I have an old (2013) scott aspect 620 hardtail that I now use for bikepacking. Recently had the gear hanger snap, when replacing it noticed the rear derailleur is looking pretty bashed, cogs worn. Replaced the cogs/hanger, but next ride out the hanger snapped again on a benign trail with no strike or anything stuck. What I think happened is the chain came off the bottom cog and managed to lodge in between the lower cog and the cage (which shouldn’t be possible?).
With that in mind, time for a new derailleur. A look on shimano’s site shows the only 10-speed parts are for single/double front setups. Will they work with a triple (I’ve no interest in replacing the front).
The other thing that occurred to me is the last 2 hangers were from some online ‘hangers for everything’ replacement site, I wondered whether these are a bit weaker than the original one. The second breakage in particular seems to have had no force applied.