I was wondering if anyone who is a whiz with Fuji serial numbers might be able to help me out.... According to the information that they have over on Classic Fuji and in a much earlier thread here, the normal serial number pattern for the mid 1970's would be:

YYXZZZZZ

YY = Last two digits of the year
X = Letter indicating the month of production
ZZZZZ = Individual frame number

The general consensus seems to be that the individual frame number is the sequential number of that given model made during the month in question. Thus 76A12345 would be the 12345th Fuji "whatever" made during January 76, 76B00123 would be the 123rd Fuji "whatever" made during February, and so on.

Looking around at the few other examples of the high-end / hand built Fujis from the era, I'm noticing a pattern wherein the first number after the month code is either a "5" or a "0" - e.g. 75A00012 or 75A50012. With some of these bikes, the manufacture of 50000+ in even a year seems highly unlikely, let alone per month. Thus, I'm wondering if the "5" means something else, and if so, what?

Granted my sample set is pretty small, so examples to the contrary would be welcome.

FUJI Serial Number Examples

Doesn't really answer the question though. There is either another numbering system that remains elusive, or there were 50000+ other Professionals cranked out the same month as mine.

The Fuji serial numbers of that format were in use from 1975 to 1979.

In the serial numbers that I have seen there have been four different digits in that position: '0', '1', '5', '9'.

I have seen the Gran Tourer model serial numbers with each of these four digits in the fourth position of the serial number.

I have seen the America model with the '0' and '5'.

My sample size is not large, but I cannot see any pattern as yet.

My three mid-70s Fuji I have bought new had the Showa year type serial numbering system. All were built in 1974 but the last one was most likely a 1975 model year since it was built so late in the year (September) and a low sequential number

Special Tourer F9B18529 bought May 1974 - stolen at four months old, replaced with:
Special Tourer F9B18546 - sold in Oct '76 so I could upgrade to scratched floor model
Special Road Racer (S-10S) K9I003xx (which I still have so keeping last digits hidden)

I'm guessing that the first character is the manufacturing plant.

Here's a 76 America that fits your code. April 76, frame number 01582

One possibility that comes to mind, now that I think about it, is that perhaps those digits represent the manufacturing facility during those years. Other years they might have used a letter to indicate the same thing.