Rizzla11

I founds some sizes on the web: FRONT WHEELS:Model Wheel Size Axle Size Disc Outside Diameter1985-86 750 18x2.5" 15mm 11.8" (300mm)1986 1100 18x2.75" 15mm 12.2" (310mm)1987 750 18x2.5" 17mm 11.8" (300mm)1987 1100 18x2.75" 17mm 12.2" (310mm)1988 1100 18x2.75" (3 spoke type) 20mm 12.2" (310mm)1988-89 750 17x3.5" 20mm 12.2" (310mm)1989-90 1100 17x3.5" 20mm 12.2" (310mm)1990-91 750 (U.S. '92 same) 17x3.5" 20mm 12.2" (310mm)

I'll take some pictures. The discs clear the callipers ok, although they are fairly tight. Do you know the diameter of the 86 discs versus the 92?

Had another look today at the master cylinder and can see fluid returning to the reservoir as expected. Also bled the system again which gave a better response at the lever. I ended up taking approx 0.2mm brake material of each pad to allow the pistons to compress and recess correctly. I fairly sure the issue is later wheels with later thicker discs. I took out for a run today and not seeing any signs of brake binding. I think the limited throw in the pistons with wider discs isn't allowing the square seal or return to work correctly. I think I'll have to investigate running the original 86 discs on the later wheels to avoid this issue in future.

No anti-squeal shims install, I just use a small amount of red grease or copper slip on the back plate.

Hi all, I have a 1986 GSXR750 running what I believe is a 1992 front wheel and discs. I've had these wheels on here for a while and have always had problems getting the brakes setup correctly. I'm running standard callipers with 1 mm offset spacer between the calliper and fork leg to centre them, however getting them to operate without binding has been a bit of a nightmare. I've checked the spacing across the front axle which is correct for the setup I'm running (standard 1986 speedo drive with a spacer to align) and a correct spacer on the non-speedo side. I've also rebuilt the callipers with new pistons and seals, cleaned everything before setting up and bleeding the system again. The master cylinder is working correctly and don't believe I have an issue there. One possible problem could be the original callipers from the 1986 model were design to operate with a 4.5mm width disc, whereas the later models ran a 5mm width disc. The original 1986 callipers also ran a thicker pad at 8.7mm, whereas the later model ran a 8.5mm pads. I'm thinking the square seal in the calliper isn't getting enough piston travel distance to deform correctly and recess the piston. Any thoughts? The discs also look a bit worn so thinking about what to do next, maybe replace like for like discs and run the later callipers with an adapter? Cheers, Al