Fuji serial number work like this the S means subcontractor/or aplant manufacture the L means the month starting January as A, febas B and so on the 1 stands for the year of the bike 81 2 would be82 and so on the rest of the numbers are production total for thatmonthso your bike date is December 1981 total production in Decemberof 3,413 to be honest with you that's not alot at all i have about60 fuji bikes but mine are 23,000 built in one month so yours itscool save itFrom what I can tell, it is next to impossible to trace the ageof most bikes with the serial number. However, many of thecomponents will have date codes on them. You just have to knowwhere to look and what to look for. At the time of production, boththe component manufacturer and the bicycle manufacturer will havehad a certain amount of inventory that might correspond to a fewdays up to six months or even a year if they are very sloppy. So Iwould figure about six months after the age of the component toguestimate the age of the bike. Also, keep in mind that the newyear's models could be introduced prior to the end of the calendaryear.The web site below has very useful info on the location andmeaning of component codes.
Registering a bike requires you to know its serial number. But do you know how to find the number, or what it even looks like? This short video explains how serial numbers work, the most common locations on a bike, and what to do if you can't find the serial number. What bike serial numbers are - and where to find them.
Although it is a Trek site, it isequally useful for Fuji owners. I was able to use this info toidentify my Fuji Allegro as a 1985 model.
![Bicycle Bicycle](/uploads/1/2/5/6/125625970/879690985.jpg)
It had a date stamp ofDec 1984 on the inside of the brake extension lever. I had tounscrew a bolt and take it off to see the code.http://www.vintage-trek.com/componentdates.htm.