I installed the xr650r sprocket backwards on the 600 and it fit easily with no problem installing the retaining clip. It destroyed an almost new chain in one ride. I know that the sprocket sits 4mm farther from the case and I'm not sure this is the reason but periodically, the chain would go into a harmonic side to side motion to where it would slap the side of the frame. It shattered the chain in maybe 20 places or so and I feel lucky to get home without destroying things. I was running my chain a little loose (on purpose) but is this 4mm offset enough to cause the chain to "snatch" coming off the rear sprocket? I am reluctant to go back to the xr600r counter sprocket but may have to. Any thoughts or others experience this when using the xr650r sprocket? Thank you for any ideas.