Check out any of the twenty-eight Rear Wheel components enlisted.
The most reasonably priced component used on the Xr650r 2004 (4) European Direct Sales Rear Wheel is the Nut,hex.,8mm.
Some items from this specific schematic: Stopper,bead, B/brg Rad N/com, Washer,18x32x2, Oil Seal 28x47.2x.