Mod to improve 7" front brake.

[Derek996]

Thanks Neil. I can see all the pictures without joining the forum and will cut and paste all the pictures and relevant text into a document of my own for reference. I'll now start looking for a used 7" brake to work on.

Suggest you crack on with it (based on my exerience this am) met two huge tractors in lane this am. Car in front slowed and stopped.  I slowed and did not stop!!

I know the feeling. 3 or 4 years ago on a single track road I came round a corner with a high hedge on my side  obscuring any view round the corner. One third the way round I met a huge 4x4 coming towards taking up the whole road. Luckily I was on my Ducati Supersport with ABS. I came to a halt with about 2 feet to spare and the back wheel in the air. If I'd been on the ZB32 I'd have been mince!
Yes I'll look into that brake improvement but it's not likely to happen until the winter. I'll just have to be extra careful in the meantime.

[neil1964]

Thanks Neil. I can see all the pictures without joining the forum and will cut and paste all the pictures and relevant text into a document of my own for reference. I'll now start looking for a used 7" brake to work on.

Suggest you crack on with it (based on my exerience this am) met two huge tractors in lane this am. Car in front slowed and stopped.  I slowed and did not stop!!

I know the feeling. 3 or 4 years ago on a single track road I came round a corner with a high hedge on my side  obscuring any view round the corner. One third the way round I met a huge 4x4 coming towards taking up the whole road. Luckily I was on my Ducati Supersport with ABS. I came to a halt with about 2 feet to spare and the back wheel in the air. If I'd been on the ZB32 I'd have been mince!
Yes I'll look into that brake improvement but it's not likely to happen until the winter. I'll just have to be extra careful in the meantime.

Yes, though I was too. I wonder if partly moving from one very similar bike (the ABSAF 600) with razor sharp brake to the scrambler with poor 7" I clearly was not being as careful as I should have.
New stanchions, wheel rim, mudguard and headlamp shell will be needed.  Heaven knows how much the electric Beemer will cost - afraid that will be down to insurance.

[EDDIE SIMPSON]

the 7 "brake with the threaded fork is a good stopper. also used for the b40 /44. good quality linings needed.
the better b40 brake plate can be used on the earlier b31/ plunger if the bearing spacer behind the brake plate is swopped also. the later brake plate is stronger but the b40 wheel rim offset is different so no wheel swop.
another mod i use is building up the brake cam profile with arc weld so there is more early bite.
the brake squeels and snatches  at first on a ride before bedding in nicely after the first corner.
surprising how good they can be with fettling . however glazing is your enemy.

[limeyrob]

Re gazing, yes its really important to use drum brakes as hard as you can from the off with new linings.  I often hear of people "bending the shoes in gently" and know they will be doing a lot of filing to get back to the fresh material.

[neil1964]

the 7 "brake with the threaded fork is a good stopper. also used for the b40 /44. good quality linings needed.
the better b40 brake plate can be used on the earlier b31/ plunger if the bearing spacer behind the brake plate is swopped also. the later brake plate is stronger but the b40 wheel rim offset is different so no wheel swop.
another mod i use is building up the brake cam profile with arc weld so there is more early bite.
the brake squeels and snatches  at first on a ride before bedding in nicely after the first corner.
surprising how good they can be with fettling . however glazing is your enemy.

The brake is arc'd both ways and I used genuine Ferodo linings (getting rare now).  MOT tester said that they passed ok (I watched has he did the test as it was post restoration and I was worried that this was the weakest part of the machine.  Important to note new cable and correct 90 actuator when fully applied etc. As I said a slower and not a stopper (at least on a healthy GS scrambler engine!)

[V500]

Re gazing, yes its really important to use drum brakes as hard as you can from the off with new linings.  I often hear of people "bending the shoes in gently" and know they will be doing a lot of filing to get back to the fresh material.

Similar to pistons, then...

[Janacek]

Reading Janacek's post about the poor front brake on his bike reminded me that there is a mod to improve the 7" front brake  fitted to the older machines but I can't find any details about this anywhere. Does anyone on here know what the mod is?
[/quote

Just had my brakes re-lined (7 inch Ariel type hubs) by Villiers Services.
The drill is to measure the ID of your brake drum,and the diameter of the brake shoes on the brake plate just the metal and not the linings,and Villiers will fit linings to suit.
I asked for softer road use linings and the brakes are now very good.

[Derek996]

Just had my brakes re-lined (7 inch Ariel type hubs) by Villiers Services.
The drill is to measure the ID of your brake drum,and the diameter of the brake shoes on the brake plate just the metal and not the linings,and Villiers will fit linings to suit.
I asked for softer road use linings and the brakes are now very good.

Thanks for that tip. It will also have to wait until the winter as I'm using the bike just now and intend to until late autumn.

[V500]

And only £25 including return postage.

[neil1964]

And only £25 including return postage.

Yes they did the shoes on my Dow TLS front brake. Very reasonable and very speedy. Would certainly recommend them for relining. I've got whatever Phil Pearson put in his TLS version of Dow front brake.
I've had good results with the genuine Ferodo shoes on rear brakes, but the front one, despite my best efforts, was found wanting (the engine in this bike is long rod clubman's spec so 90 mph is easy on the shortish gearing 18/43, 19/42. I'll put it back together now and prioritise the TLS mod for the 7".

[limeyrob]

Interesting about the Ferodo linings.  I drive a 1970 Series Land Rover on drums and there's a lot of discussion on brake friction and linings.  The original Ferodo come out very well, most every aftermarket are terrible (too hard) but the latest polymer linings are very good.  I now have high friction linings and my 2 1/4 ton truck can lock its wheels.  The problem with the Ferodo shoes is that they are almost impossible to get hold of.
From my experience a modern high friction lining will be around 2x better than "standard" hard linings and rather more than that on a TLS as the higher friction is multiplied by the self-servo effect of the TLS so the lever pull is reduced.

[neil1964]

Interesting about the Ferodo linings.  I drive a 1970 Series Land Rover on drums and there's a lot of discussion on brake friction and linings.  The original Ferodo come out very well, most every aftermarket are terrible (too hard) but the latest polymer linings are very good.  I now have high friction linings and my 2 1/4 ton truck can lock its wheels.  The problem with the Ferodo shoes is that they are almost impossible to get hold of.
From my experience a modern high friction lining will be around 2x better than "standard" hard linings and rather more than that on a TLS as the higher friction is multiplied by the self-servo effect of the TLS so the lever pull is reduced.

Interesting. I fitted the TI console front disc kits to my SWB S3 about 25 years ago.  They use Merc van callipers and work very well (still do).  I had to replace discs and used BMW 3 series discs with adapter plates as the originals got worn after 40k miles. Yep the Ferodo lined shoes are now getting thin on the ground.

[ducati2242]

This is how I improved mine

[neil1964]

This is how I improved mine

Yep, I've got two like that both of the 8" single sided finned drum type. Excellent brake, the Pearson one fitted to the ABSAF 600 has HD stainless steel levers, rod and torque stay. I've put an original 60's Taylor-Dow one on the 500 Clubman. This has aluminium levers and rod and it has standard torque stay. 
The scrambler is the 7" single sided type.  This has 21" rim and dual purpose tyres. I'd like to keep that but with greater efficiency that TLS brings. Front end rebuild will start when new seal holders arrive.

[limeyrob]

A question / thought.  This bike is for some off-road use?  If so you don't want a brake that's too fierce which TLS can be.  Could you get enough improvement with modern high friction linings and cutting back the lining on the trailing shoe?  I don't know but it may be worth a try.