My apologies but i couldn't figure out how to post photos on my computer so I'm starting a new thread on this with photos through tapatalk.
Just to recap - I discovered my rear derailleur was throwing my chain off the pulley. It's ground down the lower pulley teeth and chewed a groove in the cage. The derailleur was new with a group from February 2012. It was on my 2010 supersix for 5 months then on my Evo for 4 months. Both frames, it turns out, have loose der hangers. This seems too unlikely a coincidence and I think it must be the derailleur.
I'm going to ask sram to warranty it but would still really appreciate input.
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