Harris,
it's easy to date your shimano.
Almost all shimano parts have a two letter code stamped on them that is the date that part was made.
1st letter is the year, and 2nd is the month of manufacture.
A 1976. A DEC B 1977 B JAN C 1978 C FEB D 1979 D MAR E 1980 E APRIL F 1981 F MAY etc
If you bike was bought in sept of 81, it was probally build 6 months before.
Check it out!
Grant McLean
toronto, canada
Message: 3
Subject heading pretty much tells it all.Other thing I noticed when I pulled
it out to check,the headset is alloy and it just says Shimano 600.
Harris Spracher
Waynesboro,Va.