*The serial number format changed in 1987. Yy = Year where 80 = 1980, 81 = 1981, etc.ĮXAMPLE: G0384 is a frame that was manufactured by Giant in March of 1984.
Mm = month where 01 = Jan, 02 = Feb, etc. The date codes data is generally stamped on the drive side dropout. Two part serial number, with first part designating manufacturer, month and year. Serial number format may extend beyond the stated end date but there are no reported examples, to date. Exception is letter S, used on all frames prior to 1975). Kawamura manufactured frames (1972–1987): These frames used a serial number XYZZZZZ format where: Serial Numbers for Nishiki bikes were decoded by Tom Marshall, Canadian engineer, racer and runner, using a trial and error database methodology
