FL Duo-Glide

Harley-Davidson FL Duo-Glide Harley-Davidson

This site is a tribute to the most beautiful bike ever made,
the Harley-Davidson FL Duo-Glide.

It pretty much goes without saying that the Panhead engine is the most aesthetically pleasing engine that the Harley-Davidson Motor Company has ever made, and it is the opinion of this author that it is the 1960 to 1964 FL Duo-Glide that is the most aesthetically pleasing of the motorcycles that carried this engine.

Pan Head Engine

The Panhead succeeded the Knucklehead in 1948 as Harley's main overhead valve engine. I say "main overhead valve engine" and not "big twin" because the biggest Harley engine at that time was still a side-valve engine. 1936 was not only the debut of Harley's first overhead valve engine, the 61 cubic inch EL Knucklehead, but also the debut of the VL 80 cubic inch side-valve engine. It was not until 1941 that the 74 cubic inch FL was available (the Second World War halted production of this bike, making the "74" Knuckle a rare bike), and not until 1970 that a 80 cubic inch overhead valve engine was available in the form of the "alternator" Shovelhead engine. Although the 80 cubic inch VL was bigger, the 61 cubic inch EL was more powerful.

Side Note: to keep things simple I've stayed away from getting really technical with model nomenclature, so don't e-mail me about how I've oversimplified it. As far as I'm concerned, Harley-Davidson overcomplicated it.

Like the Knucklehead, the Panhead was available in the 61 cubic inch EL model as well as the 74 cubic inch FL model. In essence the Panhead was a Knucklehead with new cylinders and heads. The Panhead had aluminium heads, hydraulic valve lifters, internal oilways, and chrome plated rocker covers shaped like cake pans, which led to the "Panhead" nickname. 1952 was the last year of the 61 cubic inch EL, and the 74 cubic inch FL received major engine revisions in 1953 and 1956.

Duo-Glide Ad

The last year of the Panhead was 1965, which was also the year of a major revision in the form of 12-volt electrics and an electric starter. The reign of the Panhead gave way to the Shovelhead, but again the differences between the Panhead and the Shovelhead, like the differences between the Knucklehead and the Panhead, were not earth shattering. The Shovelhead underwent major revisions in 1970 when its generator was replace by an alternator, thereby changing the shape of the bottom end, which has lasted through to the V2 Evolution engine, and the Twin Cam 88 engine.

In adding an electric starter, the Duo-Glide became the Electra-Glide. While the first year Electra-Glide still had the beautiful Panhead engine, in its place of the beautiful oil tank was an ugly box to hold the battery. This ugly cover has continued to deface bikes even to this date. Some models even enlarged this eyesore to cover the transmission. The best solution to the problem of hiding the battery is found in the Softail models: wrap the oil tank around the battery compartment.

The aesthetically pleasing qualities of the Panhead engine and the simplicity of the Panhead and Shovelhead have given birth to the Neo-Pan engine by Panzer Motorcycle Works USA. In an age were motorcycles have fuel injection and computer chips that need special diagnostic equipment, some are returning to the basics, and what better way to do that than with the beauty of the Panhead. Panzer took the best parts of the Panhead and the original Shovelhead (as oppose to the "alternator" Shovelhead) and combined them with modern technology and metallurgy. In addition to Panzer, there are a few other companies that are making Panhead replicas.

In addition to the beauty of the Panhead engine there are a few other details that I think make the Duo-Glide the most beautiful bike ever made, such as the suspension. When the Panhead first came out in 1948 it retained the same suspension that Knucklehead bikes had, which was no suspension in the rear end and leading-link sprung forks in the front end. 1949 saw a change in the front suspension with modern oil-damped telescopic forks, which not only gave better handling, but also looked better. With the advent oil-damped telescopic forks, the bike was dubbed the Hydra-Glide.

Light Shroud

Another Side Note: remember, this is my opinion, so you springer fans don't have to e-mail me to say that springers look better. I do acknowledge that a chrome springer front end is very beautiful.

While the front end of the Hydra-Glide looks nice, the original headlight housing does look a little weak (left in the blue). The 1960 Duo-Glide made an improvement with a two-piece stamped aluminium fork nacelle that shrouds the headlight (left in the red).

From the Hydra-Glide, the next logical step was the Duo-Glide, that is, hydraulic suspension at both ends, which came in 1958. Having a swingarm rear end was a major improvement, but the Duo-Glide was not the first Harley with rear suspension. The first Harley with such a rear end was the Model K, which was introduced in 1952 and eventually evolved into the Sportster.

Many will say that a rigid rear end is the ultimate in motorcycle aesthetics, but to me it just looks painful, even when the seat is sprung. As well, the rear springs and shock absorbers gives the rear end more meat to it, while a rigid rear end seems a little empty. Of course the rear springs and shock absorbers must be shrouded in a chrome cover.

The modern Softail models are an attempt to look like a rigid rear end, and they do a pretty good job, but by looking at the rear fender is it obvious it's not a rigid rear end. Anyway, why hide the rear springs and shock absorbers when they look good out in the open.


There are a few other details that are required to make the most beautiful bike, which are not necessarily stock. One necessity that was stock on the Duo-Glide is the 1 to 12 speedometer. Dropping all the zeros on the speedometer makes it look less cluttered, and definitely more aesthetically pleasing. It has to be 1 to 12, even in countries like Canada were they use kilometres rather than miles. It's not that difficult to memorise the main conversions.

Other necessities that are not stock are dual fishtail exhaust; and more chrome, such as on the oil tank, handle grips, and the kick start pedal. Speaking of which, since it wasn't until the Duo-Glide turned into the Electra-Glide that an electric starter was added to the bike, the Duo-Glide had a kick start pedal. Even the original Electra-Glides had a kick start pedal in case the electric starter failed. If you are building a modern replica of the Duo-Glide that has a very reliable electric start system, the aesthetic qualities of the kick start pedal cannot be over looked. In such a bike the battery compartment must be hidden by wrapping the oil tank around it, and the kick start pedal must be fully functioning. The fake ones are, after all, just that, fake.

One change that is necessary on a stock Duo-Glide is to get rid of the sprung seat. The Duo-Glide has rear suspension; therefore, it does not need a sprung seat. I don't know why this was retained in the Duo-Glide. With a rigid rear end, a sprung seat is a necessity, except for masochists, but it looks ugly. So, if it's not necessary, get rid of it.

So there you have it, the 1960 to 1964 FL Duo-Glide is the most beautiful bike ever made by the Harley-Davidson Motor Company. I admit that a stock Duo-Glide needs a few cosmetic changes, but over all, it's the nicest looking bike that Harley-Davidson ever made.

Duo-Glide Photo Gallery

The Sportster Classic

Harley-Davidson Motor Company - the official web site
Panzer Motorcycle Works USA - makers of the Neo-Pan Engine
Ratpan's Panhead Pages - dedicated to Panhead Motorcycles