Master Cylinder compatibility

[erkishhorde]

I've been looking through parts for sale for a clutch master cylinder but I realized that I don't know what ones are compatible w/ my old monster. I'd like to switch to radial mc but that's all I know. Not much reasoning behind it other than I'd like to see what the difference is.  So, what MC are compatible with the '95 m900? Does it matter what calipers I have?

[Slide Panda]

Only if you've got something whacky for calipers. As far as MCs - if you've got the stock calipers, then you can easily grab the masters off a Monster until 2004, 1000cc + monster after that. 749/999 748 916 996 998, for sure and probably the hyper M1100 as well

[junior varsity]

Clutch Master... and calipers?


I have currently, or have had Brembo GP radial masters (a billet 16x18 clutch, and a forged 19x18 brake) and SBK radial masters.

The pivot ratio and  piston size of your master and the piston size of the slave (for the clutch) change both the lever effort and distance for disengagement.

The pivot ratio and piston size of your brake master is guided by how firm a lever you want and how many pistons your calipers have. Dual 4+ piston calipers typically get a 19mm or so aftermarket masters. Examples: Brembo GP 19x18, 19x20, Brembo 19 RCS, Accossato 19x18 and 19x20, Discacciati 19x19, ISR has ~16mm and ~18mm for 4 and 6 piston calipers.

Note that not all masters have mirror mounts!  Rizoma makes a clamp that has a mirror mount for SBK/HYM radial brake and clutch masters, so there's a solution.

Note that not all masters have clutch or brake switches for kill or stop light activation! (There are ways around this too - like pressure switch banjos)

The top of the line masters are billet. The top of the line brake masters will be both billet and have remote adjuster. Accossato even has one that has an electronic remote brake lever adjuster!

Your clutch master is whichever one you like. On a SportClassic I ran across recently, they had a Brembo RCS clutch master and a 30mm billet slave. The lightest clutch pull I've felt in a long time. Don't know if he had changed weight of springs on clutch or if there were washers under the caps, which vastly changes the effort required on the clutch lever.

Personal example:
My M900 is a 1999. Came with the axial mount Brembo Goldline master cylinders with remote reservoirs and the 4 piston 2 pad 1 pin goldline calipers (i think is what you would have as well). I upgraded the master cylinders long ago to Brembo GP's (16x18 clutch and 19x18 brake - forged... billet one day!) and needed to change brake lines for proper banjo fitting bend, put on made in hongkong billet clamps that had mirror mounts, and used a pressure switch banjo at the master for stop-light activation.  Recently obtained ISR billet 6-piston monobloc calipers and appropriate brake lines to make it work. Didn't change the 19x18 master - lever feels great, brakes are BIG by any measure for sure.

[erkishhorde]

Thanks for picking up on my confusing way of asking about both  clutch and brake MCs. Thanks for the info. 

[junior varsity]

let me know if you want more info.

i'm trying not to write mini novels as it becomes overwhelming

[junior varsity]

I would encourage you to look at Brembo RCS and ISR master cylinders - they have adjustable ratios so you can "tune" them to your liking. Pretty neat stuff.

Don't think either have mirror mounts from the factory, but i know you can get adapters for the rcs or just do bar ends

[erkishhorde]

I like my napoleons so mirror mounts aren't a problem.

[junior varsity]

The forged 19x18 upgrade (with appropriate line) and good pads and floating rotors was a really good brake upgrade.

[erkishhorde]

I wish I could afford an upgrade. Right now I'm looking for anything to get the bike moving again.  Upgrades once I have a job again.

[junior varsity]

Ooh. Yes. Prioritize for sure.  What is currently not functioning in your hydraulics?

[erkishhorde]

Only the clutch MC is actually kaput right now. It's leaking from the point where the lever pushes the cylinder. Both sides have rust though. No matter how much I flush them, it keeps looking murky with little bits floating in it soon after.

[Duck-Stew]

If they've got 'floaty' white bits in 'em, they're done IMO.  You really can't clean it out (IME).

The axials off this S2R 1000 will bolt on and since they include the brake switch, you won't have to adapt your coffin style brake switch to the clip in later style, just plug the wires in...