I added two teeth to my sprocket and have noticed that the rubber chain guide block on the swingarm just in front of the sprocket is worn through near the back. I don't think the chain is actually rubbing on the aluminum guard and I'm not sure what the rubber looked like before the sprocket was changed, but since there is only 9 hrs. on the bike with the new sprocket, the block might have been worn before the change. With this sprocket, there isn't really any room to put a new block in there and the guide is not adjustable for angle. What do people do? Buy an aftermarket guide that is adjustable?