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Learning your Harley ABC’s

Harley Davidson 101

Uncle Loomis - Merchandising


So, we’re gonna do a quick & dirty crash course in HD nomenclature. We’ll have a brief history lesson, and then run through current models. This is not comprehensive, nor is it complete - it is a super-fast rough guide!  Factory records are even spotty from some time periods (there was a big fire in the Fifties), and Harley built and did strange stuff over the years.

Respected Harley historians aren’t even in agreement on many aspects of things, especially regarding the early bikes. Remember, the original shop in Milwaukee was akin to your modern bike shop; just a couple of dudes wrenching away. This is intended to be a quick overview to help folks get up to snuff in a hurry. Links are used for photos so this document is not a million pages long - click liberally. I’m gonna go over some of the more common colloquialisms, too, but recognize that there are thousands of common HD nicknames for stuff. If you don’t know what a mousetrap, ratchet lid, Pan-Shovel, or electric foot are, it’s ok. You’ll get there.

Super-glossed-over early-ish Harley Davidson History:

Harley made some weird items. Thumpers. Peashooter flat-trackers. A BMW boxer-copy. (The XA.)  They licensed Aermacchi small-displacement bikes, which were sold as HD products. They built snowmobiles and golf carts. Harley even had the Nova project in the eighties, looking into a liquid-cooled V4. (Hello, VMAX!) 

Not all of this stuff was bad ideas and psychedelic drugs - a lot of their innovations paved the way in motorcycling. They began using conventional hydraulic front ends on the Hydra-Glide in 1949. Bikes got suspension at both ends in ‘58 on the Duo-Glide. The Sportster was the S1000 RR of its day - it was a performance contender; a hot bike; a research test bed. The ‘65 Electra Glide was the first common HD to receive electric starting - take a moment to think about that. In 1963, you could buy a premium, top-line touring bike, and you would be kick-starting its cantankerous ass to life.

None of this is particularly important, but you need to know that Harley was making bikes from the very beginning of history, and they were crude and rough, made to last even if they were not too refined - Harleys are infinitely rebuildable right up through the Evo engine, and usually, the value they command makes it worthwhile to do so. The proliferation of Sportster parts alone speaks to the vastness of this demand. Ask yourself how many of our customers rebuild their Ninja 500’s? If you see an old Shovel on the road, chances are it’s on its third overbore, and probably has had six owners.

They retained their agricultural feel - first out of necessity, and later out of stubbornness -  and some would say never dropped it. Just remember that there is a ton of history and heritage there, and Harley goes to great lengths now to give that ‘feel’ to their modern, polished bikes. Many HD riders are older than us, and remember watching HD lead the game in the old days. Remember, the first Japanese company to even attempt to best HD at their own game was Yamaha, with the 1981 Virago. By all accounts, that was pretty much a failure. (Trust me, I had one!)  Japan kicked HD in the teeth from the seventies on to the nineties, but it was not with HD’s bread-and-butter - heavy touring bikes. Heavyweight V-twins are something Japan still has not figured out how to sell to Americans the way Harley does.

Now, a fast breakdown of the stupid letter system. It didn’t used to suck; that’s recent. The first two letters in air-cooled Harley letter codes back in these days told you about the engine and front tire (well, it was the fork, which governed the tire, but now the tire is really the only semi-reliable way to gauge what fork could be on the bike.)  XL was the Sportster with a 19” or 21” tire (and a Narrowglide). FL was a Big Twin engine with a 16” (or now sometimes 17”) front tire (And the heavy Touring front end). FX was a Big Twin with a 19 or 21” tire, (and a Narrowglide). 

Narrow and Wide Glide refer to the distance between the front fork tubes, by the way. That’s the big deal. They named a whole bike after fork tubes that sit farther apart, swear to God. Original Narrowglides were about 7” center-to-center, and original Wideglides were about 10”. Now there’s a proliferation of forks, tubes, and trees, all of which are reproduced with even different specs by aftermarket suppliers, so the terms are muddy. These days, Wide Glide is the only sure bet, which is the front end that comes on the FXDWG (Dyna Wide Glide). They even make a Mid-Glide nowadays. My head hurts.


FL (Touring bike, big engine) + XL (Sportster, little unit engine) = FX (Super Glide - big engine, sporty-handling front end)... get it?  That used to be pretty much the three models they sold. A chimp could remember those three - and that covered all of ’em, more or less.

The third character to come along was the frame, as Harley started using different ones. (And sometimes the fourth character, too, depending what frame is used - I’m looking at you, Softail.)

The Harley Softail utilizes ST frames. (Usually - sometimes they are simply an ‘S’, like in the FLS Softail Slim.. I hate you, Harley.) Touring frames with fork-mounted fairings are H frames, and Touring frames with frame-mounted fairings are T frames. Dynas are D frames. Rockers, a crazy variation of the Softail, were C frames. Rubber-mounted FX frames are R frames - designed by a young Erik Buell, they are easily picked out by a metric-style ‘triangle’ of frame tubes joining under the saddle. Now, many HD products are rubber-mounted, but when the FXR debuted, it was the first - a real technical innovation.

VRODs are their own bastard child. ‘VRSC’ anywhere is a VROD. Next to nothing on them interchanges with a ‘normal’ Harley.

The rest of the letters after the first 2, 3, or 4 is just options stuff. Some common ones are:

  • SS - Springer Softail
  • SC - Springer Classic
  • WG - Wide Glide
  • FB - Fat Boy
  • SE - Screamin’ Eagle
  • D - Deuce

Current Model Names/Letters

This section is sort of bleed-over from the previous section. It’s born from the wild proliferation of options as customers began demanding more and more crazy stuff. Blame it on the 90’s.

Harley let the letter thing get out of control. Now they try and just use model names, say, in the showroom, but the letters are still there. Old Harley guys ignore them because they make no sense to normal, breathing humans. Hence, if you can figure out really fast that an FLHTCUTG is an E-glide Trike, you’ll look like a genius.

Currently, there are 5 model families within HD. Touring, Sportster, Dyna, Softail, and VROD.

Let’s start with the easy one. Sportsters always start with ‘XL’. There are other letters that can follow, and numbers sometimes indicating displacement, but just remember that an XL is a Sporty, and vice versa. Sporties have unitized motors. To this day, The Sporty has 4 cams, and that atypical-for-HD setup mean that the pushrod tubes run parallel to one another. You can pick a Sportster engine out a mile away because of it. Done.

Next are the Harley Touring bikes. These bikes all have heavy frames, bags, and either 16 or 17 inch wheels on non-CVO models.

(A brief aside: CVO is ‘Custom Vehicle Operations’. It is the performance division of HD. Usually, bigger engines that will later appear in production bikes are showcased here. Crazy paint is the norm, and hot rod parts and trick wheels are to be found. They are pricy. Each year, the group of bikes that are CVO units are dominated by baggers, but Softails and Dynas have made a showing, too. In model letter designations, they are indicated either by the letters ‘SE’ for ‘Screamin’ Eagle’, or simply by an arabic numeral, like FXWG3). 

There are really only three types of touring bikes - those with batwing fairings (named, duh, ‘cause it looks like a bat wing), those with glass,  and those with sharknose fairings (These look like a, uh, nose. Like, on a shark.). Batwings mount to the forks, sharknoses mount to the frame, and I assume you all know what a Plexiglass windshield looks like. If you wiggle the bars and the headlight moves, it’s a batwing. If you move the bars and the headlight points down the road still, it’s a sharknose and a Road Glide, one in the same. If it has just a windshield, it’s a Road King. Road Glides with the frame-mounted fairing start with model code FLT, every other Touring bike is an FLH.

  • Electra Glide - Batwing fairing and Tour-Pak. Tour-Pak is the pizza-box looking thing behind the passenger seat. It comes as a trike, too.
  • Street Glide - Batwing fairing, no Tour-Pak. Note that one can add a Tour-Pak to the Street Glide, and the bike is simply a Street Glide with Tour-Pak; it doesn’t become an E-glide. Also came as trike for a coupla years.
  • Road King - Heavy Tourer with windshield; no fairing. Easily the most traditional-appearing Touring bike in the lineup.
  • Road Glide - Sharknose fairing.

Moving right along, we now have Softails.   They’re easy to spot - they have a hidden rear suspension that looks like a hardtail at the rear triangle. Popular ones include the Heritage Softail, the Fat Boy, and the Night Train. Pssst... they’re pretty much all the same bike, even though they look crazily different!  Their whole goal is to look like rigid-rear bikes. Pose much?

They come in two main varieties:

  • FXST - Softails with a front tire 17” or larger (narrow forks)
  • FLST - Softails with a front tire 16” or smaller (wide forks)

Some oddities about Softails - they came in 150 AND 200mm width rear tires, depending on size. There are some letter codes that buck the trend - the Softail Slim, for instance, is an FLS. Why?  Because it’s Harley; they can do whatever they want. Honestly, FLST was already taken, and to start stacking more letters in was going to be ridiculous... they really are pushing for model names nowadays in common parlance. The new Blackline is the same way - it’s an FXS. Why?  FXST was taken, and to use a different name, they’d have to make alphabet soup. To make matters more confusing, before the ST (Softail) frame existed, an FX-framed bike was a Super Glide!  So, if a rookie tells you he has an FXS, it might be a Shovelhead with exposed rear shocks, or it could be a Twin Cam with hidden rear suspension.

Incidentally, if anyone tells you they have a ‘Springer’, the Softail is the only modern bike Harley put springer front ends on. They will fit on other stuff and guys do it... but HD only ever put them on Softies.

There’s one caveat here in the Softail category - Heritage Softails. Man, they look a lot like a Road King. They’re patterned, really, after an old Hydra-Glide; meant to look suspended in front, and rigid in the back - look for the ‘rigid’ triangle at the rear!  Road Kings are patterned after the old Duo-Glide; they’re not trying to trick your head into thinking that they don’t have rear shocks.

Well heck, this is easy, right?

Next up are VRODS. Liquid-cooled, motors Porsche had a hand in. I’m pretty sure these bikes are not actually Harleys. Again, pretty much all the same thing. The letter code on all of them will go VRSCsomethingsomething.

Finally, we have the Harley Dyna. The cheapest way to get into a Big Twin, this model is easily distinguished by its exposed rear shocks. They all start with FXD, with the exception of the new Switchback, which is an FLD (because it has the little front wheel and is the only Dyna to have the wide-ish Touring forks).

Harley Engine Names

They’re not separate from the bikes, they’re in conjunction with them. Realistically, you could refer to your bike as a Blockhead, a Dyna, a Wide Glide, an FXDWG, a Big Twin, or a Harley, and still be pretty spot on with all of it. And I think that most people just feel cool when they talk about a “Panhead”.

Harleys from the old days did not differ much from one another, and the models were often just referred to by their powerplant, which were usually nicknamed due to the shape of their rocker box covers. The practice stuck, even when a bike name would have been more helpful, but people do what people do. Most older Harleys wind up getting cut up into Frankenbikes, so it at least gives people an idea what era the bike came from. Basically, there are two groups:  Big Twins, and Everything Else. Big Twins have separate transmission assemblies. Roughly, here’s what you’re looking at:

Notable Players in the Everything Else Category - all are unit motors except the 45. None are considered Big Twins.

  • 45 (Flathead) - ‘29 to ‘73. Found in motorcycles until ‘52, then its use was relegated to the Servi-Car (letter code G), a little run-around trike originally meant originally for automobile dealers, but later outfitted for all sorts of urban delivery. Not usually lumped in with big twins. Also not to be confused with Big Twin flathead. This one’s kind of a freak, don’t worry about seeing one, they’re pretty rare and slower than all bejesus (50 mph on a good day with a downhill stretch and a tailwind.)  Oddly, they were pretty much unchanged up until the seventies, so you were really riding history, even back then...
  • Ironhead - ‘57-85. Found only in XL models (Sportsters). Motor is different from big twins in a variety of ways - 4 cams instead of one, and is unitized (trans and motor are all in the same casting). It’s easy to pick these out; the pushrod tubes are parallel to each other. Existed in a  900 and 1000cc version.
  • Evo Sporty - ‘86-present. Sportster only. Comes in 883 and 1200 cc versions.

Big Twins - non-unit motors. Liquid-cooled Revolution engine (i.e. the Harley VROD) is not considered a Big Twin.

  • Flathead - ‘30-’41. 74 ci, and later, an 80 ci.
  • Knucklehead - ‘36-48. 61 ci, and later, a 74 ci.
  • Panhead - ‘48-’65. 61 ci, and later, a 74 ci.
  • Shovelhead - ‘66-’84. 74 ci, and later, an 80 ci. A word of note:  Shovels from ‘65-’69 were made with Panhead-like lower ends, which had a generator and magneto, rather than a stator and points. They have flat sides, and are commonly called Pan-Shovels or Slabside shovels. The later Shovels are Cone Shovels.
  • Blockhead - ‘85-’99. All Blockheads are 80 ci. A word of note: Also called Evolution or Evo, this engine is not to be confused with Sportster Evo... same name, different engine.
  • Twin Cam - ‘99-Present. 88 ci, 96 ci, 103 ci, and 110 ci. Also called the Fathead, this differed from all previous Big Twins by having more than one camshaft in the engine. Looks like the Evo a bit, but can be told apart by rocker box bolts (3 on the right edge, instead of Evo’s 2) and the distance between tappet blocks. (Evo tappet blocks are almost touching, the Twin Cam’s are a few inches apart due to the extra cam in there.)  It has been HD’s practice to debut a bigger engine in CVO bikes. That CVO engine, in a few years, becomes a new production engine. For example, the 110 ci engine is now in CVO bikes. The Street Bob and Super Glide come equipped with a 96 ci engine. All other Big Twin bikes have a 103 ci engine at the time of this writing, which was for a short time the CVO engine.

-- Uncle Loomis