11mm Master Cylinder on single disc

Heres some pics of a Nissin 11mm M/C I found in my parts boxes. I put it on my 1980 KZ550a with the stock single disc and single piston brake caliper. The M/C is from a Honda dirtbike IIRC, not sure which one, most likely a late '80 XR. It had the same size/thread banjo and a mirror mount. I was able to 'machine' my KZ lever to fit. It works well, way better than the stock 14mm unit. It has a slightly softer feel at the lever than you would expect from a braided steel line, it feels similar to a fresh stock rubber line. A 12mm M/C may provide a better balance between feel/power.....but I had this one laying around.

second pic.......

because volume of brake fluid moved by the master cylinder is less than stock (by 25%), you will need that much more lever travel to get the same braking force. The key is not having too much travel so the lever comes all the way back to the grip...

It doesn't get too close to the bar, it just doesn't have that real solid feel that you typically get with SS lines. like I mentioned above, braking is much better than stock and the lever feel is similar to stock, so overall I think that it was a good change. especially since I already had the part and i was able to get it to fit and function well. I now feel like I'm getting the maximum possible performance from the OEM caliper and rotor.

I don't have a brake light switch on there so I may look into getting one of those banjo fittings that has the pressure switch integrated into it.

If I wanted to spend a couple hundred dollars I would order a 12mm Brembo M/Cs like the one on my KTM690SMC, I think that that would be the optimum set-up.

Jeff , thanks for the input. I ordered my SS line and a few other items from Z1 and got the parts the next day !!

Like Jeff, said. You go to smaller diameter, the travel increases to move same volume as before, but the effort required by your hand is less, that's why braking is good, even though the feel is not great.

If you went the other way, bigger diameter, the travel will be less, but the effort higher. Those are the trade offs.