Technical FAQ: Campy Chorus 9-speed derailleur with 10-speed drivetrain
Can I use a Campy 9-speed rear derailleur with a 10-speed drivetrain?
Dear Lennard,
Can I use a Chorus 9-speed rear derailleur with 10-speed cogs, chain & Ergo shifters?
-Mark
Dear Mark,
Yes, as long as the wider jockey wheel cage does not contact your spokes.
-Lennard