The Schwinn serial number DU505908 indicates that the bike was manufactured in 1980. Schwinn used a specific coding system where the first letter represents the year, and "D" corresponds to 1980. The following digits provide additional information about the production sequence.
2003
The Schwinn bike serial number H19577 was made in 1951.
1984
August 1974
To determine the year a Schwinn Jaguar bicycle was made based on the serial number, you typically need to reference specific Schwinn serial number charts. The serial number you provided starts with "sd," which indicates it may have been produced in the late 2000s. For an exact year, you might want to consult Schwinn's official resources or vintage bicycle databases.
June, 1967
November of 1981.
FEBRUARY 1974
85
I just searched for the serial number of my Schwinn Collegiate. From the same source it appears that mr850439 was manufactured in December 1980. Here is a reference: http://www.bunchobikes.com/serialnumber5.htm
If the serial # is on the headtube, that bike was made in Chicago in October 1975.
1977 would be my guess