I have recently been contemplating the optimization of the performance of drum brakes for my classic racing Aermacchi. I have also been in discussions with a couple of friends regarding improvements to a drum brake for a road bike.
To put this work on a more technical but easy to use basis I have developed a small computer programme to evaluate the effects on braking torque of changes to the overall drum and backplate geometry and changes to the coefficient of friction.
As this software might be of use to others I have made it freely available and it can be downloaded from the freeware section of my web site at www.tonyfoale.com
It is a single standalone .exe file so just download it to a directory of choice and run it directly or make an appropriate shortcut to it. No installation procedure is necessary.