The small hole a few mm above the derailleur socket was a spring anchor, as you surmise. No mystery, though: it was required for the Campgag "Sport" derailleur. That ugly varmit had only one pivot, and only 1 roller. It was rated for sprockets from 16 th all the way to 22. Other than having a parallelogram design and construction like the Gran Sport (and later steel Record of the early 1960s), it is generally considered an object of scorn, something to be kept as an example of stupid Campy designs. Yeah, we know the rationalizations, but let's get real. Most of the cost of the Gran Sport, and little of the performance. Maybe in the early 1980s, I bought two, NOS, @ $5 each. One still graces my campy parts box. The other went on a framed plaque I gave a good biking friend when he completed his M.E. PhD. Sort of an ironic symbol of lousy designs.
harvey sachs mcLean va
Bob Hanson wrote:
I noticed that early Campagnolo 1010 dropouts had a small hole drilled through just above the derailleur hanger. I would assume that this was for direct mounting of a non-Campy derailleur with an upper pivot spring. By catalog #17 (c.1973) this feature was eliminated from the 1010 dropouts.
Curious about this, I just removed the spring stop from the mounting bolt of an early Super LJ derailleur and bolted it directly onto an early '60s frame with this type of Campy dropout. Voila! a perfect fit.
However, this feature dates back to the earliest appearance of these dropouts (so, at least back to 1953) - many years before Simplex's first parallelogram derailleurs.
Does anyone know which derailleurs this originally may have been intended for?
Also, why would this have been eliminated? - Especially, when other brands of superior derailleurs were increasingly incorporating springs with their upper pivot bolts... (or, perhaps I have just answered my own question here).
Bob Hanson, Albuquerque, New Mexico, USA