Bafang 8fun SWXK 36v 250w front hub query

[Mrg10]

Evening all,

I’m new to this forum and was looking for some advice.

I recently inherited a Bafang 8fun SWXK 36v 250w front hub, with the necessary controller and battery.

Whilst I’m more than confident with traditional bikes, I am new to the world of e-bikes.

With regards to my query, I have attached a video of the motor in action.

M G

Explore M G’s 2 photos on Flickr!

flic.kr

I am unsure if the clicking sound is to be expected? And if the general noise of the unit is normal, as to me it sounds like the bearings could do with replacing.

Any help will be appreciated.
Thanks

 

[saneagle]

It shouldn't make that noise, but is it coming from the motor or something touching the spokes?

 

[Mrg10]

Hi, nothing is touching the spokes and it’s definitely coming from the actual motor itself.

 

[saneagle]

Motors are normally pretty reliable unless somebody has been fiddling with them. Assuming that it hasn't been opened, have a look at the disc retaining screws. there should be a spacer behind them when there's no disk, otherwise they can touch the motor. Try removing them to see if the noise goes away. Your video doesn't show enough detail, but from what I can see, it doesn't look quite right.

 

[Mrg10]

Thanks for the response, after reading your post I remembered I fitted new tyres and clearance was tight. The vent spews were touching the caliper, so I clipped them back and now the clicking has stopped!

With regards to the disc brake bolts, a spacer wasn’t present so I have removed the bolts for now.

I’m now left with this… https://flic.kr/p/2oAMDXQ and would be grateful to understand if this sounds “normal” or possible wear from the bearings.

 

[AGS]

That’s sounds like graunchy bearings to me. It’s easy enough to dismantle the motor and inspect them with the right tools. You will probably need a bearing puller if they need to be replaced.

I think it’s worth taking a look at an unknown motor. It may have had water inside.

 

[Mrg10]

That’s sounds like graunchy bearings to me. It’s easy enough to dismantle the motor and inspect them. You will probably need an impact driver to loosen the screws. And a bearing puller if they need to be replaced.

I think it’s worth taking a look at an unknown motor. It may have had water inside.

Thanks, will I find any “how to” guides on this site as a back up to work from?

 

[Nealh]

One has to be careful if the rotor screws are removed as water /moisture will enter the motor in the wet and will rust everything solid, if not using rotors then refit the screws ensuring they are water tight , employed some ptfe tape or thread lock to the threads.

Often the LHS of the motor casing will need the sealed bearing replaced if it is graunchy, it will need the inner motor removed . Access is form the RHS and may need a special tool or make one up, we need to see pics of the hub face.

 

[Mrg10]

Fortunately, I have found an ebike repair specialist nearby, so I think the most sensible thing to do would be to drop it off and let them inspect the motor. Thank you all for the responses.

 

[saneagle]

Fortunately, I have found an ebike repair specialist nearby, so I think the most sensible thing to do would be to drop it off and let them inspect the motor. Thank you all for the responses.

Don't do anything yet. Many motors go noisy when not used for a long time, then go quiet again after a bit of use. I've even had brand new motors do that.

Check whether the disc holes are blind or go right through by poking something into one. If they go through, they must be sealed to stop water getting in.

If you take that motor to an ebike specialist repairer if there is such a thing (never heard of one before), it would cost more than what the motor is worth to fix anything that they deem is wrong with it.

Can you please give details of this ebike repair service?

 

[Mrg10]

Don't do anything yet. Many motors go noisy when not used for a long time, then go quiet again after a bit of use. I've even had brand new motors do that.

Check whether the disc holes are blind or go right through by poking something into one. If they go through, they must be sealed to stop water getting in.

If you take that motor to an ebike specialist repairer if there is such a thing (never heard of one before), it would cost more than what the motor is worth to fix anything that they deem is wrong with it.

Can you please give details of this ebike repair service?

I shall refit the disc rotor bolts with a spacer and ptfe tape as a precaution. I will also use the bike for some commuting duties this week.

It does function correctly, I’m just in the unknown with regards to the general noise they make.

The shop I found, although I haven’t called to determine if they worked Bafang motors …https://www.fettle.cc/services/e-bike-servicing-repair?gclid=EAIaIQobChMItoPN-7_5_gIViqzVCh172Aw0EAAYASAMEgJDkPD_BwE

 

[saneagle]

The shop I found, although I haven’t called to determine if they worked Bafang motors …https://www.fettle.cc/services/e-bike-servicing-repair?gclid=EAIaIQobChMItoPN-7_5_gIViqzVCh172Aw0EAAYASAMEgJDkPD_BwE

I like to have an open mind. Somebody needs to test them out, but the instinct in me says that's going to be a nogo.

Let's look at worst case scenario with your motor: Water got in and made some parts rusty and possibly damaged bearings. You can't make it worse by riding it. Two things are going to happen. Either the surface rust will wear off and everything will be nice, or the rusty bearings wear out rapidly and need to be replaced. Either way, a week of riding won't do any harm and will give you the answer to which it is. If the bearings do expire, they're very cheap to repair, but those motors can be tricky to open, depending on which version it is. I need to see a picture from the wire (RH) side to say more about that.

Please come back and report what happens.

 

[Mrg10]

I like to have an open mind. Somebody needs to test them out, but the instinct in me says that's going to be a nogo.

Let's look at worst case scenario with your motor: Water got in and made some parts rusty and possibly damaged bearings. You can't make it worse by riding it. Two things are going to happen. Either the surface rust will wear off and everything will be nice, or the rusty bearings wear out rapidly and need to be replaced. Either way, a week of riding won't do any harm and will give you the answer to which it is. If the bearings do expire, they're very cheap to repair, but those motors can be tricky to open, depending on which version it is. I need to see a picture from the wire (RH) side to say more about that.

Please come back and report what happens.

Here is a picture, in the meantime I’ll continue riding and report back. Thanks

 

[saneagle]

Here is a picture, in the meantime I’ll continue riding and report back. Thanks

That's a QWSXK5, the worst type to disassemble.

It might or might not have a tiny grub-screw into the thread in the surface next to the spoke ends.
It can be left-hand or right-hand thread, so when it's tight (always is), you don't know which way to turn.

If it does need opening, come back and ask agaim for tips.