Bafang crank engagement broken

[Mark Lester]

Just persevere

The dust cap is sacrificial - it's just a rubber coated steel washer. Once the rubber is completely removed, the remaining steel part can be removed with a magnet.

Following a similar repair, I ran without a dust seal whilst waiting for gbk to send a spare seal

ok, so its not a cap then, it looks like a screw in cap but you think its just a washer they've started putting in. i am deluding myself trying to squeeze a stanley under what i am perceiving to be a cap that screws in and comes up over the shaft. i dont have a magnet but will go get this affy.

 

[Mark Lester]

i got nice long pliers (they didnt have the bent ones but these should work) from wilko. i didn't know they did nice cheap bike bits, so thanks guys for that. I also got a nice magnet on a telescopic ariel thing, but its too big to fit between the spindle and the outer shaft to pluck this washer up, but there is still a bit of rubber stuck to it which i can get to with the pliers and nothing is moving when i tug on that. so its an afternoon watching human 500W generators doing daft things on bikes and i will go see my car fixing guys tomorrow and report back.

 

[Mark Lester]

Oh fiddlesticks. Just been down to my helpful car fixing guys. It wont budge. Short of just getting another I am a wee bit stuck now. There was one vid where he attacked it with a hammer to knock the spindle out, which is not the one I posted but I will and find it again. I will need to buy a few tools anyway before doing this, I have no vice or appropriate hammer. I wont start doing this before showing you what I am about to try.

 

[Mark Lester]

I cannot find the the one with the vice and the hammer, you will probably be relived to hear, i certainly am. I rang the lovely guys at BGA Reworking in London where i got it and the batt from, and he said send it in and they will try and work out what's going on. They have direct contact with the factory so we'll get to the bottom of this. I will do my duty and make sure I conclude this thread when we've sorted it.

 

[Deleted member 4366]

He only tapped it out, and that was after removing the ring nut. You can smash yours with a sledge hammer, but it won't come off until you get the one or two ring nuts off.

Clean it with petrol and then take a clear photo of what's in there so that we can see what the problem is.

 

[Mark Lester]

He only tapped it out, and that was after removing the ring nut. You can smash yours with a sledge hammer, but it won't come off until you get the one or two ring nuts off.

Clean it with petrol and then take a clear photo of what's in there so that we can see what the problem is.

I took it to a car repair place and told him it was a washer that should just lift off. He begged to differ. This is as far as i have got. It had rubber on it with 6 indents. I will wrap it up and send it to BGA and see what we can do
https://www.dropbox.com/s/jrr9qm31et341pi/DSCF0061.JPG?dl=0

 

[Mark Lester]

that photograph suggests there is a ring that fits inside and over the top of the outer shaft that secures the washer. how we get that off i dont know, i cant get a fine blade under it.

 

[Nealh]

The last time I removed the drive shaft was over 2 years ago,it really was an easy job with the unit still all connected to the bike.
I don't recall having an end washer as your pic but it should just lift of/come away with a magnet.

Lock nut assembly on non drive side.


Drive shaft assembly


PAS function /hall sensor, behind final drive.

 

[Deleted member 4366]

that photograph suggests there is a ring that fits inside and over the top of the outer shaft that secures the washer. how we get that off i dont know, i cant get a fine blade under it.

It's still covered in grease and crud, so we can't see what it is. Why don't you clean it so that we can see what it is?

In the meantime, we can only go by your description. lets assume that it's a normal shaft seal:

The steel under the rubber is thin. they can normally be prised out by tapping a small screwdriver or spike through the metal with a hammer, then using it to lever the seal out.

 

[rich_r]

I sometimes end up drilling a small hole and screwing a self tapping screw into those sort of seals if they're stuck. Then you can get pliers under the head of the screw to pull with more force.

 

[Mark Lester]

its not grease, its the rubber i have been trying to scrape and pull off.it was quite a thin amount, not like the thicker rubber ones. Ms Alice at green bike kit is talking to me cos she doesnt know if I have ordered the right lock nut tool ( I know I dont really need that) I sent her the pic.
I will try and get the rest of this rubber off.
Attacking it with a drill is scary, but she wont move.

 

[Deleted member 4366]

The rubber is only a coating. Don't waste your time with that. You need to get a hole in the steel so that you can prise it out. Underneath is the dogged nut, do you can't do any harm by drilling it.

Get a jamjar. Put some petrol in it. Stick the motor shaft in and shake it about. It'll come out without all that grease and sand on it so that we can see if there's a lip on that seal to confirm that it is indeed a seal.

 

[Mark Lester]

The rubber is only a coating. Don't waste your time with that. You need to get a hole in the steel so that you can prise it out. Underneath is the dogged nut, do you can't do any harm by drilling it.

Get a jamjar. Put some petrol in it. Stick the motor shaft in and shake it about. It'll come out without all that grease and sand on it so that we can see if there's a lip on that seal to confirm that it is indeed a seal.

ok, i used a bit of white spirit and its a bit cleaner
https://www.dropbox.com/s/c2qrolelows3tkr/DSCF0064.JPG?dl=0
i think there some inner sleeve in it, that both fits over the top and also has a rim to keep the washer from moving, you can see this rim at the bottom of latest pic. i did point the drill at it. i need a smaller drill bit but if this is right it wont matter, we've got to get this washer securing inner sleeve thing off. i'll try the jam jar trick and white spirit for an hour and see if i can at least get you a nice shiney picture.

 

[Deleted member 4366]

So, is that a rubber lip in the middle or the start of the thread?

 

[Fordulike]

See what you mean now Mark. Guess Bafang did a waterproofing revision somewhere along the line.

 

[Mark Lester]

So, is that a rubber lip in the middle or the start of the thread?

its part of the spindle, when i turn it that bit moves, its below the washer and will have had some rubber on it as part of this new regime and form a seal with the thin layer of rubber on the immovable washer system.

See what you mean now Mark. Guess Bafang did a waterproofing revision somewhere along the line.

the serial number is 1611266532 and its a BBS02B 48V500W.
so does that mean made november last year ?

I cleaned it some more, here's as good as i can get it
https://www.dropbox.com/s/t4xsaavfpoggfa5/DSCF0072.JPG?dl=0

I am hoping Ms Alice can help out, I've already ordered the clutch thing.

 

[Mark Lester]

its not below the washer its the same level as, but anyway that ring around the spindle/axle is part of the spindle.

 

[Mark Lester]

https://electricbike-blog.com/2016/07/12/bafang-completely-redesigns-the-bbs02-and-tells-no-one/

v2 of the BBS02 has a new rubber washer at the end of the axle that I have yet to figure out how to get past without completely destroying it.

so we are officially screwed guys. I have a version B and nobody knows how to get in.

 

[Deleted member 4366]

That's a seal just like I showed you in the photo above. They're easy to get out, like we told you, but you don't seem to listen. drill or punch a hole in it and hook it out. Simples!

You can get a replacement from your local bearing supplier for about £1.

 

[Woosh]

You can get a replacement from your local bearing supplier for about £1.

you do have a part number or dimensions of the seal?