On the Oct. 1964 Mini 850 I'm currently restoring I intend to use the original single-leading-shoe brakes. I had considered fitting the 998 Cooper 7" disc brakes if only to reduce the need for frequent adjustment, but I don't have any of those and I do have all the drum brake parts. I want to stick with the 3.5" x 10" wheels and 145/80 x 10 tyres.
Part of the fun and enjoyment of an early 850 is the retro driving experience, if only to remind us how much auto-technology has moved on in over 50 years.
In fact the drum brakes are not as bad as some claim due to the moderate top speed and the poor acceleration. After hard braking from, say, 60 mph, it takes so long to regain that top speed that the brakes have cooled down a bit.
For competition we used to fit harder linings (Mintex M20 or Ferodo VG95 material) and that worked fine. It was not until the Cooper 'S' came along with twice the power of the 850 that the bigger and better 7.5" disc brakes became necessary. To slow from 95 mph generated a lot of heart and the ability to get back to that speed in a very short time dictated better brakes.
In fact, when I got my first 850 Mini in 1963 I sold my 1950 Ford 3.6 litre V8 Pilot which did almost 90 mph and had rod-actuated rear brakes and hydraulic front drums. You certainly had to anticipate the need to reduce speed in good time
. The 850 brakes seemed marvellous back then.