Rear disk brake conversion
The most straightforward way to put a rear disk brake on your bike is to find the rear disk parts from a Euro spec bike. Try eBay France. Parts you'll need: rear wheel (hub, spokes, rotor), caliper, master piston, and brake lever. You'll have to weld a bracket to the frame to mount the master cylinder.
The rear wheel and brakes from an '87-'90 CBR600F "Hurricane" will mount to an NX650 fairly easily. I've found a number of these bikes for less than $500 on Craigslist. You'll need the rear wheel, caliper (with mounting bracket), and master cylinder. Cut the brake stay bracket off the CBR swingarm and weld it to the NX swingarm. Welded a mounting point for the master cylinder to the frame. You will also need to modify the brake pedal, or an XR650L pedal may work instead. The CBR rear wheel is a 17x3.50. The rear brake (CBR600F) is a two pot caliper, which will make the rear brakes work better than the front. This isn't a problem on asphalt, but on dirt it locks up easily.
Pablo83 screwed with this post 07-26-2010 at 08:48 AM