Ok,
I've upgraded my Colnago from 5x2 to 6, 7, and now 9 spd.

When I moved to 9 spd, I just cut the axle down to 126mm, adjusted the spacers, and used an off-center rim. It works nice. I spend a lot of time in the small sprockets on the rear, so I think it may also benefit the chain line. I may cold set it for 130mm... but the 126 is fine for now.

No changes to the front derailleur. I had changed to a 9-spd compatible Ultegra a while ago. I'm still using the original Campy friction downtube shifters, but the 9 spd with Ultegra does require essentially 100% of the range for the right shifter.

I've done a little research on the 9-spd rear derailleurs (I haven't paid a lot of attention to the front).

If you use a Campy cassette, then you should match the shifters and the rear derailleur.
On the other hand, if you use a Shimano cassette, then you should use "new" Campy shift levers, and "old" Campy derailleurs.

The way to recognize the old model of Campy derailleurs is to look for the "B-Screw" where the derailleur connects to the hanger. If the tension adjustment is with the B-Screw on the hanger, then it is the old style.

If the tension adjustment is on the cage, then it is the new style.

Campy Derailleur with B-Screw, old style 8 spd (9 speed is similar, but usually noted on the derailleur).


Campy Derailleur without B-Screw, Cage Adjustment, new style 9 speed.