Diamond Back Fairly Serial Number References

The Fairly Bike Company is a Taiwanese bike manufacturer. Diamond Back used The Fairly Bike Company to manufacture their later frames. Due to costs risings due to foreign exchange changes in the Dollar, Diamond Back began moving their production to Taiwan from Japan (Koizumi). Whilst higher-end frames such as the Harry Leary Turbo and Formula 1 continued to be produced in Japan by Koizumi, the majority of Diamond Back models moved to being produced in Taiwan.

Diamond Back Taiwanese BMX Frames

Fairly frame numbers appear underneath the bottom bracket and begin with the letter F. A common myth is that the F in the serial number stands for Formosa, but this has been proved to be incorrect.

Fairly Frame serial number breakdown
Fairly Frame serial number – bottom bracket

Decoding Diamond Back Fairly frame serial numbers

Fairly frame serial numbers start with the letter ‘F” and are then followed by 7 digits denoting the year and month of manufacture as specified below. As with Koizumi serial numbers, it is not possible to derive the model of the bike frame from the serial number alone.


The Fairly serial numbers can be broken down as follows:


  • The first letter is always ‘F’ for Fairly bike company


  • The second digit, which is a number represents the year. This is as follows:
    • 3 = 1983 (this is the first year Fairly produced bikes for DiamondBack)
    • 4 = 1984
    • 5 = 1984


  • The third and fourth digits are simply numbers which represents the month of manufactuer as follows; A leading ‘0’ (Zero) creates a visual consistency.
    • 01 = January
    • 02 = February
    • 03 = March
    • 04 = April
    • 05 = May
    • 06 = June
    • 07 = July
    • 08 = August
    • 09 = September ( The letter ‘I’ was replaced with an ‘X’ so as not to be confused with a ‘1’ (One) )
    • 10 = October
    • 11 = November
    • 12 = December

Production number

  • The last 4 digits, which are numbers, simply represent the number of that frame that month. Where 0001 is the first, 0002 is the second etc.

What is the backwards C?

Occasionally, you will see a letter or numeral that appears to be a capital ‘C’ but is written backwards. This is in fact just a ‘0’ Zero which has been mis-stamped and not fully forming the letter.

Decoding Diamond Back Fairly fork serial numbers

Fairly produced bike forks don’t have serial numbers as far as we know. You will find the words Akisu or CR-MO stamped on early models.


Fairly made Diamond Back BMXs

This is a list of framesets made by Fairly for Diamond Back