The chain hanger was introduced at the '77 Milan show. My assessment is that the frame manufacturers probably initially used the new hanger dropouts (commonly referred to as 1010/B or 7180011right rear) only for the bikes that were to carry the hanger. They probably wanted to use up their supply of existing dropouts before ordering a quantity of the new ones. Once that existing supply of dropouts was used, all the frames incorporated the new dropouts, even though they were not slated to receive the hanger. I've seen frames up to about '84 still incorporate the hanger dropouts. However, I think the hanger dropout (right rear only) was discontinued a year or two prior to '84.
I use the rule of thumb: Frames that incorporate the hanger dropout, typically can be dated from '77 on.
The framebuilders on this list probably know exactly when the right rear hanger dropout was being discontinued by Campy.
Marc Boral Long Beach, CA
-------Original Message-------
From: Lee Berg Date: Friday, October 26, 2001 8:13:30 AM To: classicrendezvous Subject: [CR]"Last" years for Campagnolo chain hanger dropout bikes?
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.