I've been doing a fair bit of reading about people's suspension and brake upgrades in anticipation of doing work on my own bike. Originally I was looking at getting custom-ordered WP shocks (though not with every bell and whistle offered) and WP springs to go with Ricor Intiminators for suspension, to be installed at the same time I do my dual-disc setup because I'll be changing my fork sliders.

However I just scored a set of 13.5" Progressive 440s on eBay because the price was right and they're close enough to what I think I would have wanted with WP's shocks, so now I want to get the ball rolling on the rest of my upgrades a little sooner. I'm not looking for front suspension info in this thread. I want to try making my brakes good without breaking the bank. I'm expecting to do all the work myself.

I've got a few questions on my options that I'll break down into sections:

1.) Brake Lines and M/C:
I think I'll just order the Fatbob (11/16in) or new Lowrider master cylinder to handle the extra caliper. I also have ABS.
a.) Are the brake lines on current Dynas braided stainless steel lines?
if they are, cool; I'll either take a look at the FXDF or FXDL ABS brake junction block, or I might just run an extra line with a double banjo bolt from one caliper to the other.
b.) If not, are there plug and play kits for ABS Dynas or am I looking at piecing it together from individual components (with Galfer parts, etc.)?

2.) 300mm rotors
I want to get nicer brake calipers than the FL unit that comes stock on the Dyna. I slapped a Sportster 48 caliper on my bike and it matches the Dyna fork/rotor combo perfectly. I have pictures. I know that the XR1200 caliper fits to a 48, so I may go that with that setup. If I'm adding an extra disc, I'll want to get nicer (and lighter) rotors than the frisbees that come on the spoked Dyna wheels.
a.) Is there any reason why the XR1200X rotors wouldn't fit? They seem to have the same hub-mounted 5-bolt pattern. [EDIT] the XR1200/X rotors are still 11.5in/290mm like the XL sportsters, so that's out.
b.) Galfer doesn't list wave rotors for XR1200s, 2006+ Dynas or 2008+ Touring bikes (all 300mm, right?), but I found this picture of a modded XR1200 rocking these rotors. Can I find a part number for them? Nope, won't work.
c.) Any other 300mm full-floating rotors that aren't more costly than the $640/pair Galfers?

3.) 310mm rotors
I was also able to borrow a Touring Brembo caliper and fitted it to my forks, confirming what the user Fastharley has said on this forum: They don't fit. The friction pads ride over the outside edges of my stock rotor. I took pictures. It looks like there's only enough gap to fit in rotors that are an extra 10mm in diameter, but the only oversized rotors I could find for Harley wheel hubs are the AXIS 320mm rotors. Too big.
a.) Do 310mm rotors exist for Harleys? Rotor inner diameter looks like 90mm, bolt pattern diameter looks like ~55mm

 

you can either turn down the 320mm rotor or you can use a rotor from a suzuki gsxr. those rotors are 5 bolt and if you get one that is oem it will have the room for you to drill the harley hub pattern to it. The hayabusa rotors are 320mm as well and the gsxrs came with 310mm after 2004 i believe. you can find those on eBay all day for less than $100 a set and even cheaper if you have a good local craigslist. That way for mic ups it would be cheaper. good luck with your brake set up.