Twin Leading Shoe problem

[Oggers]

Gents

66 Bonnie is fitted with a TLS - Twin Leading Shoe. Essentially on application of the brake, the forks judder and there is quite a bit of chatter from the brake knocking against the retaining tab on the offside fork. I have checked the head bearings - no problems there, so I am guessing it is the brake itself somewhere. I have little experience of these things, so some advice as to any adjustments I need to make or what to look for would be most appreciated.   

[iansoady]

Have you set it up properly so that both shoes touch the drum at the same time? It's a bit complicated to explain but essentially you disconnect the linkage between the 2 shoes then apply both fully with a spanner on the spindle nuts. Then you can set up the linkage so that the clevis pins just slide in.

Other faults may be slack in the pivots / cams / wheel spindle fit in the backplate.

[Oggers]

Ian

No - haven't touched it at all. Was waiting for advice before I do so! Many thanks for the steer though.

[R]

1st step with any braking problem is to take the shoes out and eyeball them.
If they are worn/ridged/knackered, there is not much mileage in persisting with them ?
Rusty linings or excessively dusty or grease leakage or out of round are other possibilities.
Hopethishelps.

[Oggers]

Have since disassembled. Shoes like new, inner surface fine, linkage fine. However, the large recessed hex nut securing backplate was not tight, and as Ian states, pretty sure shoes were not "balanced".

[iansoady]

That slack nut would give you the judder, but obviously you need to get the adjustment right as well.

You do know about leaving the spindle nut slack, putting the brake hard on then tightening the nut to centralise the shoes?

[Rex]

Good advice for SLS brakes but as the adjusting rod will likely be adjusted after the spindle nuts are tightened it's not so relevant on TLS.

[iansoady]

True, but I'd get the linkage about right then do the centralising then readjust the linkage. A bit of a faff but should get good results.

I have to say I've only had one bike with a 2LS (Triumph unit 500) but it worked very well after tweaking it.

[mini-me]

Those Triumph 2LS brakes were among the best; when I worked for the Met Police, [or polis or da feds as is now PC  talk] I had one know it all police rider who always tried to tell me that the front brake lever should not have so much travel, normally we'd set them up so they didn't bite until almost right at the bar. I let him get on with it after he came the heavy, it wasn't long before it threw him off.
$%^

[TGR90B]

I've got one on my T100R. Faultless braking.

[Rex]

Not only very good but very attractive too. Shame the groupthink of Slumberglade Hall changed the design to the ugly conical hub version.

[Oggers]

Where I am at now is as follows

Reassembled with large 31mm or so recessed nut done up tight
Not loosened the spindle nuts
Front spindle arm pulled to brake on position as far as it will go - held with wire 
Link piece fitted to front spindle arm
Rear spindle arm pulled on as far as it will go
Rear of link piece adjusted so clevis pin slides through.
Lock nut done up

Brake fitted up again. Feels far better with the front wheel off the ground, but not been on a run just yet.
 

[iansoady]

Sounds good. Let us know how it performs on the road.

[Oggers]

Ian

Thanks again for the steer - much appreciated. I am somewhat concerned as the bike has only has 1300 miles after a total resto by the PO. Things like this brake should have been sorted. Only the other week I also had to pull the clutch apart, clean all the plates, dress the splines, adjust the pressure plate as it just was not engaging gear properly. It is fine now, but this is basic stuff. I worry somewhat about what I may find next! Engine should be fine as it went off to a decent builder and it does sound glorious.



 

[Rex]

Only 1300 miles since a "total resto"?
Sorry, that's not a "good" recommendation but a worrying one! Poorly adjusted brakes and clutch on something that some one spent a lot of time and/or money on are possibly good indicators that his enthusiasm surpassed his skill levels.
I'd spend a bit of time going over the whole thing carefully if I was you.
Brakes and clutch are pretty basic stuff to get wrong.