On the virgin commute for my newly modified Lemond I blew up the RD. It was 1/2 mile from work. The chain jumped off the big ring (I failed on adjusting the shifter). As I have on other bikes I adjusted the shift and pedaled through. On the other bikes the chain will climb back on the chainring. On the Lemond something went clunk, caught hard, and the RD got torn apart. Fortunately the RD didn't go into the spokes and I wasn't thrown. I paddled the bike like a skateboard most of the way back to work.
The hanger, integrated with the frame, is apparently slightly bent. I've put on a replacement RD but the chain jumps gears erratically on the cassette while shifting. I usually don't have good results trying to fix this type of problem - I guess the LBS will get some business. Too bad this is probably the peak season.