Brake master cylinder ?
 

Does a 900RR have a larger master cylinder piston than our Superhawks? I know that the hawk has a 14MM piston, just wondering if a 900RR will work good with F4i calipers and braided lines. I don't like the lever travel on my bike and would hope this will do the trick.

Thanks
B

The best thing to do is change the whole system. The 929,954,RC51 have the better master and calipers. This way the system is matched up the way it was designed. If you just want to change the master get one from a 929,954,51. I read on a post there might be different size bores betweeen the years so the early bike had 19mm bore. Not sure but you need to check. The master is the quickest way to improve the brakes.

I changed to the RC51 system and have a set of ferodo sinter grip xr pads for stock SH calipers if your interested. Very little use cost $150.00 new.

I believe the RC and 929 had a 19mm dia while the 954's was 17 (or was that 16) mm

The F4i mc is 5/8" (16mm) and the 954 mc is 17mm. The caliper pistons for the F4i are 34 mm and 32 mm and the 954's are 32 mm and 30 mm. The larger the mc the firmer the lever will be with the tradeoff of more effort required at the lever for a given amount of brake system pressure.
I have the F4i mc and calipers (which are externally identical to the 954 calipers) and they work well.
I don't know the mc size for the 900RR, but you can find it in a service manual.

I have a set of 954 calipers (in gold) and my bike came with black ones....I like the black look better. I have a set of black F4i calipers coming in any day now. I have a set of new EBC HH+ pads on the way too (for the F4i,954 calipers). I planned to do lines and the F4i calipers with pads and wanted to do 900RR (for the same lever look) or I will do a 929,954,RC51 master cylinder. I just don't like the lever travel I have now.....I got spoiled with my TL 1000s brakes. Anyhow thanks for the info....I will keep my eye out for a Mastercylinder (929 or 954).