I’ve discovered something strange going on with by XR650R. it has variable chain tension….. It behaves like the rear sprocket has a high spot on it. Every 180 degrees the chain gets tighter…. The next 180 It’s loose again. I’ve swapped out both back and front sprockets, one at a time I have a stock set of sprockets as well as a range of rear sprockets everything between 48 and 44 and a 15 for the front… it still does it, no matter what sprocket combo I use. It must be the positioning of the rear sprocket mounting holes… or something I’ve spun the wheel, nothing looks like it’s bent or out of whack. Well nothing I can see with the naked eye…. It’s not drastic, but if the chain is set Just right on the loose 180, it’s too tight with me on the bike…On the tight 180. Before you say anything, go and check yours. I mean really… Jack it up and rotate the rear wheel 1/8th of a turn at a time and check the chain tension. I bet most of you have the same issue. I’ve just marked the high spot on the sprocket and set the chain tension with the rear wheel at the “tight” spot. I think I’ll run It down to Honda and see what they make of it….. it can’t be Good for the CS bearings etc… needless to say, there are no seized links on the chain, it's nice and clean and flexible.