)Most early Treks (1976 through about 1980) were sold as framesets.
The components were added by the local bike shop or by the buyer. Components also could be swapped from an existing ride to the new frameset.
Feel free to quote small parts of the information on this page, but copyright law requires be listed as the source of the information.
In this website, we credit the people involved in the understanding of these codes. (Naturally, for information provided by others, such as for the Campagnolo and Williams codes, the original source should be cited.)Ben writes: "Brakes and brake levers often have date codes on them.
The rear derailleur freewheel/cassette and chainwheels are probably the first to be changed on a bike.