My BBSHD has 8 of these M4 threaded holes on the back of the output gear.
They are going to be very handy for me for fixing a new bracket for the old-fashioned chain guard that goes with my bike.

But I'm stating to get curious - what are they for?
I presume Bafang did not go to the expense of drilling and tapping these just for fun.
It seems they are "blind". They've been drilled and tapped in one part. I's not another part at the bottom of them.. or is it?
Does anyone care to speculate?
Perhaps someone who has disassembled one of these can shed some light on the matter?
They are going to be very handy for me for fixing a new bracket for the old-fashioned chain guard that goes with my bike.

But I'm stating to get curious - what are they for?
I presume Bafang did not go to the expense of drilling and tapping these just for fun.
It seems they are "blind". They've been drilled and tapped in one part. I's not another part at the bottom of them.. or is it?
Does anyone care to speculate?
Perhaps someone who has disassembled one of these can shed some light on the matter?