Later Schwinn serial numbers / years made

Bicycles from Japan made in the 70’s have a production month letter in either the first or second position and a production year number in the other (first or second) position. Examples J677123 = September, 1976, 6J77123 = September, 1976.

During the 1980s, Greenville used the old letter-digit
(e.g. F8 = June 1988)system which Chicago abandoned in 1965,
when it changed to the two-letter system.

Some Taiwanese (built by Giant) Schwinns have a date code (on the right rear axle hanger or on the bottom bracket shell) in the format 'Gmmyy'. The letter "G" followed by a two-digit month code (01 = January etc.) and two more digits for the production year (81 = 1981 etc.). An example would be 'G0181' and equates to "Giant, January, 1981".

On bikes made after 1982:
You can find a 4 digit serial number lightly stamped onto the headbadge.
The first three digits are the numerical day of the year,
and the last digit is the last digit of the year.

EXAMPLE:
3654 is 12/31/84 or 94 or? you determine decade.

Generally the 4 digits on the headbadge breakdown as follows: First 3 are the date of build 1 thru 365, the 4th (last digit) is the last number in the year. So "0" probably stands for 1990. If you are not sure which decade the bike is from, check the parts and graphics on the bike to the pictures in the catalog pages.

Most Paramount serial numbers would start with a letter and then 2 to 5 numbers. My 1974 for example is A74149 or the 149th frame from January (A) 1974 (74). Roger