Plunger front brake

[Craigy]

Hi guys,
Looking for advice again….bike has been running well. My son rode it for a few miles last week while we were out together and all was well. When I went to move it around the garage I noticed the front brake was a bit soft, so I brought it up on the cable, all seemed ok on the lever but when I tried to move it, it seemed as though I had adjusted it up too much so I backed it off a bit.
As I rolled it down the drive, something seemed to come adrift. Nothing to see so thought maybe a brake shoe spring.
The plate/brake cover also had free play in it.
I’ve had the wheel off and nothing to see there as all looks fine.
My question is, what stops the plate from rotating? It doesn’t have a torque arm and I can’t see any ‘slots’ for anything to lock into.
Ivegot the wheel back on but not done any more to fix it as too late here now.
Cheers guys

[chaterlea25]

Hi Craigy,
The brake plate has a round boss on it, this locates into a lug at the rear of the fork leg.
The whole lot is clamped to the fork by the axle.

John

[limeyrob]

It looks like the boss was not engaged, a "close call".  Follow Service Sheet 212A
https://oldthumpers.wordpress.com/wp-content/uploads/2012/02/212a-front-hub-and-brake-7-inch_a-b-m.pdf

[Craigy]

Cheers Rob and John.
Much appreciated

[Craigy]

Just realised pic is upside down, sorry lads

[CheeserBeezer]

Are you sure you have the correct RHS fork slider? It has a lug cast onto it, just above the spindle, with a small round void to accommodate the 'button' on the brake plate.

[JulianS]

Like this one.

[limeyrob]

Good point, and take your time doing the spindle up as its easy to put force on with the peg not fully lined up.  If you don't have the correct fork leg you may be better off going for the 8" brake.

[Craigy]

Now that I’ve got some proper daylight on the job, I can see the cast lug.
Couldn’t see a thing last night either the shadows being cast

[Swarfcut]

 In earlier posts this machine is a 1952 Model. By my reckoning this would have left the factory with the 8" Single sided hub, along with the conventional torque arm back to the mudguard support lug on the slider.

 Looks to have been restored, but not to original spec. for the model year.

 Swarfy.

[Rex]

Later A7's seem to have come with the 7" for the longest, but I suspect it's the old "use up what's in the stores etc etc" scenario.
That said, as I can personally attest, changing to the 8" S/S is a good idea, particularly for your cardiac health.

[limeyrob]

Yes the Roy Bacon book suggest that the 7" brake lingered on on for the A7.  Probably until there were none left.  I had one on a B31, terrible, swapped it for the 8".  You can use the same fork leg and even leave the lug on  so its fully reversible.  The brake anchor brake is already there are its used for the mudguard.