Bafang 750watt motor making strange sound (and not working)

[Cyclomania]

So today after a slope I was at a traffic light. Then I tried to get my Bafang motor-driven bike on the highest gear without pedaling going over when it turned green.

So then it started making these strange sounds. And perhaps now it is defunct. Any idea if this can be salvaged by opening the motor up or something like that? Thanks

Here is the vid:

The video does not exist - VEED - Online Video Editor - Video Editing Made Simple

This video might be deleted or expired.

www.veed.io

 

[rick_p]

I wasn't able to access the video, it said it wasn't ready. Strange sounds are never a good sign, but with that said, I've been fooled by clicking and other sounds that turned out to just be the derailleur or loose spokes. So, without the audio recording or other information about the problem, it will be hard to diagnose.

 

[rick_p]

I see this is a duplicate thread of Motor perhaps overextended? where you got lots of responses. Maybe you should delete this one.

 

[Slowchris11]

You need a new Nylon gear for your Motor.
You have chewed up the gears and now have the typical "I started with the throttle at the light's in highest gear and now my motor doesn't move the bike while making strange noises" syndrome.
Didn't you know this always happens if you use a Bafang like that?
You need the special lock nut tool, the Nylon gear, some special plastic lube for it and a little silicone sealer. Good idea to lube all the other bearings (with normal gearing grease) while at it. There is a zillion videos how to do it.

 

[Cyclomania]

You need a new Nylon gear for your Motor.
You have chewed up the gears and now have the typical "I started with the throttle at the light's in highest gear and now my motor doesn't move the bike while making strange noises" syndrome.
Didn't you know this always happens if you use a Bafang like that?
You need the special lock nut tool, the Nylon gear, some special plastic lube for it and a little silicone sealer. Good idea to lube all the other bearings (with normal gearing grease) while at it. There is a zillion videos how to do it.

Yeah I was pushing it a bit. But shit happens.

So basically what to order now is the nylon gear and a silicone sealer? I think I could use some lithium fat for this right? I believe I have the locknut tool I think.

Good to know

About the vid I will try to fix it later. Something seems to have gone wrong there yeah.

 

[Slowchris11]

Do not use lithium grease for the plasic gear. Litium is for the steel gears only. You need a special plasic lube, syntetic or silicone based.
The recommended, red Mobil lube can be used for both.
Bafang uses very little expensive plastic lube and cheap grease for the rest. Any penny counts...
They did not separate these different areas, so grease may mix after some use.
The Nylon get's hard and brittle from mineral oil based grease.
You should be able to get this grease where you order your gear.

 

[Cyclomania]

Do not use lithium grease for the plasic gear. Litium is for the steel gears only. You need a special plasic lube, syntetic or silicone based.
The recommended, red Mobil lube can be used for both.
Bafang uses very little expensive plastic lube and cheap grease for the rest. Any penny counts...
They did not separate these different areas, so grease may mix after some use.
The Nylon get's hard and brittle from mineral oil based grease.
You should be able to get this grease where you order your gear.

I bought the one called internal gear here:

https://www.aliexpress.com/item/1005001792718404.html?spm=a2g0o.order_list.order_list_main.17.34101802UoiKDD

They had no idea what grease/lube to use. Do you have a link?

Thanks

 

[Slowchris11]

They are Chinese vendors, don't know and care even less what they sell.

You need a lube for plastic / metal gears like Mobilegrease 28. You may find it in small amounts at eBay.
Look for "Bafang Grease"

PdsDetailsPage

Mobilgrease 28 ist ein Hochleistungs-Schmierfett mit ausgezeichnetem Verschleißschutz. Das Produkt wurde entwickelt, um die einzigartigen Merkmale eines synthetischen Grundöls auf Polyalphaolefin-Basis (PAO) mit einem organischen (seifenfreien) Schlämmstoff als Verdicker zu kombinieren. Seine...

www.mobil.com

Your usual mineral oil grease will make the plastic harden and break. Silikon grease may work, too.

 

[E-HP]

I bought the one called internal gear here:

https://www.aliexpress.com/item/1005001792718404.html?spm=a2g0o.order_list.order_list_main.17.34101802UoiKDD

They had no idea what grease/lube to use. Do you have a link?

Thanks

Ah, so this is a mid drive/bbs02. For some reason I thought it was a hub motor. As mentioned, you need to always downshift before you come to a stop and especially if you are starting out on a hill.