The 9- and 10- speed options seem to be not that hard to find, at least second-hand. I mean, 9-speed groupsets have been introduced over 20 years ago, they already look pretty classic comparing to the current aero carbon contraptions. 11-speed, on the other hand...
I have picked up silver Potenza derailleurs and shifters for a classic-look-inspired steel randonnee bike, and I'm stuck on choosing a crankset. I didn't get the Potenza one, 1) because the 4-bolt pattern is ugly, 2) because the full gruppo (or, fwiw, the crankset itself) is nowhere to be found in stock (while the black Potenza parts are widely available with discounts, had to shop around for silver ones). While Athena 2x11 crankset theoretically exists in alloy, finding one that checks all the boxes - UT, compact, 170 mm - seems impossible.
On the other hand, there are plenty of NOS or used 10-speed 5-bolt alloy Campy cranks around. What could go wrong if I pic one and swap the chainrings for 11-speed compatible, if I find them with correct BCD (I think Stronglight and TA make some)?
P.S. is there any difference in terms of finish between the current silver Centaur and Potenza? In the catalog pictures they look identical, but in a single real-life photo of the silver Centaur I found it looked duller than the Potenza version.
The more I look at it, the more I like it ok I am with the 4-bolt pattern. It's no Record, but far not as bad as the asymmetric Shimano. Surprisingly, it also seems to be one of the least expensive 11-speed compatible silver crankset at about half of the TA Carmina price.