I posted this a while ago;
https://www.accessnorton.com/NortonCommando/drum-brakes.10690/
https://www.accessnorton.com/NortonCommando/drum-brakes.10690/
brake shoes
- Thread starter seattle##gs
- Start date
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- Oct 28, 2014
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UPDATE... After trying various adjustments and R&R the wheel many times I discovered that I could not get the short arm shoe to touch the drum much at all. So I put a .020 shim between the cam and the foot of the brake shoe. I could then turn the adjuster rod and get identical contact on both shoes. and about 7/8 contact on each shoe. So now I have adjustment capabilities in the adjuster rod which I didn't really have before. I think the short arm shoe showed marginal contact only because of hard braking on the road. Step 2....I cannot leave the shim in the brake plate so I will have to shave off .020 from the long arm shoe. Could not road test it this eve because of the shim but I consider this a success so far. Back at it this Saturday.
The motor started in 5 kicks..we changed the cam from a JS1 to a stock Commando cam.
The motor started in 5 kicks..we changed the cam from a JS1 to a stock Commando cam.
NO, NO -Very DANGEROUS !
.020 SHIM AS A SLIPPER IS NOT RECOMENDED ! why it will wear down eventually and possibly jam the break on, or as it did one of my bikes broke the anchor arm, allowing the brake plate to revolve around with the wheel – don’t shoot the messenger!
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- Oct 28, 2014
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I realize the bike cannot be ridden with the shim in place
- Joined
- Oct 28, 2014
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further update... after measuring the linings I discovered that the long arm shoe was thicker than the short arm shoe...beyond the adjusting range. So I swapped the shoes and ended up with a little adjustment room. To make a long story short, I took it out for a ride and there was a definate improvement in braking. not 3X better but an improvement. And any better braking is worth the effort. Perhaps it will improve further with more use. no squeeks, no grabbing.
Re "Ferodo are the worst for undersize shoes" Ferodo sill do or did supply OVERSIZE brake shoe linings only to recognised Ferodo supplies . . . . . This was how Joe Dunphy and others were able to rivet them to shoes and then skim them down to fit the brake drum.
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Back in the early 80s , I had Norton TLS shoes skimmed by a specialist in Lenham, Kent, UK, for an Dunstall Atlas cafe racer. That gave the best standard drum brake I had used, by quite a way. (The drum was not machined)
Lent bike to a friend for going to the TT: one of the rockers broke on the way( very lumpy cam) , so he rode pillion on my Fastback for rest of trip....
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A tight tolerance bush on the brakeplate is perfect for initial setting up, the lining surfaces will be centralised to the hub brake surface. However as the linings do not wear evenly that bush will become a liability. The leading edge of the lining wears out faster than the railing edge so then a sloppy central hole on the brakeplate will allow a reset of the surfaces by loosening the axle nuts, holding the brake on and keeping the brake on while tightening the axles nuts back up.
So now its served its purpose you can remove the tight tolerance bush or open it out if removing it creates a too large hole. Or change the brakes in some way to make the shoes floating so they self centralise as they wear ala Triumph 67 onwards.
So now its served its purpose you can remove the tight tolerance bush or open it out if removing it creates a too large hole. Or change the brakes in some way to make the shoes floating so they self centralise as they wear ala Triumph 67 onwards.
