BBS 02 Centre Shaft Screws

[TriCrossE]

Hoping for some guidance from someone who has changed the bearings inside the BB shaft of a Bafang BBS 02.

On the non drive side there are 2 of these centre shaft screws, one loads the thrust bearing and the outer locks it all in place.

Is there a tool or a method for this? I can reassemble with virtually no.play but I can't get enough purchase on the outer nut to lock it all in place and therefore after riding it begins to undo again.

The retailer I purchased from apparently has never even opened one up so no help there.

Thanks in advance

 

[wheeliepete]

This is the tool for the job, I made my own from a piece of steel tubing. You could try tightening the outer lock nut with a suitable punch.
https://www.greenbikekit.com/bafang-8fun-spare-parts/bafang-mid-motor-repair-parts/bafang-8fun-bbs01-bbs02-clutch-lock-nut-spanner-wrench.html

 

[Fordulike]

I use right angled needle nose pliers and thread locker.

 

[TriCrossE]

Hoping for some guidance from someone who has changed the bearings inside the BB shaft of a Bafang BBS 02.

On the non drive side there are 2 of these centre shaft screws, one loads the thrust bearing and the outer locks it all in place.

Is there a tool or a method for this? I can reassemble with virtually no.play but I can't get enough purchase on the outer nut to lock it all in place and therefore after riding it begins to undo again.

The retailer I purchased from apparently has never even opened one up so no help there.

Thanks in advance

 

[TriCrossE]

I wonder if this may do?

 

[Fordulike]

The problem is, that ideally you need to tighten the first nut to take out the play in the thrust bearings, then tighten the second nut to stop the first one from loosening.

It's difficult to lock down the second nut, without overtightning the first nut and crushing the bearings.

That's why I use threadlocker, which allows me to tighten the nuts just enough to take out the play in the thrust bearings.