Schwinn code dating prodating oni cc gb page 1
Unfortunately, an office fire in 1948 destroyed the Paramount records.
Numbers mostly followed a three-digit format – often but not necessarily with a “P” as the prefix.
Some Japanese bikes may have an 'X' in the month position of the frame serial number.
Gene from web site provided this great info on figuring out your old trusty Schwinn; Schwinn Bike Dating After 1965, Schwinn serial number sequences, while appearing to beconfusing on first sight, follow several general rules.
The firstletter tells production month, the second tells production year.The Chicago Serial Numbers consist of a letter representing the month of manufacture, a number indicating the last digit of the year (1960 - 1964; 0=1960, 1=1961, etc.) or a letter indicating the year(1965 - 1979; A=1965, B=1966, etc.), followed by a sequential series of five or six digits (e.g. If letters were used for date codes, they skipped the letters "I" and "O" as they looked too much like numbers.Note: This scheme is for all Chicago built non-Paramount models excluding 1962-1963 Superiors, 1964-1969 Super Sports and 1968 S/S Tourers (whose Serial Numbers are located on the left rear axle hanger and consist of a single letter code for the month [again, skip "I" and "O"], the last digit of the year and a 3-digit sequential build number -- e.g.The first possible location is on the underside of the bottom bracket.Sheldon Brown's Bicycle Glossary defines the bottom bracket as "the part of the frame around which the pedal cranks revolve." Turn the bike upside down to view it better.
We found a very early Paramount – claimed to be a 1938-9 vintage – with serial number A545.