Bafang? 750w? motor bearing replacement

[s-petersen]

Bafang? 750w? motor?
I am repairing an e-bike for a friend, and I need to replace the wheel bearing on the cassette side. Do I need to remove the cassette? I don't see a brand name on the motor, or the size, as a mater of fact the bike was repainted, and I can't find that either. This is the closest bike I can find, but I could swear it has rear suspension, and I couldn't find any e-bikes like this that have it, also no rack, or basket.

The questions I have are, Does anyone know what motor this is?
Do need to remove the cassette to take the motor cover off?
I can get a puller for the motor cover, but if there is some kind of retainer hidden by the cassette, I don't want to break it. I will have pics of the bike next time I am over there.
I watched many YouTube vids on taking these type of motors apart, but they are all a little different, the closest I saw was the Bafang 750 as far as I could tell.

 

[amberwolf]

You'll have to remove the cassette to find out without risk of breaking things. It's easily possilbe for there to be a circlip or other retaining hardware on the outboard side of the cover bearing (some motors do, some don't).

It could even be a ridiculously complex to disassemble design that has a shoulder on the outboard side of that axle larger than the bearing ID, so it *can't* be pulled thru the cover, and instead the entire motor has to be disassembled to get the axle out and then thru that bearing, to be able to access the cover bearing and remove/replace/service it. Not very likely, but possible.

Shimano cassette, so really common cassette removal tool, though you might have to put the motor back in the wheel to get the grip on the cover to use the tool to get the cassette off. (counterclockwise, you'll probably have to use a long-arm wrench and a deadblow hammer on the far end of the wrench to start the removal, if anyone ever actually pedalled the bike it was on as it will likely be too tight to just spin off).
Probably one of these

Cassette & Freewheel

Tools to hold and remove freewheels and cassette lockrings.

www.parktool.com

like this one

FR-5.2 Cassette Lockring Tool

Designed for the removal and installation of most cassette and disc brake lockrings with a 12-spline tool fitting, including Shimano®, SRAM®, and others.

www.parktool.com

It's 12mm axle size, so it'll *probably* fit over the geared motor axle. If not, you'd have to file or drill it out larger. (I did that for a standard parktool fr-1 original version to clear 14mm+ axles; this is the current version of what I used FR-1.3 Freewheel Remover — Shimano®, Etc. ).

 

[s-petersen]

I measured the axle, and it's 15mm,the threaded part is 11mm. There are 6 magnets in the cover if that helps identify the motor, I will look into getting the tools. I ordered the tools...

 

[amberwolf]

There are 6 magnets in the cover if that helps identify the motor,

Most geared hubmotors have those, they're used to trigger the wheel speed sensor (since a typical geared hubmotor without these can't be used to measure wheelspeed, only the speed of the motor itself, unlike a DD hubmotor).

The parts of the motor casing that you don't show at all would typically have the info to identify it.

If it was not engraved in or cast into the metal (most of them are) but only painted on or a sticker, then the repainting would have obscured that info.

Beyond that, you could find out what bike it was originally, from the owner, and then look that up to see what the builder claims was installed on it.

 

[s-petersen]

My friend found it on the side of the road during junk week, the controller and wheel bearing were bad, the battery was good, it's seen a rough life, but worth bringing back, the bike was repainted, and the motor didn't have any info on it (I think) I will have to take pics if it when I go back. I tested the motor with the controller and surprisingly it had a Hall sensor error, which is fine, as it wasn't connected, (waiting on a connector) but the motor worked without it.