Front master cylinder swap on NON SP bikes

This has been dealt with by several postings on the web, including mine on this forum, easy to fix and I'm very happy I did it...

There's plenty of forum stuff suggesting the RCS 19, the RCS 17 really hit the modulation sweet spot, although 19 would have given 1-2 finger power, just not as much feel...I read all of them before I came across the 821 Moster posting suggesting the 17 instead, I little more Internet digging found a site where Brembo backed up the 17 for our bikes...you need to change up your searches, play with the permutations, it can take hours sometimes...

Here's where I originally found the idea for what i did, took 2 mins to find on the Internet...admittedly I knew better what to put in the search engine...
Brembo RCS 19 - ducati.org forum | the home for ducati owners and enthusiasts

Here's what I did, took a little better than 2 seconds to find on this forum...just had to look for my posts...
http://hyperstrada.com/ducati-hyperstrada/3889-hyperproject-4.html - Post 40

This is one of the upgrades I'm most pleased with so far...enjoy...

All I can say is... it can be a little tricky. The SP comes with an 18mm diam master cylinder. I've ridden all sorts of bikes with anything from 14 to 19. I definitely prefer the smaller diameters because it allows 1 finger braking. Coming from mountain biking, I like to have wheel-locking power with just 1 finger. The only downside is with a small m/c, you are moving so little fluid volume that it exacerbates other issues, like misalignment, air in the system, and brake line expansion.

I should offer that the brake master cylinder sizing is not hit or miss or a recommendation based on just 2 pistons vs. 4 pistons. It is about piston size, to some degree how many of them you have, leverage ratio at the lever, how constant that leverage is, etc.

So, a 17mm master ends up being a good fit for modulation on our piston size for when using a radial master cylinder. Can be a little different with an axial master cylinder, although on paper just looking at cylinder size they would not appear to be the same. One also needs to take into consideration how the leverage to the cylinder is applied. A radial is more rigid feel against the cylinder and move consistent application of the pressure. If you look close at the stroke on an axial cylinder, depending on lever position, I think you'll see it changes a little through out the full stroke. I think this is why I feel they are like a switch, when they're on, they're on. I noticed the same on my mountain bike when I switch from Avid axials to Hayes radials. Better feel and modulation for me. I definitely now prefer radial.

If you just brake and don't ride aggressively, I don't think it matters. IF you're pushing riding hard a lot, I think you'll care. So it's a pretty subjective line if you should change over. Remember, your brakes will work just as good with either axial or radial brakes, what changes is your feel of the brakes and modulation is important to this feel. Bigger master cylinders will give you stronger brakes faster but will feel more "wooden". You will need less fingers if that's what you are after. I like to size to use almost all the stroke to get the most feel/modulation...