Bafang BBS01 not fitting...

Mar 12, 2020
28
2
Just trying to fit a Bafang BBS01. It won’t slide in.

My boyfriend thinks he can fix this by ruining the frame a little.

Is that the right thing to do?

Any help appreciated!
 

Woosh

Trade Member
May 19, 2012
13,306
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Southend on Sea
wooshbikes.co.uk
Check inside the bottom bracket shell where the tubes are welded together for excess welding.
He will have to file off any welding that protrudes or sticks out.
I use a dremel in the workshop for this but if you don't have it, sandpaper takes more time but will also work.
If you still have difficulty, post some pictures of inside the bottom bracket tube here.

 
Mar 12, 2020
28
2
Check inside the bottom bracket shell where the tubes are welded together for excess welding.
He will have to file off any welding that protrudes or sticks out.
I use a dremel in the workshop for this but if you don't have it, sandpaper takes more time but will also work.
If you still have difficulty, post some pictures of inside the bottom bracket tube here.

 

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Woosh

Trade Member
May 19, 2012
13,306
10,468
Southend on Sea
wooshbikes.co.uk
Leave the grooves alone!
dremel only the welding spots, not the thread!
You want to be able to put the bike back to how it was and move the kit onto another bike some day.

You want to smooth out the welding spots so they don't get in the way when you push the motor in.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
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Tyne and Wear
I had similar issues when fitting my kit. Although I didn't need to Dremel any welding spots off, a spray of silicone inside the bottom bracket, plus a rocking action as I pushed the motor unit in, helped with installation.
 
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Reactions: Woosh

Woosh

Trade Member
May 19, 2012
13,306
10,468
Southend on Sea
wooshbikes.co.uk


clean out the middle of the shell with a piece of sandpaper - you'll see the welding spots better.
 

Woosh

Trade Member
May 19, 2012
13,306
10,468
Southend on Sea
wooshbikes.co.uk
try also what fordulike suggested with a little grease - you will scratch the black paint a little but you won't hurt the motor.
 

Fordulike

Esteemed Pedelecer
Feb 26, 2010
3,458
1,323
Tyne and Wear
Also, once your boyfriend has managed to fit the motor, be sure to use the correct installation tool to tighten both inner and outer locknuts. If you don't tighten these down sufficiently, you will find the motor will shift about with use, and create problems further down the line.

Another tip: the motor fixing plate has one side with knurls. These knurls face and dig into the bottom bracket and help prevent the motor from shifting when operating.
 
Mar 12, 2020
28
2
Ok it’s in!

But it wouldn’t fit any of my 3 front bike cogs so now I just have the 7 gears.

I hope that will be ok.

Also I hear a lot of swearing from my boyfriend because apparently the threads are rubbish.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
You can fit a double to the BBS if you want lower gearing, 104bcd adapter spiders are available. The smallest inner chain ring you can fit is 32t.