In the time I was frequenting the old british iron list, there was a guy in Sweden who was producing an alloy brake plate supposed to improve braking a lot! As I cannot find his contact anymore I installed a rear disc!
I posted the following today on the INOAList at Yahoo Groups in response to an inquiry there. I would question the effectiveness of a stiffening bracket on a properly set up single leading shoe rear brake. On a TLS front brake, absolutely, go for it.
Some thoughts on your rear brake, which I assume is a drum brake.
First, the easiest thing to do.
Assuming your brake shoes are clean and in decent shape, the pivots
are lightly lubricated and the drum is OK, loosen the axle and stub
axle. Have someone depress the brake pedal with some good force to
center the hub about the shoes and while they are holding the pedal in
this position, tighten the stub axle tight and then the axle. This
will help center the drum on the shoes and give you braking as good as
you can get without shoe replacement, drum turning, shoe turning
and/or other diddling. You should do this anytime you loosen the stub
axle or axle. It can make a real difference in braking performance by
increasing the surface contact between the drum and the shoes.
If you want (or need) to go farther, think about relining your shoes,
turning your drum and then turning the newly relined shoes to match
the newly turned drum. Vintage Brake can do the whole job for you if
you send them the appropriate parts. See their website. I think that
Heinz Kegler may do this as well, as may others. Perhaps someone else
can confirm that.
I seem to recall Hobot posting instructions on doing a cheapie shoe
turn by lining the drum with adhesive backed sandpaper and then
turning the drum while the brake is applied to conform the shoes to
the drum. If you don't want to send your stuff off to a professional,
this may help. Give Hobot a shout. Hobot, if my memory is incorrect
and it wasn't you, sorry.
If you have a brake cable with an integral brake switch, throw it
away, now. It flexes way too much to ever give good braking from the
rear. Get a separate switch and connect it to the brake pedal where it
won't interfere with braking. Also, use the shortest cable that routes
well and without interference in your setup. Longer cables result in
curved cables and curved cables flex more, degrading braking. I made
new muffler brackets for the left side of my 850 to allow a shorter
cable to be properly routed for use with my rearsets, resulting in a
definite improvement over the long, curved cable previously there. RGM
advertises a kit to replace the cable with a rod linkage, which should
improve braking by eliminating cable flex. Last time I called them
though, in about January, thay couldn't supply the kit because they
were backordered on one or more parts of the kit, and had no idea when
they would have all the necessary parts in. Also, they say the kit
will only work with rearsets. I can't comment on the kit personally
but replacing the brake cable with a relatively straight rod should
improve braking but it's not as easy to do on a Commando as on other