Spongy front brakes.

[turbofb]

I'd really like to know what other people's twin disc bandit brakes are like, and what size master cylinder they have. the only thing I can think of now is that the master cylinder isn't big enough to cope with moving all 8 pistons + the expansion of the rubber hoses.

So as I see it, I could either get braided lines or try a bigger master cylinder... hmm

Im running a 5/8" Nissin master cylinder which actuates a pair of 6 piston calipers through Goodridge Kevlar lines.Its a rock solid pull on the lever,and 1 finger stoppies are quite simple to acheive.....not that I have the cajones to try that often!

If you are running a single disc M/C then its definately not going to cut it,since its made to operate only 2 pistons and you say your now running 8.

[erik]

I figured out what was wrong, well mostly.

I had a look at a mate's R1's callipers and noticed that the pistons didn't visibly move when you pulled the lever, but on my bandit, the pistons were moving about 0.5mm each side, so half the lever travel was used up just getting the pistons and pads to the discs before any pressure was applied to the pads/discs.

Ages ago, I'd assembled the callipers as the manual said, using only brake fluid to lube the pistons and seals.
I pulled them apart again and used rubber grease (special grease that isn't supposed to damage the seals) to lube them when putting them together.
Now they're quite a bit better.

I also tried putting a different set of callipers on it from another B4, I'm not totally sure whether my own callipers assembled with rubber grease are as good as the other callipers. Looking at the pistons in my callipers, it doesn't look like they're moving when the lever is pulled. But I tried feeling the space between the inner side of the calliper and one of the wheel spokes and I think I could feel it moving a tiny bit when the lever was squeezed. I didn't check if the other callipers did that.
Anyway, I've got a trackday on sunday and I'll see how my callipers go, if they aren't good enough, maybe I'll switch back to the spare set. I'm not sure if there actually is a difference between the callipers or not.

But I am sure the rubber grease helped. So don't listen to the manual, use rubber grease when assembling the callipers. That's what I reckon anyway.

[JmuRiz]

Im running a 5/8" Nissin master cylinder which actuates a pair of 6 piston calipers through Goodridge Kevlar lines.Its a rock solid pull on the lever,and 1 finger stoppies are quite simple to acheive.....not that I have the cajones to try that often!

If you are running a single disc M/C then its definately not going to cut it,since its made to operate only 2 pistons and you say your now running 8.

Question, does anyone know if you can fit a 6-piston caliper on the single disk setup.  Something like this:

http://www.hawkworks.net/listerpix/steve_lenac/

Just wondering, that might be an economical way for some of us to increase stopping power.

Thanks,

[gsxr400 racer]

sure if you make a adapter use cardboard as a template