OK you Bianchi experts, help me out if you can. Have y'all noticed that there are at least two distinct and non-interchangeable classic-era integrated headset styles out there?
I took the headsets out of my early-60s Specialissima and mid-60s Gran Sport, to remind myself of the differences. In a nutshell, the Specialissima is made by Campagnolo, and it's a cup and cone design, while the Gran Sport is more cheaply made (probably not Campy), and a V-groove design like many old Stronglight headsets. (An identical V-shaped groove, both above and below the balls; neither one a cup or a cone. A bit hard to describe but instantly recognizable. See pics, web link below))
When I tried to put the GS headset in the Specialissima (due to my Specialissima headset being badly pitted), the lower head cup pressed in too far, so the crown race rubs on the frame lug before the balls contact the races. I think the Specialissima lug could be ground down until the crown race cleared (about a millimeter), then it would be a workable fit -- but then going back to the right headset later would be very difficult, so I'm not inclined to do it. Possibly the thinner GS lower cup could be shimmed so it doesn't go so deeply into the lug, but the shim would have to be very precisely made, not a trivial project for me with no lathe.
My questions are, what other Bianchi models used this Campy headset like my Specialissima? Did the classic Folgore have a Campy, or a V-groove, or something else entirely? How about the Campione del Mondo, Paris-Roubaix, others?
Any Bianchi owners willing to loosen their headset enough to be able to tell if it is a cup-and-cone design or a V-groove? (You don't have to take it all the way apart to tell). Or if you just want to know if it is Campy-branded, just take the top lock nut and any washers off, and look at the top surface of the screwed race -- it will have the C-in-a-diamond logo stamped in, if it's Campy.
I made a web page with pictures of both headsets, and my observations.
It's at:
http://bulgier.net/
Mark Bulgier
Seattle WA USA