I had a 500KQ in last week with a badly slipping clutch. Checked the belt fist of course but it was OK. So onwards, with belt pulleys and box removed you can get at the clutch cover. Sure enough, the shoes were worn down to the metal. Never had this on a 500 before, 400KQs are a bit prone to worn centrifugals, but not 500s. As with 400s, Suzuki won't sell the shoes, you have to buy the unit at £240. A while ago someone told me that Honda shoes fit Suzukis. So I bought some cheapo non genuine Honda 300 shoes for a 400KQ to try the theory, and they didn't fit, so they have been in stock since. Checked them against the 500 shoes and they are exactly the same, except the pivot hole is 8mm in the Hondas and 9mm with big countersinks in the Suzuki shoes. Drilled and countersunk them to suit, fitted them and they work fine. Important for alignment that the drill doesn't wander though. Not a lot of "meat" on the new shoes, but I seem to remember the genuine 400 shoes didn't either. We will just have to see how long they last.