HD Vehicle Identification Numbers

For model years 1905-69 engine numbers represented the vehicle identification number (=VIN). There are no VIN numbers whatsoever stamped onto the frame. These VIN are easy to decode and self explanatory. The first two digits show the model year, the following 1, 2 or 3 letters represent the model and the final four or five numbers represent sequential production number. Between 1960 - 69 the production number portion was also coded. For even years, the first digit of the production number was even and for odd years this number was odd — This peculiarity makes it harder for forgers to get it right.

① = model year
② = type
③ = serial number

With the growing number of Harley models the VIN grew more complex too: Now we have the model type / model denomination in the first group as a combination of one number and one letter. The second group is the serial number, and the last group is made up from a letter and a number. The number is the last digit of the model year. This number is usually preceded by the letter „H“, but not in 1980, when it’s the letter „J“. It’s almost logic :) The three blocks in the VIN are thus:

① = type / model
② = serial number
③ = model year

From 1970 on Harley began numbering the frames. The engine number was punched into a dedicated spot on the steering head. Having „matching numbers“ means the engine / frame combo came straight from the production line. Different numbers mean, someone „customized“ the bike, which can lead to funny (read: nerve-wracking) incompatibilities (read: F@#&!).

The motorcycle is an FX 1200 (Type: 2C), produced in 1976 (Year: H6) with the sequential number 47925.

Milwaukee is sure glad that Harley frames offer abundant space for ever growing VINs: today they contain more information than a peanut tank can hold gasoline. There's the place of production, engine category, sales region (there are varying highway codes worldwide and in the US) and the model range (coded by two letters) whose number is growing steadily. Then there are more codes for engine version, year of make, and, drum roll: the actual production number.

The engines get marked with an abbreviated number, making it easy to decide if this particular engine was meant to live in this particular frame, also known as „matching numbers“.

On the following pages we’re presenting the findings of our years long research into the content of these 9 blocks of numbers: