NOTE: Found this on eBay. The words are the owner's:

The front wheel and brakes are off a 1992 Suzuki GSXR 750;
it is a 3.50 X 17 in. rim with a 120\70X17 tire. CNC caliper
brackets were made for the conversion. Tremendous improvement
to braking and handling!!! The forks have Racetech Goldvalves
in them to help with the front-end dive especially with the
more powerful brakes.