Rear brake issue.

[A10 JWO]

I fitted my newly built back wheel and fitted the brake pedal. Despite having loads of meat on the shoes I am taking up nearly all the adjustment on the brake road. The parts list shows 2 caps         
ref 41-6078 on the 1971 Version of the Thunderbolt. I did dismantle the brake plate when I had it aqua-blasted, BUT I cannot remember if the shoes were fitted with the caps when I assembled the hub. Do they make that much difference ? Thanks.

[JulianS]

If they are original shoes then the pads are essential. They sit on the pivot end of the shoe and are about 1/16 inch thick so have a significant effect on brake geometry.

If the shoes are pattern items I do not know.

[ChrisG]

Yes you will need them. They are a bit weird shaped which makes the edges that slip over the brake shoe 'clip' on, a bit like its got shoulder pads! The idea is the shoes become fully floating so centralise automatically. Note I use the word 'idea' as it should work in theory. In practice??
Have a dig around in your box of bits and see if you find something close. If not they are available at places like Kidderminster M/Cs
Chris

[Servodyne]

In my experience with the Conical rear brake, the standard BSA pivot pads 41-6078 are not thick enough. Consequentially the brake lever has to turn past 90 deg to the brake rod rod before it begins to bite. You can fit a Triumph modified pivot pad 37.4037 which has a plate spot welded onto it to increase the effective thickness and take up the 'slack'.
I think this will sort out your problem.

[JulianS]

Triumph service bulletin showing the modified pivot pad.

[A10 JWO]

All answers appreciated. I have looked at many photos of this model, all the brake adjusters seem to have taken up much slack. Hope fully this tread may also help others. I am considering ordering new shoes with the modified caps from a Triumph parts dealer as the conical hub should be identical on both BSA and Triumph in 1971-2.

[A10 JWO]

I am sitting here with the brake plate next to me, the shoes have quite a bit of meat on them and are fitted with the caps 37-4018. The shoes are actually stamped MCD2 37-4018, can't be original, can they ? The problem remains, too much adjustment required. The drum looks good with no real sign of excessive wear. I have googled 37-4018 which is listed as correct. I am considering ordering new Bonneville Conical Hub shoes with the modified caps ( 37-4037 ). I thought I would throw this open to the readers first, thanks.

[Servodyne]

I would just buy the modified pivot pads 37.4037 first.

I think that you'll find most of the slack disappears.

[A10 JWO]

New shoes and modified pads arrived from SRM today, will let everyone know how it goes.

[A10 JWO]

Fitted new shoes with modified Triumph pivot pads supplied by SRM ( £4.00 ). Could not get the brake plate back in the wheel. Tried with standard pads, still too much adjustment. I ground about just under 2 mm off the modified pads. Now have a very nice back brake, job done. Hope this helps someone else.