I haven't bought a chain and sprocket set since '07 but I use to pay $200 to the door for that package. Always change them as a set. If the rear was in that kinda shape the chain and front are shot as well. The hub slides into the rear wheel and connects vis the cush drive on the stocker and yes you have to order a kawi rear sprocket for those wheels from memory. Best of luck. Going on 27K with my original chain and sprockets on my '08 and that rear sprocket looks great.