For those who have twin-disc front ends.

[MacMcMacmac]

I offered up the fzr1000 discs with the spacers I machined and they went on beautifully, however, as other have no doubt discovered, the left disc bolt heads smack into the speedo drive. Are a set of button head Allen bolts all that are necessary to remedy this? Also, I have a set of second gen SV 650 calipers which will finish off the brake upgrade, and I'm wondering what is the best way to set them up. Do I retract the pistons and mount the calipers so the non-piston side is closest to the disc, or do I put the piston-side pad closest to the disc? Or is it best to bring the pads tight to the disc and lay out the caliper adapter based on a centralized caliper? I can't wait to see how these work out. I got them with braided lines attached, so I might just trim them to lenght and attach new banjo ends.

 

[XSLeo]

I have dual disc setups on both my 75 and 81. I had no issues with bolt heads hitting anything. I used all Yamaha parts. No need for spacers that way. Button head Allens should work, the heads are thinner. If that's not enough you can try countersinking the holes and using, I can't think of the word but bolts that have a tapered heads that fit countersunk holes.
The 75 has slotted 5 mm thick rotors. I use the stock 14 mm M/C.
The 81 has slotted 7 mm thick rotors. Again a stock 14mm M/C.
I have Mike's braided steel lines. Stock calipers and pads. They work very well.
On your calipers I would set them up centered over the rotor. If you have it set off to one side too much you might get one pad dragging.
Leo

 

[fredintoon]

Hi Mac,
how proud are the fasteners that you tried?
Could you grind the heads down and still have enough head height to get a wrench on?
Or perhaps use countersunk Allen heads?
Or, you have already switched to mini-gauges, how about swapping the speedo drive for an eliminator and going electronic on the speedo?

 

[MacMcMacmac]

They take a small chunk out of the speedo drive with each revolution, so button heads should do the trick. Having to bring the rotors out 10mm with the spacer to make up for the shallow FZR discs brings the heads out as well.