I have been collecting Nishiki data for several years in an attempt to more accurately determine their age and create a timeline of models. I now have sufficient data sets and confidence to report the results for serial numbers from the 1970s to mid 1980s, however sufficient data is lacking for the late 1980s onward.
Serial number format XYZZZZZ where:
X is a letter indicating the market using the following codes:
C = Canada (pre-1985)
K = USA (pre 1985)
W = USA (1985-1987*)
Y is a letter indicating the last digit of the manufacturing calendar year,
where A =1, B = 2, C = 3… J = 0. Exception is letter S, used on all frames
prior to 1975.
ZZZZZ is a five or six digit number, apparently representing a sequential frame
manufac turing number for the year (or era in the case of pre 1975 frames)
Example 1: KA24587 is the 24,787th frame produced in 1981 for the US market.
Example 2: CG231117 is the 23,117th frame produced in 1977 for the Canadian
market.
Example 3: WE54612 is the 54,612th frame produced in 1985 for the US market.
* Serial number format may extend beyond 1987, but there are no reported examples,
to date.
Two part serial number, with first part designating manufacturer, month and
year. The date codes data is generally stamped on the drive side dropout.
Format G MM YY where,
G = Giant
MM = month where 01 = Jan, 02 = Feb, etc.
YY = year where 80 = 1980, 81 = 1981, etc.
Example: G0384 is a frame that was manufactured by Giant in March 1984.
* The serial number format may extend this range, in either direction, but to
date no examples have been reported.
