Regarding John’s braking problem in RC194. Are the shoes correct? This may be a fault I’ve met before. They need to be fitted the correct way round, with the brake cam running on the alloy side of the shoe, NOT the flatter ‘U’ steel shoe on the other side of the shoe. It’s what is called a floating shoe. On application, the trailing shoe moves back and becomes a leading shoe. Hope this helps. Dave King, member 4895
The rear brake on a T100SS has a leading shoe and a trailing shoe. It’s easy to get these wrong as they look very similar. They have different part numbers (leading W1406, trailing W1407. It sounds like he has them in the wrong way around. I have a T100R and a T100C with the same brakes and I have no problem locking the rear wheel. Denny Chappell
John Stuart should try fitting the brake shoes the other way round, so that the shoes have the opposite leading edge. The only bike I ever bought new was a 1973 Trident T150V, which came with a full workshop manual. The back brake was so bad that I had to use the front brake to bring me to a halt at traffic lights on a very greasy patch of Mitcham Common Road, resulting in a tumble to the great amusement of a police motorcyclist opposite.
Upon investigation I found that the manual described the shoes as being one way round, while showing a picture of them the other way round, so I tried reversing them and it worked. Alas, Metropolitan Police Z Division lost their sense of humour about the bike over the next couple of years when it gained clipons, rearsets and a tuned motor and I spent the glorious summer of 1976 on a push-bike... Phil
When we checked, we discovered lots of eBay traders offering one type of brake shoe to fulfil both original part numbers ( W1406 and W1407), when they should be different. So this is one of those moments when it is probably wise to consult an actual Triumph parts specialist, rather than sourcing brake shoes online from suppliers who don’t really know what they’re selling. Try chatting to Monty (01822 617010) or Andy (01434 820752). R&F
I think Mr Stuart has dropped a geometrical clanger. By extending the brake lever arm length to the brake rod pivot, he’s reduced the mechanical advantage not increased it. Jim Lugsden
Something I often see in photographs of motorcycles fitted with 2ls front brakes is that the operating arms are not parallel. I have found that setting them up parallel, by shifting the lever around on the splines, gives a much firmer feel and evens the wear on the shoes. If the levers are not parallel then different forces are applied to each brake shoe cam. Theoretically, maximum braking effect is achieved when the cable and lever are at ninety degrees, but it is better to aim for about 80 degrees to allow for a bit of wear on the shoes.
This even worked on Yamaha XS1s, which were notorious for having poor front brakes. As the shoes wear then the levers can be rotated on the splines to return the levers to their optimum operating angle.
I hope someone finds this useful as it can noticeably increase the effectiveness of twin leader brakes, extend the life of the linings and it may just save someone’s life. RealClassic is about the best value motorcycle magazine available, with a huge range of interesting articles on all aspects of motorcycling. Please keep it up! Paul Elliott
Back in the late 1950s and 60s, I and others had similar problems with back brake fade. I had it on my racing Nortons, both Dominator SS models, and on a Manx back brake. After talking to a well-known rider I started to reline my brake shoes (rear only) with a brake lining called AM4. It was a green composite impregnated with alloy material. These linings were known to be a little bit too good, so we were advised to add a slightly longer lead chamfer, and put a longer chamfer on the back end of the lining.
Instead of messing around with fulcrums, pivots, brake rod to brake pedal levers, etc, I think that John could go back to the original Triumph brake layout and try some better linings. It worked in the old days, there’s no reason why it wouldn’t work 50 years later. Mick Madell, member 12,297 Ah, well, odd you should say that, Mick. In our ongoing struggles with conical hub drum brakes – which can be randomly awful or awesome – we’ve noticed that brakes which retain the original brake linings tend to perform better than those fitted with modern linings. We have a suspicion that modern high-tech linings are possibly made of something supersafe which doesn’t generate carcinogenic particles… but which doesn’t generate quite so much friction, either…