Mountain bike dating
[Atom] [Brooks] [Campagnolo] [Dia-Compe and Weinmann] [Huret] [Maillard] [Normandy] [Nitto] [SR (Sakae)] [Sachs-Huret] [Shimano] [Strong] [Sansin] [Sunshine] [Sun Tour (Maeda)] [Sugino] [Tange] [Williams] [Dancing Chain] [Saddles]The date of manufacture of a bicycle's components can often be used to determine the date of manufacture of the bike itself.
Some bike parts have a date code cast or stamped into the piece.
For old Treks, 27.2 is the most common, but for other bikes the diameters can range from 25mm to 33mm.
The rear derailleur can often be dated to a year or two by referring to the book "The Dancing Chain - History and Development of the Derailleur Bicycle", by Frank Berto, 3rd edition 2009.
Even those equipped with Suntour Superbe components usually had SR seatposts.
Virtually all of the Treks not equipped with Campagnolo or Shimano Dura-Ace components, started life with some grade of SR seatpost and may also have SR stems, bars or cranks.The rear derailleur freewheel/cassette and chainwheels are probably the first to be changed on a bike.On a vintage bike in excellent condition (that apparently had a lonely existence in a garage) all of the components likely are original.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.