Had the shoes relined and found the braking very poor.Rode around a few times thinking that the new linings would improve and bed in with use,but they showed no signs of improvement.
Took the wheels off to inspect the linings,and found that the front only showed signs of wear on a narrow strip in the middle.The rear showed wear on the outside of the lining,neither brake lining was fully in contact with the drum.
Do I persevere and hope the linings will wear to be fully in contact with the drum,or are the brake drums knackered?
Thanks, Terry.
For the rear, take a file and keep filing down the high spots. The rear will be ok because there's plenty of leverage on the pedal.
If you have the 7" single sided front brake its beyond useless and not worth putting a lot of effort into. The spokes pull the brake drum out of round and so it has to be machined and having done all this its still useless. Spend you time looking for an A7/A10 8" single sided brake with the ally plate. This is a much better brake, has a stiff cast drum and fits the same spindle if you get the right year. Brake stay fits to the forks with no mods, you don't even have to saw the spigot retainer off. Since the rims are the same size just try to get a whole wheel.
Quote from: limeyrob on 26 Apr, 2026, 18:46 For the rear, take a file and keep filing down the high spots. The rear will be ok because there's plenty of leverage on the pedal.
If you have the 7" single sided front brake its beyond useless and not worth putting a lot of effort into. The spokes pull the brake drum out of round and so it has to be machined and having done all this its still useless. Spend you time looking for an A7/A10 8" single sided brake with the ally plate. This is a much better brake, has a stiff cast drum and fits the same spindle if you get the right year. Brake stay fits to the forks with no mods, you don't even have to saw the spigot retainer off. Since the rims are the same size just try to get a whole wheel.
Thanks,I will do that.The drums are the "full width" Ariel type,front and rear are the same.
My error! I had those an an A10, they can be made to work reasonably well as the hubs are stiff. Just keep filing the high spots and ignore my advice on swapping to the 8" unless all else fails! They only fitted the Aerial hubs for a couple of years but they are are well made and easy to adjust.
And not too good in my experience.
I have a large slow-rotating grindwheel used for sharpening lathe tools etc and I find it makes short work of getting 100% shoe contact.
Two felt tip pen lines drawn on the length of the shoes shows where the shoes aren't contacting.
Quote from: limeyrob on 26 Apr, 2026, 19:14 My error! I had those an an A10, they can be made to work reasonably well as the hubs are stiff. Just keep filing the high spots and ignore my advice on swapping to the 8" unless all else fails! They only fitted the Aerial hubs for a couple of years but they are are well made and easy to adjust.
Filed the high spots off the linings,but no noticeable improvement.
As both brakes feel as though they are connected with elastic,I am beginning to think the poor braking is due to wrong cables being fitted.There is a lot of travel on both the brake pedal and the front brake lever and when adjusted to get a reasonable amount of travel,the brakes bind.Both cables look a few inches too long to me.
The brakes were re-lined by Saftek of Cleckheaton and they advertise that they make up Venhill cables.
I need to do some research to find the correct diameter and length of cable specified for the 1957 B31.
Vale Onslow are selling new old stock rear cables on Ebay for BSA Ariel type hubs.
https://www.ebay.co.uk/itm/185173641557?_skw=bsa+rear+brake+cable&itmmeta=01KR95YNJG9JPVQN43F1P1AK4W&hash=item2b1d358955:g:PmMAAOSw6lZhl8Js&itmprp=enc%3AAQALAAAA8GfYFPkwiK
Some modern linings can take a long time to bed in and some may just be not very good. Did Safetek say what the new lining material is or what its characteristics are? They should be able to tell you both.
Below is a page from a Romac cable catalogue which gives some cable dimensions. It does not define whether "Approx length" is for the inner or the outer, in my opinion it is the outer.
Any front brake cable sold for a particular machine will be for the original handlebar pattern and original type handlebar lever.
Have you tried centralising the back plate.
Slacken off wheel spindle , brake hard on and then relighting spindle..
Might work
My C15 hopeless front brake has been much improved by binning the brand new cable and making a 'new' one up from old components. I think the cheap cables available from most dealers have an enormous amount of spring in the outer cable, so half the effort and movement of the lever is wasted compressing the outer cable. Venhill is the only brand I will buy in future - I just couldn't find any C15 brake cables listed on their site.
Hi,
Get the Venhill cables made. They use a heavier outer and inner. This reduces compression of the outer and stretch of the inner. They also have a liner that reduces friction.
make sure that the cable run is as free as possible with no tight curves.
Don't the Ariel brakes have an adjuster like old cars so that the fulcrum is adjusted to give better contact.
Dave.
The adjusters may be seized, unscrew them and get the tread working nicely and the plungers free. Get the cam pivot moving easily. Its all steel running in the ally casting and can get stiff with corrosion. The adjusters have flats so they lock, they don't need to be stiff.
Quote from: JulianS on 10 May, 2026, 16:04 Vale Onslow are selling new old stock rear cables on Ebay for BSA Ariel type hubs.
https://www.ebay.co.uk/itm/185173641557?_skw=bsa+rear+brake+cable&itmmeta=01KR95YNJG9JPVQN43F1P1AK4W&hash=item2b1d358955:g:PmMAAOSw6lZhl8Js&itmprp=enc%3AAQALAAAA8GfYFPkwiK
Some modern linings can take a long time to bed in and some may just be not very good. Did Safetek say what the new lining material is or what its characteristics are? They should be able to tell you both.
Below is a page from a Romac cable catalogue which gives some cable dimensions. It does not define whether "Approx length" is for the inner or the outer, in my opinion it is the outer.
Any front brake cable sold for a particular machine will be for the original handlebar pattern and original type handlebar lever.
Thanks for the info.Looked up cables on Venhill web site and they make cables for just about every bike known to man except BSA! They will make one special if you send the original,but instead I have ordered the old stock BSA one from Vale On slow.
Quote from: Tigerfeet on 10 May, 2026, 19:03 My C15 hopeless front brake has been much improved by binning the brand new cable and making a 'new' one up from old components. I think the cheap cables available from most dealers have an enormous amount of spring in the outer cable, so half the effort and movement of the lever is wasted compressing the outer cable. Venhill is the only brand I will buy in future - I just couldn't find any C15 brake cables listed on their site.
Just been on Venhill's website and they list cables for a wide range of bikes,but not BSA.
They do a special if you send your old cable,but a bit pricey.I think it said £46+VAT.
Hi,
Venhill do universal cable kits and I think they do ones for classics so any threaded adjusters will be compatible. They will need shortening so use the old one for a pattern and solder on a nipple.
Dave.
Not sure why Venhill don't list any BSA cables or kits?
I've built my own up for my Dow TLS as std ones are too short.
The throttle cable kits have correct fittings but I've bought ss adjusters and springs from Barley corn and specced HD cable and outer from their catalogue for my brakes. Oddly George Prew gets his cables made by Venhill to his spec
JJ Cables of Banbury (Fir Tree Farm, Warmington, Banbury OX17 1JL Phone: 01295 971170) will probably be able to help.
Dave made a very good set for me from samples (including speedo) but I believe he keeps listings too.
Its worth taking time to get the best rear brake cable. It takes a lot more tension and some poor copies have been known to fail. You can stamp pretty hard on that rear brake!
Done everything suggested by you good people,filed high spots of the linings but noticed little difference.
The main problem is both brakes feel connected with elastic and both handlebar lever and rear brake pedal have a load of movement to apply the brakes.The front brake lever comes almost to the handlebar before giving any effective braking and rear brake has about six inches of movement before giving any worthwhile braking.
I have replaced both cables,a genuine old stock rear from Vale Onslow and a good quality front.
Still no difference!
To adjust the brakes to get couple of inches movement on both brake controls they both bind badly enough to make the wheels difficult to turn by hand.Both brakes were relined by Saftek of Cleckheaton with a green softer lining on the front and a standard lining on the back.
The front brake is a bit better than the back,but that's not saying a lot!
The only thing I can think could be wrong,is badly worn brake operating cams.I haven't checked them yet
Could this cause the problem I am having with the brakes?
Unfortunately I don't think worn cams will make much difference. It all rather depends on how they are worn but it is worth looking at the position of the lever to the cam and the setting of the adjuster.
One thing to try, which I do on my Land Rover which also has drum brakes, is to do some repeated very hard stops with as much force as I can from about 40-50 mph. This beds the shoes in before they glaze over.
The mix of green linings on the front and std on the rear is good so you have something to build on.
In my opinion and through experience,get drum skimmed ,have over size lining on shoe then machine shoes while on brake plate to suit the new diameter of drum , choose a lining grade that would suite your riding ,to hard a lining not so good until warm and used hard , softer lining good for normal riding , this is my opinion and no doubt other. May differ ,
Have you tried centralising the brake plate.
It can make a difference.
But also, as everything is new, use the bike and take a look at the linings after 50 miles or so , to see what is actually touching
Have you measured the ID of Brake drum ,and OD of brake shoes on brake plate ,
This type of brake is Far from the best that as and Ariel put out , they can be made acceptable, the rear will allways be spongy ,unless a rod brake conversion is made ,
Roy
Was at my wits end regarding the brakes.Was disapointed that new cables didn't have much effect,but the rear brake is getting better,probably less stretch than the old cable.
The front was awful,the lever coming right back to the handlebar.After a bit of thought I shortened the old outer and inner cable by about an inch.Theoretically this shouldn't have made any difference,as the brake arm has to move the same distance from brakes not binding to on.
The front brake I can now adjust so it's not binding and it comes on after a couple of inches brake lever movement.Perhaps someone cleverer than me can explain why this has improved the brake.
Went for a run this morning and when applying the brakes,I got the distinct impression that the bike was going to stop.
Giving the old girl a handful of throttle I was enjoying the exhaust note but then thought it it seems to be revving rather more than usual.Oh no,the clutch is slipping.
Never rains,but it pours.Spoilt my weekend.
As long as neither brake arm is any more than 90 degrees when its brake is on , ideally about 75 or 80 degrees , then , mechanically it has room for bedding in