any one know if there is a disc like a std sierra one but a bit smaller in diameter?

Think Westfield use an escort mk3 front disc...although iirc they machine a whisker off the Sierra hub to allow the disc to fit.

Al.

I can confirm Westfield do however they no longer machine the disks I think... Hispec who make the rear callipers have modified them to give the clearance...

Dave B

[Edited on 26/2/14 by Dave Bailey]

number crunching tells me if i use my sierra calipers with std sierra discs im pritty close to an over braked rear end so i either need to reduce my rear caliper piston size, rear disc dia or fit bigger brakes on the front?

idealy a smaller disc very simular to the sierra one is what i need.

[Edited on 26/2/14 by baz-R]

Can you not just fit a brake proportioning valve ? I used an adjustable one from a fiat uno, think my rear discs are virtually dialled out.

Escort discs are 240mm btw, so not vastly smaller than Sierra.

[Edited on 26/2/14 by Wadders]

A pressure regulator valve is the way to go loads to chose from, the Fiat valve is as cheap as chips and you could make it adjustable after you get it on the road.
You could also look at the Vauxhall Corsa and Rover 25 or 45 valves.

Hi Baz
With the HiSpec brakes you can order the diameter of the pistons, I went for the smallest as I felt like you that the standard size would over brake the rear.
John