Here are some pictures of the sprockets and chain. I haven't done a thing other than remove the front sprocket cover. I haven't even cleaned anything. At 22,500 miles, I figured a change was due, but now I'm not sure. No chain links are bound up. I believe the chain color is due to chain wax. I need to check the tension, but I suspect it will be good. The sprocket teeth look very good to me, but having never owned a chain driven bike, I'm a bit ignorant on the situation. I am certain the former owner (ctxdawg) took very good care of this bike and never (well, maybe very rarely) rode it hard. Any input is appreciated. Hopefully the pix turn out OK.