Well, all, little by little I'm building the functionality of my 919. Recently did the brake lines with the help of Mike (LDH) at Dan Kyle. Went with LDH's advice and am now running the Spiegler braided stainless steel. Opted for black and gold since my bike is matte black with gold DID ZVm chain, gold rotor interior, etc.
I'd love to tell you all that these are the best performing brake lines I've ever ridden, but I've only done one track day and it was the No Brakes Exercise for the first 4 of 5 sessions! I can say, however, that you are on/off the brakes quite a bit in South Florida commuter traffic and these seem to keep me right where I want to be, nice and tight.
I also love the look, including the obligatory Mach Moto holder.
And of course, my novice bike mechanic ass had to screw the pooch on the install. If you go this route, all of the banjo bolts and the OEM rear lines have bump stops to keep the brake line from rotating while you are torquing down the banjo bolts. The banjo bolt under the rear master cylinder does NOT have a stop. It will whip right around and can look pretty bad; be prepared to keep the line in place as you tighten. Same with the double banjo bolt at the front master cylinder.
I also learned the hard way about different fastener materials. Spiegler tells you explicitly
not to tighten the aluminum double banjo bolt beyond 14 ft/lbs. Of course, I went with OEM steel crush washers instead of the aluminum (torque to 25 as per the manual) ones from Spiegler and then had to guess between the two possible torques.
I guessed the seal at the washer took precedence over the strength of the bolt. This was the WRONG decision.
"Hi Mike, it's Jon again. My track day is Friday, can you overnight another double banjo bolt?"
And, of course, as LDH always does, he came through fantastic.
All other things equal, maybe go with the aluminum crush washers with the Spiegler-supplied double banjo bolt at the front master cylinder, and then ss washers where you re-use the OEM bolts at rear master cylinder and calipers.
All in all, another joyous addition to the 919. Mike at Dan Kyle as always provides service/support that is first class--not to mention I learn a great deal during the explanations.
I'm into my second year and am building for control first. I've got the PCIII, renthals, spiegler ss brake lines (and Mach Moto holder!)...
rear sets next before my next track day (tentatively in Feb)?