The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: gvw on 18.04. 2021 21:39

Title: 1959 A10 super rocket front brake upgrade
Post by: gvw on 18.04. 2021 21:39
The bike currently has an 8” full width hub and 11/8” shoes on a sls brake.

I’m looking for more stopping power and see many folk have upgraded to tls brake but after reading many posts on the subject I’m still a little confused

I see there was an Eddie Dow Duetta2 brake plate made for the job but it seems these are rarer than hens teeth so I was looking at the later Triumph/BSA 8” full width hub tls brake

What I’ve learned is that the brake plate or fork leg need to be modified/built up in order to prevent the brake from rotating - I’m ok and understand this.

What I’m struggling with is the brake shoes as the tls brake shoes are 15/8” wide which I’m guessing are too wide for the existing hub.

Is there any other solution other than fitting another wider hub that is suitable for the wider shoes?

Thanks in advance
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: mikeb on 18.04. 2021 22:29
I think that's about it - Duetta brake plate or later TLS plate and hub.
yes the standard A10 FW hub can not take the wider TLS shoes (the inner of the shoes/linings will be attacked by the spokes).
the half width brake gets better press around here that the full width hub, tho it wouldn't be worth changing just for that.

I got the whole 69 TLS wheel (rim, hub and plate) which fits straight on with the A10 axle. (and build up that slot in the plate) That way the A10 wheel is retained so it can go back to original.

Some people on the forum have success with the standard A10 setup when new softer linings are arced and the drum trued up. And a longer brake arm. I tried all that without much success (tho my skills are a bit poor). TLS much better.

EDIT: someone on the interweb has posted their work on converting a standard brake plate to a TLS setup with the narrower shoes. I can't find the link right now tho can later if you wish. But there is heaps of engineering skill and tools required.
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: gvw on 18.04. 2021 22:37
Thanks Mike - I wondered if I was missing a trick  *????*
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: mikeb on 18.04. 2021 22:50
Quote
I wondered if I was missing a trick
no more than the rest of us A10 owners  *conf*
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: orabanda on 19.04. 2021 03:39
Also check that your hand brake lever has the 7/8" centres between the pivot point and cable end.
This will give you maximum leverage force at the cable (24% greater than the 1 1/8" lever pivot).
Richard
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: Gearbox on 19.04. 2021 08:13
Seen pictures of racing Goldies that have the brake arm reversed. Must improve things or they would not have done it. Guess it would work on the standard A10 brake as well.

Thinking of mods to my 190mm brake and need to do some research into reversing the arm.
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: Sav on 19.04. 2021 09:07
Strangely enough, bought a replacement bellmouth from Surrey Cycles last week and was looking at this.

https://surreycycles.com/michaels-bsa-corner-2/

Mega-pennies, but being able to stop might be worth it one day.

Does not appear to have the fork lug so not sure it would be any good for an A10
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: mikeb on 19.04. 2021 09:22
Gearbox - I reversed the brake arm on my B33 to some modest improvement - there are lots of threads about it. But there was no easy way to do this on a FWH super rocket as you can't just rotate the brake plate due to the peg and slot anchor arrangement (rather than the stay).

DIY Duetto: https://www.flickr.com/photos/30920056@N05/sets/72157629892320000 (https://www.flickr.com/photos/30920056@N05/sets/72157629892320000) for those with the skills and machinery
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: gvw on 19.04. 2021 12:02
Also check that your hand brake lever has the 7/8" centres between the pivot point and cable end.
I will check this - thanks
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: Triton Thrasher on 19.04. 2021 17:55
The VMCC brake trick for single leading shoe front brakes is to remove lining material from the trailing end of the trailing shoe: up to 2/3 of it.

Worked a treat on my Norton 8” SLS.

Home modifications to your brakes can be dangerous, of course, so I’m not advising anyone to do anything.
Title: Re: 1959 A10 super rocket front brake upgrade
Post by: BagONails on 27.05. 2021 04:16
The VMCC brake trick for single leading shoe front brakes is to remove lining material from the trailing end of the trailing shoe: up to 2/3 of it.

Worked a treat on my Norton 8” SLS.

Home modifications to your brakes can be dangerous, of course, so I’m not advising anyone to do anything.

Been reading this thread with a lot of interest as I'm not at all happy with my standard brakes.

I can see how doing this could increase the mechanical advantage in the system, possibly allowing more force to be directed at the leading shoe and more pressure (force / area) over the reduced area in contact on the trailing shoe.  Maybe this also helps the fabled self servo action to take effect, something that seems pretty elusive in my case.

I will hold off on going this far until I've skimmed my linings to match the drum dia and got full contact all over, then see how we go.  I'm closer than when I started, at least the linings are actually contacting the drum now. *eek*