I'm no grizzled veteran, but I was surprised at what happened to my bike today. I was riding home from work on my '99 Bianchi Volpe (a "cross-tourer", B. calls it), when a plastic bag got blown onto my chain and pulled into rear cogs and rear derailleur. Before I knew it, the RD was bent, and so was the hanger!
Has anyone else ever bent an RD or hanger this way (as opposed to something more obvious, like crashing)? I've never heard of this.
LBS (San Francisco, USA) says $60 to replace dropout/hanger, plus $38 for a Sora RD. At least I didn't go down (it was close, though).