Originally Posted by
JohnDThompson
Campagnolo's Cambio Corsa and Paris Roubaix systems were designed when the popular "knowledge" insisted that frictional losses in the chain running through a derailleur pulley cage were simply unacceptable.
The French and everybody else knew otherwise. It just goes to show that Tullio wasn't always right. Once he did switch to a sprung, chain tension cage, he even continued to offer a single pulley derailleur into the 1970s. Things like this really make me question his so called "genius".