That change is listed in the Campagnolo Timeline at http://www.velo-retro.com
Actually the barrel adjuster was eliminated as being unecessary. Does it serve a purpose I'm not aware of? I can think of none.
Chuck Schmidt South Pasadena, California
> I just acquired an old Campagnolo Gran Sport rear derailleur that is
> different from others that I have seen. This particular derailleur does not
> have a barrel adjuster on it. And the hole where one would think a barrel
> adjuster should go is not threaded. Obviously the cable housing end sits
> down in this hole.
> I have another old Campagnolo Gran Sport rear derailleur that does have a
> barrel adjuster that is hexagonal in shape that thread goes into the threaded
> My question is: Approximately what year was the GS derailleur without the
> barrel adjuster made?
> The only other visual differences between these two derailleurs are that the
> first one is stamped: PATENT CAMPAGNOLO DA14 A 26 DENTI in standard lettering
> on the rear pivot plate. The surface chrome is also somewhat "cruder"
> looking than the second one. The second GS derailleur (with hex adjuster)
> has the identical stamping on its rear pivot plate; the only difference being
> that the lettering is the "open C" and "flat G" type.
> Logic tells me that the barrel adjuster was a feature that was added later on
> to improve the product.
> Any input that anyone has would be greatly appreciated.
> A gloomy day in Palo Alto, CA
> Ted E. Baer