Pinwall Cycle Parts has just parted out a couple GS500F's.
I have personally ordered from them many times. I found them to be perhaps the best and most honest bike breaker on ebay.
http://stores.ebay.com/PinWall-Cycle-Parts-Inc/_i.html?_nkw=gs500&submit=Search&_sid=12458664
thanks, I know you as eBay guy lol not adidasguy
I've bought quite a few parts from these guys. Very reasonably priced and they almost always have the part your looking for. :thumb: