A while back I got an aftermarket 16mm radial master cylinder for next to nothing (about $40 with shipping) and threw it on. See the thread here: https://www.wristtwisters.com/forums/...ers-25724.html
. While it did work fairly well the overall ratio was too high, 173:1 compared to the 120:1 stock, consequently it took a lot of lever movement to engage and always felt spongy: a common problem with too high a ratio. The braking effort was significantly reduced, but it just never felt right. Then it started to leak out of the secondary seal so I trashed it and reinstalled the stocker.
Well, I was not satisfied with the way things turned out and was determined to give it another go. Lo and behold I found an '07 CBR1000 master on Ebay and got it for $57! It has an 11/16" (17.46mm) bore and an interaxis ratio of 118 / 18, shaking out to an overall ratio of 135:1: much better than my previous try! After completely tearing it down and inspecting all the internal components -- they showed no wear at all and the bore looks like it had never been used -- I swapped it in. All that was left was to machine a new reservoir feed fitting from a scrap of 7075 T6 I had lying around to replace the broken plastic piece, knock out a quick outlet manifold for my AN fittings, replace the inop brake light switch, and mount it up. It took ~ 3 minutes and 15cc's of fluid to get a rock hard lever (It's good being an expert!) and it was ready to go for a ride.
In a word: very nice! The lever feels slightly more firm than the stocker, partly due to shimming the piston for better proximity to the compensating port, and it's practically one finger regardless of how badly you may need to stop. Even howled the front tire with one finger: a first for this system.
Another thing -- notice the lever. Yup, it's a CRG shorty which probably costs more than I paid for the whole shebang. How could I not get it?
That's it for now. I'm going for another ride.