Hi, yes, apologies, I was trying to answer another member’s question as to why I am
posting two threads related to Campy 12 mech.

I’ll switch to my other thread to answer the questions about my ‘448’ bike (a 61cm 700x32c Jitensha Studio Ebisu sportif with integrated fenders).

The 650b (38mm tire size) ‘420’ bike, that this thread started with, is my wife’s Chapman Cycles bike. We’ve taken it to several pro shops here in NYC and so far haven’t had luck with getting the shifting to be completely zeroed in. It works of course, it’s just not as Campy ‘perfect’ as we think it can be (her other bike is a Chris Bishop 52cm 700c road bike with Campy SR/R 11 50/34 11-29 and she says, as a comparison, this is perfection - though adding this is more about the RD, 12’s FD shifts more smoothly compared to 11).

Could I ask, could this relate to running a 34t low sprocket cassette? Would it potentially shift more crisply with a 29t or 32t cassette?

Thanks!