Hello: A very popular improvement to the Yamaha XS650 is the addition of a dual front braking system. The images below show two systems that have worked very well for me, and are not very difficult or expensive to build. I apologize for the poor quality of the pictures. The first shows a system that uses the stock 77-84 right caliper with the addition of a left side caliper and bracket from an XS1100. The rotors are from a Yamaha FZR600. To achieve the correct offset, it is only necessary to have your local machine shop make spacers from 3/8 inch aluminum. One is shown at the bottom of the adaptors picture. 2mm must be machined off the front of the caliper bracket mount bosses, and approximately the same amount from the lower part of the bracket (wheel side) to allow for rotor clearance. It may be necessary to shim the mounting points with thin washers to achieve the correct clearances. The caliper mounting bolts will need to be shortened. This system will also work on all models with cast wheels. The other system is a little more complicated and uses Yamaha (Sumitomo) 4 piston calipers and rotors taken from the 2000 to 2004 R6 or R1 models. This system will only work with the cast wheels. The machine shop made the round spacers from 9/16 inch aluminum, and the caliper brackets from 3/8 inch. I drilled and polished the adaptors to improve their appearance. Now for some words of caution. You should not take on this type of modification unless you have the skills to do it correctly. Get a licensed machinist to do the precision work, or you could end up with brakes that are worse than stock. Have a licensed motorcycle mechanic inspect and approve the work when completed. Use a new or remanufactured master cylinder designed for dual brakes. Rebuild the calipers properly and use new high-performance pads and new brake lines. Use only new parts, or the best used parts that you can find. I always look for parts taken from new bikes that were converted for racing. Use high grade threaded fasteners with plenty of Loctite, and check your brakes thoroughly and often. Best Regards, Brooks Knudsen
