Pedaling up a short hill, not particularly hard, a click and a snap.
Looked down and saw what you see below. Derailleur hanger snapped, cage and pulley broken in two, chain wrapped behind the cassette. Not sure what would have caused this, I haven't adjusted my hi-lo screws, maybe my putting the non-spec cassette was stressing the hanger in some way, or maybe it was just a bad derailleur hanger?
Thankfully happened in the first couple of miles of the daily ride and I was with one other so he went back to get his car. Yesterday I was in the middle of nowhere doing some decent climbing so happy it didn't happen then! Funnily enough I had the Ultegra 6870gs derailleur and sent it back to the vendor yesterday morning, now I need to order it again.
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