First, thanks to
Gary in CA for sharing his brake upgrade experience, thanks to
Slybones for sharing his experience through his excellent website of Connie information, and thanks to COGger
zrxmopar (Shaun) for his original 4-pot brake brackets which, based on Slybones' brake upgrade webpage, I’ve probably copied.
My bike is an '04 model. The calipers are 4-pot Suzuki GSXR 750, 2001 to 2003 model, fresh seal kit installed. The rotors are EBC 320mm Contour. The pads are EBC HH. The Galfer brake lines have been on my bike for years with the OEM calipers, not changed for this upgrade.
I started by making a full-size prototype out of Plexiglas sheet to get the locations for the holes and the shape to fit the calipers. It took 2 trials to get the calipers perfectly aligned for the pads to track correctly on the 320mm rotors. The prototype proved that the flat plate centers the caliper perfectly on the rotor when used on the inside face of the caliper lugs. The bracket is tapped for the 4 bolts, the threads in the caliper lugs are drilled out to pass the M8x1.25x16 flange head bolts. No other modification to the calipers at all. The OEM C10 brake bolts are used at the fork leg.
The pics tell the story … the brackets are 3/16” steel plate. Holes were done with a benchtop drill press through the Plexiglas template and hand-tapped. I was not able to get time on a mill as I’d hoped when I started this project, so finally I just carved the brackets using abrasive cutoff and grinding disks on a 4.5 in Bosch angle grinder – very easy and quick. A few licks with a file to round the sharp edges and a couple of coats of rattle-can caliper paint on the brackets to finish.
View of the bracket from the wheel-side shows the basic shape
Close-up from the outside; flange head bolts through the calipers are zinc plate, class 10.9
Looks like I'll have to watch that speedo cable to ensure it doesn't hang on the corner of the caliper