Here are 18 Campagnolo workshop videos dating from 2009 and 2010. They share a title slide with blue stripes and are all concerned with transmission components. I did not include the ones dealing with Campagnolo's wheels - pah!
I won't pretend that all these movies are classics from the Golden Age of Silent Cinema. Thrilling, they are not. I also don't fully understand many of the titles - and the video entitled 'Replacement of Super Record 11s Derailleur Pulleys' clearly deals with something completely else. Italy is a different place.
Derailleurs make a, sometimes fleeting, appearance in: