Thunderace rear caliper problem

[Dave48]

Ok, so hopefully this will come up for people who search in the future - I have a new conclusion:


An early R1 caliper has 38mm pistons, the same as the stock FZS600 ones, so probably not much gain. If you could get it to work... BUT no matter what I did (I spent hours making a small bracket and fitting/bleeding it so it was 'perfect') it wouldn't work properly. My guess is that the master cylinder for the rear brake on an R1 is bigger than the FZS600 one as it simply wasn't pumping enough fluid, even after lots of bleeding, to get the pads to grip the disc properly.

So conclusion is: R1 rear calipers have been tried, but they don't work. What is next that people wonder about? XJR1300? :p

So how did you get round the hydraulics issue? Did you change the master cylinder? You mentioned difficulty with flow rate/piston travel.