After servicing my front hub which I posted in Sturmey Archer XL-FDD Service, the drum brake started to stick again. It was getting to the point where I would have to roll the bike backwards to release the brake at red lights, not particularly ideal!
So straight into it, I tore the brake down into bits. Nothing unusual to report from last time though.
As the pivots were already lubricated last time, I figured maybe it had to do with the shape of the cam. I went to file more of a radius onto it, I thought it may be due to a flat spot which might have stopped the shoes from retracting.
The shoes have little metal caps which slide on the cam, you can see they have a slight ridge on them, which I flipped around so they would only rub on new material.
Back together again. So far the sticking has disappeared, and after a few weeks it's still not back. Fingers crossed!