Originally Posted by
OrangeJoe
I just received "the Bicycling Guide To Complete Bicycle Maintenance and Repair" so I will grab a slice of pizza, raise my leg above heart level and check the section on derailleur adjustment.
I'm still pretty sure it was operator error.
Operator error won't shift a chain off a properly adjusted drivetrain. (with apologies to bikeforum.ner user operator) Get both derailluers' limits adjusted and the chain should not jump off.