Front brake cable performance

Does the brake cable have a brake light switch in it by any chance? I found these to be a problem. First they let water into the cable. then they allow the outer to compress to work the switch. They are quite thick cables also and that seems to create drag in the action.

On BSA and Triumphs with their TLS if you fit the wrong handlebar lever you get the same. Their are 2 different fulcrum distances on Brit levers, 7/8 and 1 1/8, for the TLS BSA Triumph went to 1 1/8.

You don't mention whether you have fitted new shoes or have the brake plate stiffening kit. It's very unlikely to be the cable seeing that you have tried 2 others.

Mike,

Just wondering how you set the link rod as it all to easy to set it too long or short with used shoes.

What I would do is measure current length of rod top of clevis pin to top of other pin, now take both pins out and remove adjustable rod.

Replace pins, get ring spanners on both brake cam nuts and get a friend to turn both clockwise to apply brakes, while held in this position again measure dimensions between pins as earlier - if needed adjust to the latter distance and both should bite at same time.

regards Martin

Mike

The gold plated solution would be to buy a stiffening kit, fit new shoes with thicker brake linings and have them machined when assembled in the brake plate to match your brake drum. You will then have a brake with bite and a solid lever when adjusted properly. A costly solution but what price would you put on your life in an emergency stop situation?

The early brake plates without the stiffening kit were notoriously spongy and diabolically poor due to the inherent pp design. The idiot who designed them as a 'evolution' from the single leader obviously didn't understand why the original design had a linking bridge between the two pivot points for the brake shoes.

I spent many years on my Commando with the 2LS front brake without the bracing kit. It worked alright and I couldn't see any improvement being gained by fitting the bracing kit. The spindle bushes and cam bushes are substantial and a bracing kit would not solve the problem Mike has. If the lever comes back to the bars then there is something not adjusted properly. My money is on the adjustment of the clevis rod between the two cams. As Martin says apply the same amount of pressure to two ring spanners on the cams with the rod removed. Then, with your other three hands, adjust the length of the clevis rod until the pins just slip in (with the clevis rod at its shortest to take up any wear/tolerance in the pins) Friction in all the bushes makes a great difference to these brakes working well. while there doesn't need to be too much grease around, some is needed.

Previously david_evans wrote:

I spent many years on my Commando with the 2LS front brake without the bracing kit. It worked alright and I couldn't see any improvement being gained by fitting the bracing kit.

So have you actually fit a stiffening kit? Unfortunately the spindle bushes and cam bushes are not substantial and flexing does occur. My experience with this TLS brake on numerous bikes over the last 30 something years tells me that it does make a difference.

I do take your point about the rod adjustment however, I have assumed that Mike has adjusted them correctly.

If you have the early steel bar levers sometimes there is a tiny gap between the perch and the bar that allows flexure, but usually its an accumilation of factors , linings not tight to the shoe, not bedded in, uneven lining thickness ( more wear on leading shoe), not enough play to allow centering, weak cable inner or outer, wear in bushes,structural flexure, distorted brake plate,brake plate being side loaded by the fork stop, eccentric drum,clutch lever substituted for brake ( they were different!),I'll stop now before I become a bore, oh, too late.

I have been working on mine and a light pressure on one side of the plate allows the brake to be adjusted much further, so there must be a twist in there-----somewhere.

Mike,

there is still one more thing to do; Take up the slack in the cable till the shoe just rubs, then head out on the open road, gently apply the brake and bed the shoes in over a few miles on the straight bits - bet you will have some slack to take up in the cable then and hopefully an improvement.

you haven't by anychance had removed the shoes from the backplate and accidentally swapped them round?

good luck

martin