This is what I did regarding disc brakes. I wrote it up and posted it on the Coventry Section website. Good enough to produce a looong black skid mark to avoid hitting the car that pulled out in front of me.The story about milk float brakes (and remember floats=very high loads, steep hills and no engine braking) was related to me as AM4 now AM4 was`responsible for most racing brakes in the 60's and later I have seen Ron Kemp's flash Bramptons bent (the two tubes nearest to the lower axel casting) after a Silversone meeting and following that event he added a cross bracing. Personally I had a spring shatter in the brake from squeel (luckily Ron got me to copper wire the centre up). Now banned because of asbestos Safetec supply a 'replacement' which I have used since but with a new ROAD bike on the cards i am wondering what to use.
If I was to go away from 7" drum (and even a non rivet counter like me would hesitate) its an obvious choice to add a disc (or two) cheap and effective, Of course back in the day we tried other options.... (thats a BSA 190mm)
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What I now see is that the "dips" on the shoes are placing the linings away from the design ideal of 90 deg ,being biased much nearer the pivot t
......actual best method is to assemble up the shoes, cam, serrated washer, brake lever, nut and washer.......then wire tie the end of the arm in the correct direction as if the brake cable was pulling on the brake lever.......this by not more than 10 mm of travel.....cut the shoe lining down till the same size as the ID of each drum......
That became painfully obvious with the yet to be ridden Lighting replica. With Neal’s shoes and heat treated alloy brake plates, next in line was that mount. Without the existence of the front mudguard stay, when the front brake is applied, you can see the leading edge of the mudguard move downward because the FF32 is bending. How does the FF32 bend without moving the fork blades (right where that spindle is located)? Do they move enough to make a difference….. I have no idea…in its current condition there is no convenient way to hang an indicator on there. When assembling the girdraulics, they should drop under their own weight. My gut feeling is that with the FF32 deformed the same amount, that would be less likely. Would it make a difference to the girdraulics performance under heavy braking. Probably not, but that might depend on the state of the bushings.,the balance beam mount is too flexible,
David
either a thicker FF32 or add a brace