So mate, how does the width have no bearing on this?
"Braking effort is a function of friction of the linings on the drum"
Friction area?
Oooh I just want to add, some of England's best brakedrums are solid, heavy cast iron drums. Don't be too quick to label them as "lemons". (Think dimensional stability under temperature variations).
When I feel the weight of my cast iron Velocette VM front drum I think... "jeezus, why so heavy fer gawd's sake?!!!" But then when I ride it, I realise just how good a simple single leading shoe 7" brake can be, I forgive the weight, - those engineers knew their stuff, Velo did have the 'engineering class' to make the hub in 2 halves... braking side cast iron, the other half, aluminium.
One of the problems (IMHO) with the conical TLS brake is that it had a shrunk-in iron liner in an alloy hub housing, -and then they compounded the problem by having cruddy pressed steel brakeshoes, with all the heat distortion that comes with all that.
And then (insult upon injury)... they put in a bluddy brake switch inline in the cable, so you had to squeeze out that 'play' before the cable even had any effect at all on the cam levers!
And we wonder why...