Harley-Davidson Codes

Deciphering (Well, Maybe) The Harley-Davidson Codes

Forget about deciphering the Rosetta Stone and ancient Egyptian hieroglyphics. We’re after the big cheese of codes. And that would be Wisconsin cheese. Case in point, what do all those numbers and letters mean when confronting the odd and obfuscating system employed by Harley-Davidson over the past 100 years to designate the company’s bike models? From the first F-Head and Model O to the Es, Us, Vs, and Ws to the FLSTCI and beyond, it can get confusing. But beneath the arcane mutterings of alphanumerical mumbo-jumbo, there is some method to the Milwaukee semi-madness. But right from the get-go, we ran into some major controversy.

In conducting research for this article, we spoke with several restorers/historians/collectors and also chanced upon a book written by Herbert Wagner, an authority on Harley-Davidsons and the author or contributor to five books on the subject. He also served as a consulting historian for H-D’s annual reports. In discussing his fifth (and especially significant) book Myth, Reality, and the Origin of the Harley-Davidson Motorcycle, 1901-1909, he says his research had shown “how the story of Harley’s beginnings had been thoroughly screwed up by past generations of deceptive advertising.” He goes on to say that H-D even got its own birthday of 1903 wrong and that the first Harley-Davidson motorcycle did not appear in the historical record until the autumn of 1904, while marketing attempts didn’t begin until 1905. In fact, his research findings demonstrate that the first complete H-D wasn’t sold until 1905 to a Wisconsin country mailman, Peter Olson. Wagner calls the 1903 founding date a “creation myth” and goes on to say that, first in 1908 and again in 1970, the company issued this incorrect historical information. (You can probably see where this is going relative to our quest for the accuracy/interpretation of Harley model designation and nomenclature.)

Wagner even sets the mystery off and running when he mentions that H-D began numbering its bikes in 1909. He asked, “So what happened to 1903-1908?” No answer. Whatever the accuracy of the founding year, he also says, “For me, the folklore and facts surrounding early Harley-Davidson only add to the company’s famous mystique and allure. After all, baby Harley-Davidson wasn’t writing history, baby Harley-Davidson was making history. In fact, the Harley motorcycle of 1905 helped set the pattern for all American motorcycles to the present day. Other builders-including Indian-would follow Harley’s lead. Incredibly, in 1936 Bill Harley and the Davidson brothers did it again when they re-invented the American motorcycle with their fabulous 61-cubic-inch overhead-valve model, commonly known as the Knucklehead. It all adds up to one thing: While Harley-Davidson might have messed up its early history, Harley-Davidson got its motorcycles right.”

Looking for more answers, we went to Mike Smith, one of the country’s premier bike restorers and motorcycle historians, to give us his take on the H-D numbers game.

He started with a surprise statement. “I don’t think the names came from Harley-Davidson.” “Huh?” we stammered. Then he went on to explain. “I think they probably started out as street-given names. For instance, ‘L-‘ and ‘F-head’ were automotive terms, not Harley terms. The L-head has to do with the flathead car motors like the Ford V-8. Everything had to do with their valve arrangements from the early car days. (The F-head design featured a side-mounted exhaust valve and pushrod-operated overhead inlet valve.) Harley’s very early bikes had letter designations in the company’s catalogs. The serial number on the bike, however, often had nothing to do with the letter in the catalog. For example, the Model 1912 might have had a model A, B, D, D, or F, while the serial number on the bike that they used in 1912 was a “B,” indicating bikes manufactured in 1912, because in 1911 all their motors were stamped with an “A.” Today, people get tripped up on bikes, say the 1917T. In the catalog the number references it as a Boardtrack racer, of which only a couple were made, and are now worth half a million bucks. However, 95 percent of Harley’s street bikes were also marked as a 1917T. The serial number on the bike had nothing to do with the catalog. About 1916 Harley came out with the J Series, and again it had nothing to do with the serial number. When they went to the 74-inch motor, they added the D. The J meant it was a 61-inch, while the D meant it was 74 inches. But now if you look at all the serial numbers that go with the J or JD, they included up to three more letters that further defined the motor-for example, the JDCA. Why they came up with those letters, I don’t know. I’m not sure, but some of the letters might have had something to do with export. The F was also a 61-inch, while the FD was a 74 just like the JD. Other letters further described the compression ratio, whether it was set up for sidecar or sport solo, or whether it had iron pistons or not.”

Mike continued, “In the 1930s, H-D got into the V Series…the VL, the VLD, the VLH…up until 1936. Then they went (and stepped back a letter of the alphabet) to the U Series, which was a flathead 80-inch motor with a recirculating oil-pump system. Then of course they had the E Series, the EL, and the FL in the Knucklehead, right up into the Panhead. Although it was a completely different motor, the only thing that changed was the reference to the head design, still an E or F Series, one a Knucklehead, one a Panhead. That existed until right into the advent of the Shovelhead, still with the F designation.”

If that isn’t exactly as clear as 50-weight oil, here’s a bit of information that could give us a handle on how it all came to pass. Let’s call it “The SOS Connection.” Back in the very early days of motorcycling, you ordered your parts via the manufacturer’s catalog. And you did so via the prevalent means of communication at the time…not by the telephone, but rather by telegraph-i.e., dot, dash, dot. In fact, the motorcycle catalogs listed the parts in alphabetical telegraph code.

We delved into this interesting trail of evidence by placing the question before Buzz Walneck, National Motorcycle Hall of Fame member, who came up with an original Harley-Davidson factory order form from which he read several examples regarding the telegraph codes: “In 1914 if you wanted a single-cylinder, belt drive, you ordered an ‘Acorn.’ If you wanted a Model B with the chain drive, you ordered a ‘King.’ In 1916, if you wanted a three-speed Twin, you ordered an ‘Egg.’ And if you wanted the large seat, you ordered the ‘Acorn Elephant.’ If you wanted a ’24 JD with standard 74-inch motor, cast-iron pistons, and electric equipment, you ordered a ‘Roach.’ And if you needed a ’24 roller bearing for the center rod, the order code was ‘Outhouse.'”

Aha-this could be the smoking gun, the connection between the telegraph, ordering parts, and the fairly weird number and letter designations. The telegraph molded the message. If you get a hold of antique catalogs you can see it for yourself.

One of the first, beyond-early unnamed motorcycles was “The Silent Gray Fellow,” the name acquired by the bike’s gray paint job and reputation for quiet running. Fair enough. “Sport Twin” and “61” were no-brainers, obvious references to engine configuration and engine displacement, respectively. And at this point we first hear the name “Knucklehead,” which appears to have been a popular street name prompted by the resemblance to a fist of the new engine’s rocker covers. This manner of parlance would carry over to the Panhead (’48-’65), Shovelhead (’66-’85), and even the Blockhead (Evolution ’84-’00) as the engines evolved. After the 1999 intro of the Twin-Cam 88, the nickname “Twinkie” appeared in SoCal. We also heard somewhere (maybe over too many beers) that the V-Rod’s engine was nicknamed the “Waterhead.”

The various “Glides” circa ’40s-’70s were factory names. The “Hydra” referred to the new telescopic-fork frontend that debuted in 1949. The “Duo” was so named for its swingarm rear suspension and twin shocks. The Electra-Glide (1965) was a Duo-Glide but now with electric start and a 12-volt system to go with it. The FX Super-Glide (1971) was a semi-blending of a non-electric-start FLH 74 engine, frame, and running gear with the frontend from a Sportster plus Willie G’s “boat-tail” rear end. It’s also considered the first factory production “custom.”

A quick scan of the first Harley-Davidson bikes tells us the factory used the designations 0, 1, 2, 3, 4, 5/A/B/C, 5D…after which you can follow the alphabet over the next hundred years to literally span the letters A through Z. What was the Z Harley, you ask? Why, the ’73-’75 Z90, a 90cc two-stroke wonder. But still the question remains unanswered. Was it just the luck of the draw? Did the FLSTCI (Heritage Softail Classic Twin-Cam 88) simply begin life back in 1918 as the F Model, so designated for its F-head design, and then accrue additional letters as the bike evolved to include FL, FLH, FLHT, and so forth? The “FL” in FLSTCI hearkens back to the F models, while “STC” translates to Softail Classic. So it seems the name game is an alphabet soup. At least in part.

The first Sportster appeared in 1957 under the XL-57 factory designation (and 54 ci). For 2006 the bikes are now served up in several flavors, including the 883-XL 883, 883 Low-XL883L; 883 Custom-XL883C; 883R-XL 883R; 1200 Custom-XL 1200C; 1200 Roadster-XL 1200R; and 1200 Low-XL 1200L. The designations are fairly straightforward and allude to engine displacement (883 and 1200cc), performance enhancements, and bodywork/seat height. But the venerable XL designation is carried forward. So what did XL originally stand for? “X” usually meant “experimental” or “unknown.” “L” could have referred to valve design or just “large,” except the Sportster didn’t have the L-head design, and as far as “large” goes, it’s always been at the other end of Big Twin. Maybe “X” was just the next available letter of the alphabet, or maybe it just sounded more mysterious-a good choice for a new bike. Or maybe it’s none of the above.

We’ll let Mike Smith and Willie G. Davidson have the last word. Said Mike, speaking of some of the factory designations and names, “I don’t know where they come from. Willie G. might know, but every time I ask him he just looks back at me, shrugs his shoulders, and smiles, saying, ‘There’s sooo much still to learn.’ And he’s right.”