1" brake shoes

[Martin Prior]

1" BRAKE SHOES and DRUMS. I've discovered that the 1933 RP that I'm rebuilding (The Thing from the Cesspit) was running with earlier 1" brakes on the front axle. The four shoes are all in good condition. I urgently need a set of four 1 1/4" shoes. Would anyone like to do a straight swap? I also have a pair of decent narrow drums available.

[Dave Mann]

11/4" shoes are getting a bit like hen's teeth, put the 1" on the rear. There that's moved this to the top.

[Dave Wortley]

Just how much worse at stopping are 1” linings? Smaller surface area means greater pressure between drum and lining for the same pedal pressure. Like many A7 people I have plenty 1” linings and shoes so I might try them sometime.

[Chris KC]

For what it's worth, the lining width per se does not affect brake performance.

Increased width may affect wear life (positively) and bedding-in time (negatively); and I can't swear there isn't any impact on the application geometry, though I can't immediately think why there would be; and unless you are doing serious racing I'd question whether fade due to high temperature is an issue - but in isolation, friction has nothing to do with surface area.

Friction force F = mu x R where mu is the friction coefficient of the lining and R is the reaction force.
Reaction force, unlike pressure, is independent of area.

Of course if it's originality of build you are after that's another matter entirely.

[Hedd_Jones]

Dad had the same thought about the 1 inch linings Dave, and thus fitted them to the chummy. I cant tell you how they compare as I've not driven one on 1 1/4 ones!

[Martin Prior]

Very interesting responses.  It hadn't occurred to me that 1" shoes could be safely used in a later car.

I'd prefer to change them to 1 1/4" for the simple reason of standardising the "fleet".  

The linings on these shoes, though still quite thick, haven't seen any action for the best part of seventy years, thirty of which were spent in a cesspit, so probably a good idea to replace them before the car hits the road.  In any case, I have spare 1 1/4" linings on the shelf.

[Chris KC]

That's a good enough reason Martin, but I think you'll find 1" shoes are two a penny and 1.25" a little more elusive, or at least expensive.

I think you'd be very wise to replace 'antique' linings.

[Parazine]

What happened to all the 1 1/4" shoes??
Forty years ago, when I was BA7C spares secretary, we had boxes and boxes of 1 1/4" shoes and a few 1" to top them up. Everybody wanted the steel Girling shoes, which had become super rare.

Someone must have all the 1 1/4" shoes in their garage methinks!

[Hedd_Jones]

Dad weighed a load in for the ali once.

[Ruairidh Dunford]

What happened to all the 1 1/4" shoes??

I continually receive requests for 1 1/4" shoes, which I am unable to supply. I think that people perhaps think they improve braking and therefore look to "upgrade" to them - fitting them to many of the early cars in existence would soon dry up the supply, simply supplying 20 cars worth would use 160!