Originally Posted by
FBinNY
if the chain chronically derails when backpedaling it's an indicator the the lower loop chain angle is different than the upper loop's, which usually means a mis-aligned hanger.
Every time I've had a bent hanger, I couldn't get the shifting to work right (in every gear), which was far more noticeable than the inability to back-pedal. My point is that if everything else works well, I don't see what could really be done to fix this problem. Of course, we're getting off topic because the OP said the chain derails at the front.
people_atease: How many chainrings in front do you have and which one are you in when it derails? Does it generally do this when in the largest (outside) chainring and largest (inside) cogs in back?