Thanks guys, I sat on the design of the Virago for two years before I jumped in and knocked it out. Was prompted by another forum where a guy was redesigning new front ends. Figured if he was crazy enough so was I. Go for it Lev! You're at least as crazy as me!
So as of late, IT RUNS! And holy shmokes it's loud. Nothing is so encouraging in a build as when you get that first roar.
So time to make sure it will stop when I decide to take it out on the street up to 'ludicrous speed'. I plumbed the FZR master cylinder with FZR stock lines down to the XS and SR500 calipers. Everything bolted up right and proper with line slack at full suspension extension. Began bleeding the system. Took a while to get the juice flowing good. And MOTHEREFFINGSONOFABITCH WHY GOD WHY?!?!??!
See, I had used the FZR sized crush washers in the system all the way down. Well the very last ones that make contact with the calipers needed to be larger, thicker XS ones. I had some in a little plastic drawer out back…while the system decided to hemorrhage DOT3/4 all over the (beautifully painted) calipers which in a rush I didn't tighten the bleeder nipples down tight enough before I ran out the door for said thicker crush washers. When I got back, I hastily swapped out the washers, totally enjoying how brake fluid turns nitrile gloves into slippery uselessness and how brake fluid easily removes 'caliper' paint almost -almost as effectively as brake cleaner spray.
So after my blood pressure subsided. -It really helps to just laugh at the situation as opposed to venting your spleen at the world and god and Yamaha or anything but yourself - I was able to get some nice line pressure. I did reference the recommended master cylinder to caliper ratios,
http://www.vintagebrake.com/mastercylinder.htm and was curious about how two sliding single-piston calipers would compare to two opposed four-piston calipers. The FZR master cylinder is a 5/8 bore which if I remember correctly is the same bore as the original XS master. Anyhoo long story short it's a bit spongy initially, which may be attributable to the old FZR lines along with the different action of the calipers. I could switch to braided steel lines to remove some sponginess but will ride it as is for now. I am thinking the initial softness may be helpful in feel as I have upsized the brake rotor from stock and then doubled it on that skinny front tire. Too much light switch brake power may create bad mojo…
Fork springs definitely need more stiffness… I had this in the back of my head for a while as looking at my SR500 I thought, "Oh hey that's such a light motor. Look at that XS, there's two of everything." Probably 50% heavier overall. Am thinking about some 35mm Harley sportster Showa springs. Fairly cheap and rated for a much heavier bike. That and when you install cartridge emulators Racetech recommends you to run stiffer springs.
Heading out to see my wife today in Cali so will return in a few weeks (with my camera) for more updates!