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Old 02-22-06, 08:52 AM
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The following represents the current understanding of the various serial number formats used on Centurion models marketed by Western States Imports in the USA. Serial numbers were statistically analysed and the results compared against component date codes and extant literature.

1980-1990 Japanese models:

Most Japanese models during this period use a serial number format WXYZZZZ where;

W = a letter, purpose uncertain, but probably indicates manufacturer or Centurion
X = a number, indicating the calendar year of manufacture
Y = a letter, indicating the fortnight of manufacture (A = wk 1 & 2, B = wk 3 & 4, etc)
ZZZZ = four digit number, probably indicating frame number during fortnight

Example: N4E0283 indicates the 283 frame manufactured during the period of weeks 9-10, for the year 1984.

The letter prefix for these codes is typically 'N'. It has been suggested that this represents National, the Japanese market brand for Panasonic, which are built my Matsu****a. While the Panasonic branded models use a similar format, there is no prefix letter, nor is there a letter prefix on the Matsu****a manufactured Schwinns. This suggests the N-codes are be another manufacturer. reportedly Tano, though this is unconfirmed.

However, a number of circa 1984-1985 Centurion have turned up that match the Matsu****a format.

Miki manufactured models (circa 1975-1980)

During the late 1970s, Japan based Miki appears to have manufactured the upper end Centurion models for Western States Imports;

Serial number format Myfxxxxx, where,

M = Miki
y = number indicating year of manufacture
f = letter indicating fortnight of manufacture (i.e A = weel 1-2, B = weeks 3-4,,,,Z = weeks 51-52)
xxxxx = sequential frame number within the fortnight

Example: M7C11265 is the 11,265th frame manufactured by Miki during the 3rd fortnight of 1977.

Katakura manufactured models (mid 1980s)

Japanese manufacturer Katakura appears to have manufactured some bicycles for Western States Imports during the mid-1980s.

Serial number format Kmyxxxxx, where;

K = Katakura
m = letter indicating month of calendar year (i.e A = January, B = February, etc.)
y = number indicating last digit of calendar yaer (i.e. 4 = 1984, 6 = 1986, etc)
xxxxx = numbers, probably indicating sequential manfacturing number during month

Example: KG511505 is 11,505th frame manufactured by Katakura during July 1985.

Note: this serial format can be easily mistaken for the Kawamura format used on many Nishiki models.

China Bicycle Company (circa 1988- 199?):

Circa 1988. China Bicycle Company starting manufacturing low end Centurion and Diamonback models for Western States Imports and they purchased WSI cira 1990. The serial numbers associated with these models are often U-codes, so this may indicate China Bicycle Company.

Serial format Uymmxxxxx, where;

U = China Bicycle Company manufactured models(corroboration req'd)
y = last number of year of manufacture (i.e. 9 = 1989)
mm = number indicating month of manufacture (01 = January, 02 = February,,,,, 12 = December)
xxxxx = sequential manufacturing number within month

Example U91013632 is the 13,632nd frame manufactured during October 1989.

1970s lower end models:

This group consisted of few samples and several formats. Unfortunately, I do not have sufficient Centurion literature from this period to correlate the data to model years and any statements on the serial number format would be pure speculation.

One cautionary note pertaining to the year indicators is that they appear to represent a calendar year and not a model year. Frames produced in the latter portion of the year may be production for the following model year. Unfortunately, there is no way of knowing the cut-off point and it probably floated somewhat from one year to the next. In such cases, you need to use graphics, component mixes or other tools to positively identify the year.

Hopefully, this will be of some use to Centurion owners. I am still willing to accept data on Centurions / Diamondbacks and help in dating models. Hopefully, we can get some more data for 1970s and CBC models. Again, thank-you to all the forum members who participated.

Last edited by T-Mar; 05-03-17 at 04:51 PM.
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