How long was the period of appearance in factory production bikes of the Campagnolo two-bolt-hole chain hanger short dropout? Did they appear for a short, distinct period (e.g., a year or two after introduction around 1979) so that a production bike that has these dropouts could be dated within a couple of years? Or did they continue to appear on production bikes for several years after their introduction?
Lee Berg
Palo Alto, Calif.