunately, the larger clutch bearing has no writing/model number on it and appears to be a very strange size. Initially, I thought it was a HF3520 but it turned up and is smaller than the bearing that was removed. On closer inspection, the larger clutch bearing on the Bafang M600 has a measurement of approx 36 x 43 x 21 mm. Having looked for this bearing online, there appears to be no one who sells anything of this size. The only reference I can find is a KOYO bearing RFU364322A but this appears to have a 22.4 mm depth which is too big.

Does anyone know where these parts might be available? Until I can find one, the Cheeb isn't going anywhere as the larger bearing was damaged on removal. Gutted!

picture1.jpeg
 

Sheff73

Active member
Feb 13, 2021
98
82
UK
Nightmare!

I've had a good route around the tinterweb and like you come up with nothing, other than the HF3520 bearing that's even close to your measurements. Even imperial equivalents are no where near in size...

Have you measured the bearing dimensions with a rule or something more accurate such as a digital caliper?
Have you actually tried fitting the HF3520 in place?

Bafang will not be making their own bearings, as it makes no economical sense. Might be worth reaching out to them via Ben Rides (Dengfu rep) to ask what the bearing actually is?

M.
 
Last edited:

demondazza

New Member
Aug 30, 2021
16
16
Oxfordshire
Nightmare!

I've had a good route around the tinterweb and like you come up with nothing, other than the HF3520 bearing that's even close to your measurements. Even imperial equivalents are no where near in size...

Have you measured the bearing dimensions with a rule or something more accurate such as a digital caliper?
Have you actually tried fitting the HF3520 in place?

Bafang will not be making their own bearings, as it makes no economical sense. Might be worth reaching out to them via Ben Rides (Bafang rep) to ask what the bearing actually is?

M.
So I borrowed a decent digital gauge from a friend and measured the bearings properly. The 'exact' measurements are 42.99mm diameter, 35.99mm internal diameter and 21.8mm depth. It looks like the KOYO is almost exact, if not slightly deeper by .4mm which I think could work okay. It's just finding one... I'll reach out as you recommended. Thanks for your help. I fear I won't be riding the bike for a while :(

The HF3520 literally just falls very loosely inside the bearing recess and the inner gear doesn't fit inside either so it's the wrong size from every angle. Shame - I thought I had it nailed.
 

Sheff73

Active member
Feb 13, 2021
98
82
UK
So I borrowed a decent digital gauge from a friend and measured the bearings properly. The 'exact' measurements are 42.99mm diameter, 35.99mm internal diameter and 21.8mm depth. It looks like the KOYO is almost exact, if not slightly deeper by .4mm which I think could work okay. It's just finding one... I'll reach out as you recommended. Thanks for your help. I fear I won't be riding the bike for a while :(

The HF3520 literally just falls very loosely inside the bearing recess and the inner gear doesn't fit inside either so it's the wrong size from every angle. Shame - I thought I had it nailed.

Ah that sucks. At least you have the exact measurements and hopefully can find a KOYO bearing from somewhere. I'll have a search as well.
 

demondazza

New Member
Aug 30, 2021
16
16
Oxfordshire
Ah that sucks. At least you have the exact measurements and hopefully can find a KOYO bearing from somewhere. I'll have a search as well.
Thanks man. I’ve asked the question to melody so hopefully she can reach out to Bafang and get a definitive answer on what the part is 👍
 

Ausmtb

New Member
Dec 31, 2021
5
8
Australia
How did you go finding that bearing Dazza?
I have had the same problem you had been experiencing with slipping of the crank on initial pressure when cranking.
Here are my thoughts on the issue:-
The larger one way bearing seems to be the bearing causing the slippage.
I have taken my motor apart and had a good look at the bearing without taking the bearing out of the assembly, not sure how you would take it out without damaging it, seems that you would have to put some type of expanding tool inside the one way bearing and slide hammer it out? Is that how you removed yours?
The bearing in my motor did seem to me to be in good order, tight tolerance and working in one direction. It also was very well greased.
This sprag bearing is a very interesting bit of engineering. If your unfamiliar to how it works have a look at this video.



For this bearing to work without slipping the sprag bearing surfaces must grip the inner bearing bush, both of which a hardened smooth metal surfaces.
When I pulled my bearing apart the inner bush bearing was well coated in a grease as you would probably expect, however its my belief too much lubricant between these two surfaces can cause initial slippage of the sprags onto the inner bush hardened surface.
I carefully wiped out the sprag bearings removing some of the grease but not all of it and fully cleaned the bush with contact cleaner.
I have now done 150km since the rebuild without any slippage so it has seemed to work.
I think the key is to have just enough grease in the bearing for the sprags to work correctly but not so much that the sprags have difficulty gripping onto the bush so you don’t get that initial slippage.
It got me thinking why the bearing worked from new and started slippage after about 1 month from new and progressively got worse.
Maybe with heating up of the grease within the motor housing during extended use allowed excessive grease to leak into the sprag bearing joint and over lubricate this area?
I think if this becomes an ongoing issue, I will replace the internal grease with a higher melting point grease with the aim of keeping the grease where its needed and away from where its not needed, but at the moment all seems good.
 

markvanhaze77

Member
Jun 14, 2021
37
15
GB
How did you go finding that bearing Dazza?
I have had the same problem you had been experiencing with slipping of the crank on initial pressure when cranking.
Here are my thoughts on the issue:-
The larger one way bearing seems to be the bearing causing the slippage.
I have taken my motor apart and had a good look at the bearing without taking the bearing out of the assembly, not sure how you would take it out without damaging it, seems that you would have to put some type of expanding tool inside the one way bearing and slide hammer it out? Is that how you removed yours?
The bearing in my motor did seem to me to be in good order, tight tolerance and working in one direction. It also was very well greased.
This sprag bearing is a very interesting bit of engineering. If your unfamiliar to how it works have a look at this video.



For this bearing to work without slipping the sprag bearing surfaces must grip the inner bearing bush, both of which a hardened smooth metal surfaces.
When I pulled my bearing apart the inner bush bearing was well coated in a grease as you would probably expect, however its my belief too much lubricant between these two surfaces can cause initial slippage of the sprags onto the inner bush hardened surface.
I carefully wiped out the sprag bearings removing some of the grease but not all of it and fully cleaned the bush with contact cleaner.
I have now done 150km since the rebuild without any slippage so it has seemed to work.
I think the key is to have just enough grease in the bearing for the sprags to work correctly but not so much that the sprags have difficulty gripping onto the bush so you don’t get that initial slippage.
It got me thinking why the bearing worked from new and started slippage after about 1 month from new and progressively got worse.
Maybe with heating up of the grease within the motor housing during extended use allowed excessive grease to leak into the sprag bearing joint and over lubricate this area?
I think if this becomes an ongoing issue, I will replace the internal grease with a higher melting point grease with the aim of keeping the grease where its needed and away from where its not needed, but at the moment all seems good.
That's very useful info, thank you. I'm in the same boat with my m600 slipping so I will look into cleaning that out and greas it just enough.
Did you have any further slippage since your fix?
 

Ausmtb

New Member
Dec 31, 2021
5
8
Australia
That's very useful info, thank you. I'm in the same boat with my m600 slipping so I will look into cleaning that out and greas it just enough.
Did you have any further slippage since your fix?
It’s been all good since I cleaned out alot of the grease from the one way bearing. Haven’t had any reoccurring issues so far.
 

Dancarbon

Member
Jul 16, 2021
7
1
Twickenham
Hi there,

Had the same problems on my Cheeb.
Started at 200km just after the build, contacted Dengfu without an answer, so investigated myself and found out the on/off button is not waterproof, I bypassed the switch which solved the problem until last week :confused:

After doing some muddy terrain, cleaned the bike to hear the ticking noise again.o_O
Checked all the wiring to the display and motor and opened the battery connector (removed the white smudge) to find out it was moisturized inside! Seems Dengfu needs improvement on the electrics.

Hope this info helps for future owners.

View attachment 74001
When you say you removed the white smudge do you mean the white rubber thing that is over the connector just below the battery isolation switch?
 

captainhightop

Active member
Feb 26, 2021
136
143
UK
When you say you removed the white smudge do you mean the white rubber thing that is over the connector just below the battery isolation switch?
To be really sure, you need to disable the on/off function by linking the wire in the battery internally. No realistic way to waterproof the pogo pins so just bypass in the battery, and water getting in the switch itself is only half the problem.

If you just detach the switch (unless I'm reading you wrong here!), when the dock gets wet it will continually short the switch circuit in the battery causing the output to go on/off randomly.

Just need to be sure you don't put the battery anywhere where you can short the outputs if you do the bypass otherwise you might get a big spark!
 

markvanhaze77

Member
Jun 14, 2021
37
15
GB
It’s been all good since I cleaned out alot of the grease from the one way bearing. Haven’t had any reoccurring issues so far.
I did 100km now with the bearing cleaned out but not completely driy and it has absolutely fixed the issue. I still have very few slips, usually after a good shake down in roguh terrain while not pedalling, but ill just clean that bearing out one more time as im guessing some of the fine lube came back into the teeth of that bearing.
 

ficorama

Active member
Oct 9, 2021
308
285
Croatia
as far as i was able to find the problem is with the water in this part. the battery connectors are molded in a plastic housing. which is inserted into the aluminum battery holder and on the other hand is closed with silicone. that's where the water comes in, and it's short-circuited. when i took this part off the bike the water was coming out.

20220120_201827.jpg
 

RoyRoy

Member
Sep 9, 2021
29
5
Australia
Hi there,

Had the same problems on my Cheeb.
Started at 200km just after the build, contacted Dengfu without an answer, so investigated myself and found out the on/off button is not waterproof, I bypassed the switch which solved the problem until last week :confused:

After doing some muddy terrain, cleaned the bike to hear the ticking noise again.o_O
Checked all the wiring to the display and motor and opened the battery connector (removed the white smudge) to find out it was moisturized inside! Seems Dengfu needs improvement on the electrics.

Hope this info helps for future owners.

View attachment 74001

I like your frame paint job!
Sorry if this is touched on down below, has anyone had any trouble with the battery itself taking water inside?
 

vudu

Member
Dec 13, 2021
10
3
Sydney AU
Sorry if this is touched on down below, has anyone had any trouble with the battery itself taking water inside?

Haven't opened the battery but have had moisture in the battery cavity. Once from a big puddle, once from washing the bike (low pressure garden hose). A fair bit of crud accumulates on the battery cover.

The first instance, the big puddle, caused to motor to stop working a few km's from home and down 80 m's of bush tracks. Pushed the fat pig home in disgust.

Both times I removed the battery and directed a fan to the lower battery mount / connection. Came good after a few hours of drying.

Have since coated electrical terminals with dielectric grease and fashioned a some closed cell foam to minimise water ingress. Recent change so no proper testing yet. Interested to hear if anyone has a practical, permanent fix. Quite an obvious weakness after 150 km's of ownership. Also had to disassemble the battery cover lock to clean and grease as was almost inoperable with captured grit.

DSC_0698.JPG


DSC_0692.JPG
 

Chickon1

Member
Nov 8, 2021
28
11
FL
I have the same issue with the bearing.. It started with a back pedal then forward was the only time it would happen.. now it's pretty much jacked if you stop pedaling at all. I only have about 100 miles on it.. I will see if cleaning it works sense I added more grease which made it way worse than it was.
 
Last edited:

Chickon1

Member
Nov 8, 2021
28
11
FL
Well, I took it apart again and cleaned all the new grease I added which made it way worse in after reading this.. works fine now. Basically once I cleaned it with brake cleaner, I could start to feel the little needle bearing move in an out (on the big one).. didn't put any grease on the inside big needle bearing or the outside of the clutch (piece that the big bearing slides over). The small needle bearing that the axle sits on didn't seem to be one way so I greased that and of course all the other contact points.

On demondazza pic that has the large gear and bearing apart above.. no grease on the inside of the left and the outside of the right. That is basically acting like a fiction clutch.
 

uef2

New Member
Nov 22, 2021
18
4
Germany
Hello to the forum,

is there now a better solution for motor protection? I have already installed the third rock guard. Those things break out just from the vibration!

IMG_20220306_151329~2.jpg


IMG_20220306_151616~2.jpg
 

Yendor

New Member
Mar 18, 2022
3
0
Sydney Australia
Hi all,

I recently bought a secondhand cheeb with an M600 motor. Everything was great, took it for my first ride on Sunday and had a total blast, though the weight is going to take some getting used to. Got home, bike covered in mud and battery nearly flat.

So washed the bike (with a gentle hosepipe), charged the battery and took the opportunity to move the display a little, which necessitated unplugging the two cables that go into the back of the display.

Once the battery was charged, turned the bike on and I'm greeted with 3 odd things:

1) A ticking noise from (I think) the motor area.
2) The display showing spurious battery readings. First 60%, then 0%, then 10%, then powering off.
3) The bike pretty much not working.

If I try to ride the bike, then when the motor kicks in it feels kind of 'grungy'.

I've taken the battery out and checked the contacts are dry, I've also pushed the connectors into the display as hard as I can, as I've read that often this is the cause of such issues.

Kind of panicking here!

Any ideas?
Hi There new to forum,
I to built a cheeb but not working after getting caught out in the rain.
Had above problems, but after drying everything out and bike pulled apart 3 times now and still no luck.
Display lights up after pressing on /off switch on side of bike without touching controller.
I also get a error 36.
I am stumped.
 

Hagbard

Active member
Aug 25, 2021
103
54
York
Hi There new to forum,
I to built a cheeb but not working after getting caught out in the rain.
Had above problems, but after drying everything out and bike pulled apart 3 times now and still no luck.
Display lights up after pressing on /off switch on side of bike without touching controller.
I also get a error 36.
I am stumped.

According to a manual that I found online here error 36 suggests a problem with the 'button' circuit:

36 Detection circuit for button is fault

Not sure whether this is the power button on the bike frame, or the buttons connected to the display. I think I'd try to eliminate the latter first by ensuring that the connector between the display and the buttons (i.e. the ones you use to control the assistance level) is dry and correctly inserted. Those connectors can be a bit of a pig, and always need pushing in further than you think.

Failing that, if it relates to the power button on your frame then there are definitely instructions on here relating to running the bike without it. It is seen by many as an unnecessary point of failure, and seem to be the thing that's most affected by water ingress. Make sure you point a hairdryer inside the top part of the frame where the button is to ensure this area is well dried out - doing this was the thing that fixed my bike. I even have a 'special' hairdryer now that I use exclusively to dry this area, and the are by the battery contacts, whenever I wash my bike.

Hope this helps, I know well the stress caused by these things breaking!
 

Yendor

New Member
Mar 18, 2022
3
0
Sydney Australia
According to a manual that I found online here error 36 suggests a problem with the 'button' circuit:

36 Detection circuit for button is fault

Not sure whether this is the power button on the bike frame, or the buttons connected to the display. I think I'd try to eliminate the latter first by ensuring that the connector between the display and the buttons (i.e. the ones you use to control the assistance level) is dry and correctly inserted. Those connectors can be a bit of a pig, and always need pushing in further than you think.

Failing that, if it relates to the power button on your frame then there are definitely instructions on here relating to running the bike without it. It is seen by many as an unnecessary point of failure, and seem to be the thing that's most affected by water ingress. Make sure you point a hairdryer inside the top part of the frame where the button is to ensure this area is well dried out - doing this was the thing that fixed my bike. I even have a 'special' hairdryer now that I use exclusively to dry this area, and the are by the battery contacts, whenever I wash my bike.

Hope this helps, I know well the stress caused by these things breaking!
Thanks Hagbard,
In desperation I ordered new display and assistance level buttons.
I know it’s not the one on the frame as I put another switch on.
I never did find anything about error 36 that’s why I posted here.
Thanks for replying and will let you know how I go.
Cheers Rod
 

captainhightop

Active member
Feb 26, 2021
136
143
UK
It's very difficult to expel all the water from the pogo pins on the battery dock that the switch connects to (which is why I advocate removing the switch and modifying the battery).

Also the controller and/or HMI don't have any way of telling the state of that switch on the side of the bike as it's an input into the battery. (Other than the absence or presence of power). So the button error code isn't about that button exactly, it's about a button on your HMI.

When my bike was were drenched I didn't get error 36 but it did come on without even pressing any buttons as soon as the button on the side was pressed and sometimes without having the button pressed at all duentonthe water shorting out the pogo pins.

There was a characteristic clicking sound coming from the battery due to the battery switch circuit flicking on and off too when this was happening.

Water can also get into the motor and mess up the canbus and other signals, so the error you get isn't necessarily down to the HMI either.

Even after doing the battery mod, I messed up and turned the bike upside down causing a small amount of water in the motor itself to go where it shouldn't have done (after a wet ride). I was luckily able to rescue my controller with careful disassembly and cleaning, but there was a fair amount of corrosion and bare copper showing that needed covering up on the drive control board and the board with the connections to the outside world.

eBikes and rain are always a gamble if you've not prepared for it, and even then you can still get screwed. Its not just Bafang though, all major suppliers have these kind of issues in one way or another, it's improving, but all adds to cost and in the meantime Bafang lag behind in some of these issues. They do conformally coat some of the electronics, but some of the through hole connectors have bare conductor and that's where mine had corrosion which I cleaned off with iso.

I'm thinking it needs some sort of place for water to exit, or other such strategy.
 

Yendor

New Member
Mar 18, 2022
3
0
Sydney Australia
Thanks for reply,
There was clicking sound but not anymore.
Error 36 appeared after clicking had stopped after drying everything.
Now waiting for new assist button and display and will go from there.
It rained so hard that it was like putting the bike under the shower.🤣
 

captainhightop

Active member
Feb 26, 2021
136
143
UK
Thanks for reply,
There was clicking sound but not anymore.
Error 36 appeared after clicking had stopped after drying everything.
Now waiting for new assist button and display and will go from there.
It rained so hard that it was like putting the bike under the shower.🤣
I know the feeling :cry:, I've drilled a few holes in the metal part of the dock hopefully to drain water away also and covered the top and bottom of the battery door on the frame with an old innertube to stop too much spray getting in, but it always gets in some way or other! Also covered the oval bashguard holes with tape to stop spray hitting the motor and I'm working on a better bashguard design to reduce spray further.

It feels like never ends sometimes, especially in UK winters!

I had worse problems on other motors though (BBSHD and Bosch). BBHSD was solved by an external phaserunner controller and the bosch fixed under warranty and then sold it.
 

Hagbard

Active member
Aug 25, 2021
103
54
York
@captainhightop Kind of relevant to our other discussion about HMI buttons (I feel like I need a word for this, but "controller" is already taken). If we think that this is just 3 switches then in @Yendor 's case above it's almost certainly a fault with the display itself, right?

@Yendor assuming you're running a DPC241 HMI if you unplug the remote part (hah! I think "remote" is the word I'm looking for!) do you still get an error on the HMI when you turn the bike on with the frame switch?

I appreciate it isn't terribly helpful if the error goes away, as at this point you have no means of actually switching the bike on, but it does help our overall understanding of things.

EDIT: I guess if this does lead us to the conclusion that the HMI is somewhat toasted, then we could always try the bag of rice trick to dry it out. Or stick it in the oven for a bit....
 

Dean R

Member
Jul 9, 2021
17
4
Chesterfield
I've seen the same problem rarely on my TSDZ2 motors, always the one way bearings and always they work fine when turning by hand. I've even taken a couple apart trying to see what the problem is but they always look perfect. The ones we replaced were always only a problem in colder temps and we put it down to incorrect grease in the bearing. But if the motor was working you would expect it to warm pretty quickly so we couldn't really isolate it down to temperature.

It will be only one of the bearings, the one that isolates the crank and it will be clear to see which one. Good quality replacements are not so expensive.
Hi what would you suggest to use as lubricant on the clutch bearing ?
As I can’t find any info online by bearing manufacturer on what lubricant should be used.
 

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