I am seeing a pattern here with rear derailleur issues often causing damages to the frame itself (i.e., der. hanger) and pretty much the entire rear wheel. Has anyone used a
breakaway bolt for your rear derailleur on your steel or titanium frame? A friend told me about it just last week. It allows the derailleur to pop off in case it gets bumped hard sparing your bike from very expensive damages. The trick is to always carry an extra breakaway bolt. You can buy it from EBay in the U.K. or through their U.S. distributor: MTBTandems.com