This is a little embarrassing, but had to share it with you guys, even though it displays a gross lack of maintenance on my part! The teeth on my countershaft sprocket have had the tell-tale bend in them for a while, and I'd even bought a new sprocket months ago to replace it. However, after repeated attempts with my low-pressure compressor and a rattle gun, I haven't been able to get the old one off. So I put it off and put it off....and it didn't seem to be getting too much worse.... And then I went for a ride yesterday and she finally let go, seen here next to the brand new one. The chain didn't actually slip until about half revs, unless you were either at full compression or extension with the suspension, which is when the chain's loosest. Needless to say this made life in the whoops a bit interesting given the massive movement in the swingarm!!!