1964 Harley-Davidson FLH Duo-Glide: The Last of the Real Kick-Start Touring Harleys
By Panhead Jim
Most people today have never ridden a kick-start Harley-Davidson, let alone one weighing over 700 pounds with drum brakes, manual spark advance and a 60 year old electrical system. Even among Harley riders, a lot of younger guys have never dealt with anything older than an Evolution motor. Riding a 1964 FLH Duo-Glide is a pretty good reminder of just how much motorcycling has changed over the last half century and at the same time, how little Harley-Davidson touring motorcycles have really changed at all.
On paper, the bike sounds completely outdated. The front brake is cable operated, the motor still relies on a manual starting procedure and the rider is expected to understand things like ignition timing, carburetor adjustment and points ignition just to keep the machine running correctly. The bike weighs over 700 pounds, makes somewhere around 55 horsepower and still expects you to physically kick the motor to life every time you ride it. If you explained the specifications to somebody who had never seen one before, they would probably assume the motorcycle was miserable to ride. And honestly, that is what surprises most people the first time they actually spend time around one.
Once you get a Duo-Glide out on the road, it immediately starts to feel familiar. The riding position is almost identical to a modern Harley touring bike, the big nacelle-mounted headlight cuts through the wind the same way and the weight sits low in the chassis just like a Road King or Street Glide. At highway speed, the whole motorcycle settles into a smooth rhythm that Harley-Davidson has honestly never moved very far away from. Modern touring bikes are obviously faster, smoother and stop dramatically better, but the basic experience is still there. You can ride a 1964 FLH down the highway at 60 or 65 mph and very quickly understand the direct connection between the Duo-Glide and every touring Harley that followed it.
That is really what makes the 1964 model year so important. The 1964 FLH sits right at the transition point between what most people think of as an “old motorcycle” and what would become the modern Harley-Davidson touring platform. It was the final year of the kick-only Harley-Davidson big twin and the last touring Harley that still fully operated like a machine from the prewar era. One year later the Electra-Glide arrived with electric start, a new 12-volt electrical system and a completely different ownership experience. The Panhead motor itself would survive through 1965, but by then Harley-Davidson had already started moving into a more modern era.
That makes the 1964 Duo-Glide something of a strange middle ground. It still carries all the mechanical rituals and quirks that riders had dealt with since the 1930’s, but wrapped in a motorcycle that was already beginning to resemble a modern highway touring machine.
What Does FLH Duo-Glide Actually Mean?
Before getting too deep into the history, it is worth explaining the different names attached to these motorcycles because Harley-Davidson terminology can get confusing pretty quickly if you are not familiar with it. If you look at the VIN number stamped into the left side engine case, you will find the letters “FLH” between the year and the production number. The “FL” designates a 74 cubic inch big twin motor while the “H” indicates the high-compression version of that engine. By the early 1960’s the FLH represented Harley-Davidson’s top-of-the-line touring motorcycle.
The name “Duo-Glide” refers to the chassis itself and specifically the addition of rear suspension. Harley-Davidson introduced the Duo-Glide in 1958 as the replacement for the earlier Hydra-Glide models. The Hydra-Glide, produced from 1949 through 1957, had hydraulic front forks but still used a rigid rear frame. The Duo-Glide added a swingarm rear suspension with twin shocks, making it the first Harley-Davidson big twin with both front and rear suspension from the factory. That may not sound revolutionary today, but for Harley riders in the late 1950’s it was a massive improvement in comfort and highway capability.
Before the Duo-Glide, Harley riders relied largely on a spring-loaded seat post to absorb bumps from the road. Harley-Davidson had spent decades building rigid frame motorcycles and many traditional riders were actually resistant to rear suspension at first. But by the late 1950’s America’s highway system was rapidly improving and riders were beginning to cover much longer distances at higher sustained speeds. Harley-Davidson understood that motorcycles were evolving from short-distance transportation into true long-distance touring machines and the Duo-Glide was really designed around that changing style of riding.
The final nickname attached to these motorcycles is of course “Panhead,” which is not an official Harley-Davidson designation at all. Riders simply started referring to the motor as a Panhead because the rocker covers resembled upside-down pie pans. Harley riders have always been good at assigning nicknames to engines and the Panhead followed the Knucklehead and would later be replaced by the Shovelhead.
The Evolution of the Panhead
The Panhead first appeared in 1948 and represented a major redesign over the earlier Knucklehead motor. After World War II, riders were spending far more time riding long distances and the older Knucklehead top end struggled with heat management and oil control during sustained highway use. Harley-Davidson responded with aluminum cylinder heads featuring improved cooling fins along with a redesigned oiling system intended to improve reliability and reduce operating temperatures.
Throughout the Panhead production run Harley continuously revised oil pumps, bearings and lubrication systems as horsepower increased and riders demanded better highway performance. By 1964 the Panhead had evolved into probably the most refined version Harley-Davidson ever built. These later motors used external oil lines feeding directly to the heads, commonly referred to as “outside oiler” heads, to improve top-end lubrication. They also benefitted from years of small engineering revisions that gradually improved reliability and highway performance. The result was a motorcycle that still looked mechanically primitive by modern standards, but was actually a very capable highway touring machine for its era.
Why 1964 Was the End of an Era
A lot of people assume 1965 was the major turning point because it was the final year of the Panhead motor, but in many ways 1964 is actually the more historically important bike. 1964 was the last year before Harley-Davidson introduced electric start on the big twins. That meant it was also the final year before Harley switched from a 6-volt electrical system to 12-volts. The addition of electric start required a much larger battery, a starter motor and a cast aluminum primary to house the entire system. Depending on configuration, the changes added roughly 50 pounds to the motorcycle.
Interestingly, Harley-Davidson had already experimented with electric start on the Servi-Car before bringing the system to the big twins. Harley was not necessarily opposed to electric start philosophically, but the technology simply was not ready earlier. Electric start systems capable of turning over a large displacement V-twin reliably required a stronger electrical system and more robust components than what Harley had been using previously. There were also riders who resisted the change. Kickstarting a Harley had been part of the ownership experience for generations of riders and there was definitely a feeling among some traditionalists that electric start made motorcycles softer or less mechanical. Even today, there is still something satisfying about kickstarting an old Harley in a parking lot full of electric-start motorcycles.
That old starting ritual is part of what gives a 1964 FLH such a different personality from later Harleys.
Starting a Panhead
The actual starting procedure is where most modern riders immediately realize just how different these motorcycles are from anything built today. Starting a Panhead is less about brute force and more about understanding the machine. Every rider eventually develops their own slightly different process depending on weather, engine temperature and how well the carburetor is behaving that particular day.
On my bike the process usually starts with retarding the timing, turning on the fuel, choking the carburetor and rolling the throttle wide open. Then I give the motor a couple priming kicks with the ignition off before turning on the ignition and giving it one good committed kick. If the bike is tuned correctly, it usually starts immediately. If not, you start over again.
Despite what a lot of people assume, properly tuned Panheads are usually very easy starting motorcycles. Most owners of old Harleys will tell you the same thing: the bikes generally start on the first kick or the last kick. One of the biggest misconceptions modern riders have is that you are constantly advancing and retarding the timing while riding. In reality, the manual spark advance is primarily used during starting. Once the bike is running and timed correctly, you are not constantly adjusting it going down the road.
Dual Points, 6-Volts and Other Old Harley Quirks
The ignition system used on 1961 through 1964 FLH models was another interesting oddity. Instead of a single set of breaker points, Harley used a dual-point ignition system with one set of points and one ignition coil dedicated to each cylinder. The idea was that you could tune each cylinder independently for more precise ignition timing. In reality, the system is harder to adjust than a standard single-point setup and probably offered only marginal performance improvement, which is likely why Harley used it for such a short period of time. That said, once properly adjusted, the system works perfectly fine.
The 1964 models were also the last Harley-Davidson big twins to use a 6-volt electrical system. The biggest difference between 6-volts and modern 12-volt systems is simply lighting. The headlights and running lights are noticeably dimmer than modern motorcycles, especially at idle. My own bike has been converted to 12-volts, which makes the motorcycle a little more practical in the modern world and allows small conveniences like charging a cell phone while riding. A lot of riders today make similar upgrades because they improve reliability and usability without dramatically changing the character of the motorcycle.
Riding a Duo-Glide on Modern Roads
The funny thing about a Duo-Glide is that despite all the old technology, the bike still works surprisingly well as a touring motorcycle. The FLH was absolutely designed as a highway machine. Harley-Davidson offered the bikes with windshields, hard bags, crash bars and full touring equipment from the factory. Combined with the new rear suspension introduced in 1958, the Duo-Glide became a genuinely comfortable long-distance motorcycle by the standards of the day.
That said, it was designed around the highway speeds of the early 1960’s. Modern interstate traffic moves considerably faster than what Harley engineers were expecting when these bikes were built. To reduce vibration at sustained modern highway speeds, I converted my bike from the original chain primary to a belt drive system. Little upgrades like that can make these motorcycles much more enjoyable to ride regularly without fundamentally changing what they are.
Fuel range is another reminder that this was still an early 1960’s touring machine. With the stock 3.5 gallon tanks, you are usually looking for gas every 100 miles or so. A well tuned bike will generally get over 30 miles per gallon, but this is definitely not a modern long-range touring bike. And when you are covering serious miles on a Panhead, you are expected to carry tools. At minimum you need enough tools and fluids to adjust and lubricate the chain during longer trips. Carburetors may also need minor adjustments when changing altitude, although that can actually be done while riding without tools.
This is part of the ownership experience people often do not understand today.
Riding an Old Harley Means Knowing the Machine
To successfully own and ride a motorcycle like this, you need to be mechanically inclined. There is really no way around it. Seasonally you are adjusting timing, carburetion, points, replacing spark plugs, cleaning the air filter and changing fluids. You are listening to the bike constantly and learning what sounds normal and what does not. These motorcycles are over 60 years old now and breakdowns do happen. When they do, you need to know how to troubleshoot the machine on the side of the road and fix the problem quickly.
Modern Harley dealerships generally will not work on old motorcycles anymore and the number of independent shops capable of properly servicing Panheads gets smaller every year. That means the rider becomes part mechanic whether they planned on it or not. Honestly, I think that is one reason people become so attached to old Harleys. There is a sense of satisfaction that comes from successfully riding and maintaining one that modern motorcycles simply do not really offer anymore.
Modern motorcycles are designed to isolate the rider from the mechanical experience. A Panhead does exactly the opposite. You hear the valvetrain working, feel the transmission clunk into gear and notice every movement of the throttle. The motorcycle demands participation from the rider. If you do not understand the machine, you are eventually going to spend a lot of time sitting beside the road.
Drum Brakes and Riding Technique
One area where the age of the design becomes impossible to ignore is the braking system. On the Duo-Glide, the front drum brake basically exists to hold the bike still at a stop sign on a mild hill. It provides very little actual stopping power. Almost all of the braking comes from the rear hydraulic drum brake. By modern standards, the brakes are terrible.
But context matters. In the early 1960’s, most motorcycles still used drum brakes and traffic generally moved at lower speeds. Riders adapted their riding style accordingly. You ride much farther ahead mentally on a Panhead than you do on a modern motorcycle because you have to anticipate stops long before they happen. Again, this is another area where riding an old Harley forces the rider to stay actively involved in operating the machine.
Why Panheads Became Choppers
One reason original Duo-Glides survive in greater numbers today compared to earlier rigid frame Panheads is that they were not the ideal platform for building choppers. You cannot really build a traditional chopper with rear shocks, which meant converting a Duo-Glide into a true hardtail chopper required substantial frame modifications. Earlier rigid frame Panheads were far easier to chop and customize, which is one reason relatively original rigid frame Panheads are much harder to find today.
At the same time, Panheads became hugely important to chopper culture for several reasons. First, they were the motorcycles available during the 1960’s when choppers first exploded in popularity. Second, they were more affordable and generally more dependable than Knuckleheads. Third, movies like Easy Rider permanently linked Panhead-powered motorcycles to American chopper culture in the minds of an entire generation. Ironically, that cultural connection is probably one reason relatively stock Duo-Glides are becoming increasingly appreciated today.
The Last of the Real Kick-Start Touring Harleys
One thing that still surprises modern riders is how visually similar the Duo-Glide is to a modern Road King. People will often walk up to the bike thinking it is some kind of newer Harley touring model until they notice the kicker arm hanging off the side of the transmission. Less knowledgeable people frequently misidentify the motor entirely or assume the motorcycle is wildly unreliable simply because it is old.
The reality is that a properly maintained Panhead is usually a very dependable motorcycle. But it is dependable in a very different way than a modern Harley. A modern touring bike can go thousands of miles with almost no rider involvement beyond basic maintenance. A Panhead expects the rider to understand the machine mechanically and actively participate in keeping it running correctly.
That difference is exactly what makes motorcycles like the 1964 Duo-Glide so rewarding to ride. This was the final fully developed version of Harley-Davidson’s old mechanical touring motorcycle philosophy before electric start, larger electrical systems and modern technology fundamentally changed the riding experience forever. And once you spend enough time riding one, you realize something important: the reason people still love old Harleys has very little to do with nostalgia. It is because modern motorcycles rarely require the rider to truly know the machine anymore. A 1964 Duo-Glide still does.