Rear Cush Hub & Wheel
OK--got the hot scoop on the rear wheel: get the LC4 wheel for an '02 thru '05. Get the matching backing plate. The part number ends in 144. The other two plates that end in 044 and 344 have the support bearing in the wrong location for our RFS needs.
Assemble with lots of silicon or soap on the rubbers. Put the tire (or rim) on a couple of 2x4 hunks of wood to protect the brake rotor. Then get on the sprocket and bounce up and down until the hub seats in the wheel. You will hear an audible "splork" as it goes together. It will then fit in the RFS swing arm with ease. It will not until you jump on it. This is the secret KTM tool to mounting this wheel.
I have had great luck with the trackmaster chains. They last and are fairly inexpensive. I have my 525 geared 15/52 for all around riding. When I do technical off road I can put on a 14 and just flip the rear axle blocks to pull the wheel back and I am good to go.