It's not often that people think about the brakes when they plan to modify a motorcycle. The Italian outfit Brembo has top-end brakes and Brembo is probably the first name that springs to mind.
Brembo Radial Monobloc calipers are the standard choice for all the high-end motorcycle brands.
Basically, the Brembo Radial Monobloc are forged in one piece and feature four 24mm pistons. They can cope with discs up to 5.5mm thick and they come with Brembo brake pads. They come in two fittings – 108mm for most Japanese motorcycles and 100 for 'European' motorcycles. It's best to make sure you select the correct one. And, for those who want 'more', there are also lightweight Brembo Calipers CNC machined from solid billet, the finish of which is astonishing.
A forged Brembo RCS master cylinder if you fancy an upgrade or something nice for your motorcycle. You can adjust the ratio – rather than just the span – to 18 or 16 in order to properly adjust the pressure on the brake rotors for a given amount of 'squeeze' on the lever.
You can use the Brembo RCS Master Cylinder legally for your street legal motorcycle without much problems as the Brembo RCS comes with brake light switch. It is designed as a race part, so will fit most motorcycles with a bit of fiddling.