The BSA A7-A10 Forum
Technical (Descriptive Topic Titles - Stay on Topic) => Frame => Topic started by: Peter Gee on 20.12. 2017 07:03
-
Hi Folks,
I am stumped about which shoes to get for my BSA A10 front wheel I am building. I have a FLANGED 8" Tri-BSA type hub from 1966 on Triumph. I have a 8" BSA SLS brake plate from early A50/A65 (1964/65) models BSA Part 42-5853 and from very late A10's . I have also studied Bulletin no 21 of 1961 suggesting 68-5524/5 for fully floating brakes.
This is not Las vegas auction correct but I have a spare flanged 8" TRI-BSA hub and wheel so thought to use that.
There seem to be a rather dizzying selection of brake shoe numbers, both Triumph and BS
Thanks
Peter in Kenya
-
You can use the flanged hub with single leading shoes from the 1966/67 Triumphs, they are 1 5/8 inch wide. Done it but you need to use the BSA brake plate not the Triumph which does not have enough metal to engage with the BSA fork properly
Or you could consider using the twin leading shoe brake with the flanged hub- fitting details in other threads.
-
Dear Julian indeed I have a pair of Triumph 1 5/8" shoes W1704/5 which are SLS 8" flanged hub I believe. But will these really mate to BSA 42-5853 in the correct leading/trailing configuration as shown in Bulletin No 85 Nov 61?
To me these wide Triumph shoes will only fit if they are reversed in trailing/leading to the illustration, due to the Dogleg cast of the W1704/5 shoes.
I seem to believe I will be stuck with 68-5524/5 with the brake plate I have?
-
I tried the flanged hub with the wide Triumph shoes in the early 1990s.
You will need to trim the plate pillars as indicated in the photo to get the shoes to fit the BSA brake plate.
-
Thank you Julian that is exactly what I deducted after various trial fits. I would think the extra 1" (1/1/8 effectively some 27% % increase in braking surface is worth it.
Can you recall what cam and fulcrum pin to use?
-
Julian, there seems to be a 42-5853 brake plate and another "cable stop" type, where there is an ear cast on for the cable adjuster.
Then, how does the cable locate to provide the necessary pull against the Bowden winding on 42-5853 and other brake plates that have not cable stop on them,? There must be something on the right fork leg then?
-
The plate with the cast ear is the 1958/59 7 inch rear brake plate. See first photo.
On the 8 inch plate the pivot/fulcum extends through the plate and becomes the cable stop. Second photo.
The normal cam suites the Triumph shoes - make sure the pivot pads are in place on the shoes before fitting. Triumph pads are slightly narrower than the BSA type.
-
This is the inside view of the 8 inch A10 brake fitted with floating shoes.
-
Extremely kind of you to go to this detail for me. Yes I have noted the fulcrum pins either have a recess for the Bowden with adjuster at the handlebar end, or a screw hole which would have used a threaded adjuster close to the brake.
The whole idea of the "floating" brake is that the fulcrum pin is less dia than the fulcrum pin drilling and so actually "wobbles" in the hole - this sounds dreadful but in actual fact makes the shoes auto-centralise each time they are applied? Have I got it right?
Have an excellent Xmas!
-
Peter the fulcrum pin does not wobble in the hole, the larger diameter allows you to centralise the shoes. With the fulcrum nut loose, apply the brake and it will centralise the shoes. Hold brake on and tighten the nut. Job done. Shoes centraised. The point of floating shoes is that they slide very slightly on application of the brake.
Some competition model BSA B44 used a floating fulcrum as did some Royal Enfield.
-
This is the inside view of the 8 inch A10 brake fitted with floating shoes.
A question if I may: My Jan 1960 GF 8" FWH hasn't been fitted with floating shoes (see pic) but I do have a new 'bonded' set of floating ones that I bought some time ago to try. Is it worthwhile?
-
Worth a try but you would need to give the new ones time to bed in before you would know if there was any improvement.
Sometimes new shoes fitted with anonymous linings produce disappointing results.
-
Worth a try but you would need to give the new ones time to bed in before you would know if there was any improvement.
Sometimes new shoes fitted with anonymous linings produce disappointing results.
Thanks for your reply, I know BSA put out a Service Sheet in 1961 about changing to floating shoes so I just wondered if that design was such a big improvement over the previous. The floating shoes I have are SOK so likely to be worse than what I have now even when bedded in. Everybody seems to sell them - and all at different prices *conf* . There doesn't seem to be anywhere where we know we will get a decent set of brake shoes *sad2* .
-
There actually is somewhere to get an excellent set of brake shoes, they even will make them oversize to your drum vernier measurement after skimming!
Try Saftek co.uk
-
http://www.saftek.co.uk