Schwinn serial dating
We've done a few things to make it more likely that you'll find the bike you're looking for. The letter "G" followed by a two-digit month code (01 = January etc.) and two more digits for the production year (81 = 1981 etc.).
This could also work for January back to a previous year.
Date Codes occupy the first two, three or four positionsin a serial number.
Mass produced Schwinn bikes have been data-coded since1965 by the first two letters in the serial number.
Bicycles from Japan will have Serial Numbers located on the left, rear axle hanger, on the bottom bracket shell or on the lower section of the headlug.
The number will have a production month letter in either the first or second position and a production year number in the other (first or second) position. For some Japanese built Schwinns the headbadge will have a 4-digit stamping that represents the assembly date and consists of the ordinal day and the last digit of the year (2456 decodes to the 245th day of 1976 or 1986 -- use decals and components to determine the decade).