BRAKES WHAT'S NORMAL

[JonE]

Thanks Jim - was looking at how to do those bits today.

Ref my photo in post #29 of rear brake lever position. I now feel it's impossible for a diagnosis of cams being wrong sided for that scenario. I've been faffing for a couple of sessions and of course, you learn best whilst doing that. But what becomes clear is that when the shoes are resting, full on cam flats, there are 4 possibilities from the cam pair. Two result in the lever facing upright so obviously incorrrect, so that leaves one potential position on each of the cam pair to investigate. The correct one put the lever approximately downward, whilst the incorrect puts it over the top of the axle tube, so it would be impossible for it to move when actuated, despite it being nicely far back.
The factors [that lead to that angle of lever photographed] were solely lack of shimming and wear on the drums, meaning that the cam was adjusted up for pedal travel, but with hardly any slack left before the cam would flip dangerously.

This thread has been fabulously helpful (thankyou all), and the real thing I've gradually learnt is that you need to do ALL the in-drum stuff (3 shimming positions, drum choice) to minimise clearance before even thinking about the cams.