Aftermarket Brake/Clutch Master Cylinder

[Psychopath]

Hi all!

I'm currently re-assembling my R11S race bike for my 3rd race season. For the last two seasons I have been using the stock brake and clutch master cylinder "bricks" which haven't given me much trouble.

Brake Master Cylinder

Two notes:
-The master cylinder housing is cracked and in need of replacement.
-With fresh fluid and seals I've been using the full range of the lever to slow the bike for corners.

I am considering switching to an aftermarket brake master cylinder with a larger diameter piston. Most likely 17mm.

Thoughts?
I know the piston diameter but what is the stock length/stroke/whatever?

Clutch Master Cylinder

What is the stock bore/stroke of this? I want to match it with an aftermarket unit.
Also do you think replacing the stiff plastic tube with a steel braided brake line (master>slave) would create any problems?

Thank you for your advice!

[BadToTheBown]

If memory serves me the earlier ones (my 1999) are 34/32mm but I'd check me on this. These are the ones that fit the the 305mm rotors and the calipers say Bremdo on the outboard side. I'm not sure what the size of the pistons are for 320mm rotors (later model, EVO?). I believe the master cylinder for the earliers ones (my 1999 and 2001 bikes) is 20mm but check me on that too. I'd consider either the Brembo or Accossato master cylinder in 19mm dia with 18mm stroke (19x18). I know the MC is smaller but I think it will offer you a little more feel if you go this way and go radial. Obviously you'll have to change out your controls. Another option is Migura. I'll know how to do this after the winter as I'm planning to do it on my project bike. I'm looking to use the controls and grips off the F800GT. Some rewiring and solder will be necessary and I do not know how the radial will clear these controls yet. I have an R1200S clutch master cylinder to go on the other side.

IF you have the later calipers (Tokico? with BMW on the outboard side), then this is probably going the wrong way on feel. I put the R1200S calipers on my R1150S Project Bike and it feels like too much, although they work fine. Very little lever pull and I have full on brakes. A little research says R1200S have a 16mm MC and here I have a 20mm with it. So, I'm going smaller in hopes of picking up a better ratio for feel.