Super Rocket A65 TLS front brake rattle

[lawnmowerman]

Hi All

I have a 1969 BSA/Triumph TLS front brake on my SR. Does anyone else have the same setup as I find that there is a really annoying rattle between the tab which sticks out the side of the RH fork lower leg and the locating slot in the brakeplate. It stops immediately when I gently apply the front brake but makes a helluva noise on tickover with the brake off.
I wondered if there was a sprung shim which should be fitted - if not I will make one up and epoxy it to the non-thrust face of the fork tab. The other thing I thought of doing was to drill and tap the non-thrust side of the brakeplate slot and fit a small allen screw with a locknut.
Any thoughts or suggestions gratefully received.

Jim

[tombeau]

Common problem.
I even had an mOT inspector fail me on it...he insisted it was the front bearings clonking, then didn't like looking stupid.
At one point I had a broken bit of hacksaw blade wedged in there, secured to the fork leg by lockwire through the hole..
Next time it bugs me I'll have another go

[beezalex]

If the brake plate is rattling on the tab, your plate retaining nut has likely backed off.  The brake plate should be fixed to the axle.

[tombeau]

You're right Alex, it should. Even when tight they can rattle a bit. depends on how tight a fit the lug is. In use it wil move the ba'hairs distance ´til it hits the lug and stops.

I've got a box spanner the right size for mine so can bang it up tight as can be. Still rattles a bit.

When I was getting the drum skimmed, it took having the wheel clamped in a lathe, a box spanner and 4 foot bar to get it off. it had seized tight and corroded with road salt, but still had rattled a bit on the bike.

Cheers,
Tombeau

[trickytree]

Have you extended the tab on the fork leg? There a tad short for the brake plate, many folk leave them as is but I welded mine and filed it to fit, making sure it was a nice snug fit.

[beezalex]

If the brake plate is rotating on the axle despite the nut being tight, then it has probably been loose so long that it has worn the shoulder down and it needs to be shimmed back to where it's tight.  It really should not float.

[lawnmowerman]

Thanks guys. I am not really sure what nut you are referring to and how it would affect the problem. The brake plate has no side to side movement but the movement is rotational and when the brake is not applied the brake plate chatters as the fork tab is a loose fit within the brake plate slot.
I can understand Trickytree's fix by building up the tab with weld and filing to get a snug fit and that is a great idea if I have to strip the forks in the future but I am really looking for a quick fix as summer is approaching and I want to get some riding in. A piece of broken hacksaw blade is a good idea Tombeau if I can stop it falling out - Araldite perhaps?
I have posted a couple of pics of the brake to avoid any confusion as to the type.

Jim

[trevinoz]

Jim,
          There is a large nut which secures the brake plate to the axle and has a tendency to come loose, mainly, I think, because most blokes don't have the tube socket which fits, and tighten the nut with anytjhing which comes to hand, such as a cold chisel!

   Trev.

[tombeau]

The bit of hacksaw blade was used as it had a hole where it attaches to the saw frame. This was used to lockwire it. A piece of shim steel could be drilled and fitted quite neatly. At the time I used the broken bit of hacksaw because things like that used to send the local rivet counters apoplectic
As its such a small gap, a few turns of black insulating tape, or a bit of heatshrink would probably tighten the gap, and do until you next had the forks off the bike.
You're right Alex, I think its more about the size of the stub on the forkleg rather than the nut on the hub.
Cheers,
Tombeau

[lawnmowerman]

Thanks Trev - the penny has now dropped. I will take the wheel out and check the brake plate securing nut first and tighten with a box spanner - fortunately I have a good selection so I will probably have one which fits. As a temporary fix I will glue a shim on the tab to stop the rattle and build up with weld and file to fit when I next have the forks out.
I have only just noticed the problem so hopefully it has not been loose for long so has not worn out the shoulder.

Thanks also to Tombeau, Beezalex and Trickytree.

Jim

[A10Boy]

I have the same type of brake on my A10. I had a local engineering shop build up the slot on the brake plate with alliminium weld then I fettled it back to fit just right. It only needed an additional 3/16 or so built up. This method removes the need to strip and repaint your fork legs. I had them infil the gap between the lug slot and the cable slot for additional strength and you would never notice it unless you knew it had been done.

[lawnmowerman]

Spot on guys. Just took the front wheel out and the nut was finger tight. I had to tap it round with a small chisel as I did not have a box spanner to fit (sorry) The brake seems to work better now and the rattle has gone. I suppose the slight play in the brake plate stop has an effect on the nut over time and loosens it up. Would Loctite be a good idea?
Does anybody know which size box spanner will fit and I will order one.

Jim

[trickytree]

Nut is 1-1/8" AF. I bought a New Britool deep socket of the bay just this week....£7 inc postage and it came real quick. You shouldnt need loctite if its tightened properly.

[trickytree]

PS...when you tighten the nut make sure the plate/shoes are centralised by applying the brake as there is a little clearance in the brake plate hole.

[beezalex]

You may have trouble fitting a box spanner on the nut since the nut is recessed.  As TT sez, a deep socket seems to work best.