Harley Davidson Reliability: Are They Any Good?



First established in Milwaukee, Wisconsin, in 1903, Harley has a rich legacy of producing iconic motorcycles as one of the oldest American automotive manufacturers.

Not only that, Harleys are some of the most popular motorcycles in the world. The thunderous V-twin engines and classic silhouettes have infiltrated popular culture in movies, music videos, and even contemporary fashion. 

However, marketing is a powerful tool — are Harleys really all they’re cracked up to be?

Are they reliable?

Are They worth the investment?

The short answer is yes. The long answer is it’s complicated, but still yes. Don’t worry, I’ll explain. Let’s get to it. 

Harley-Davidson History and Reputation

Harley-Davidson is one of the founders of motorcycles, there at the very beginning, but that’s both a blessing and a curse. 

People love the long legacy of H-D, but a long legacy also means a lot of ups and downs — and those downs can tarnish an otherwise stellar reputation. Arguably the worst era for Harley was the late 1950s and early 1960s. 

Motorcycles were beginning to find their stride after WWII, and manufacturers were producing bigger and faster bikes. However, owners also started to work on their bikes themselves, modifying various parts to get the bikes to go faster either in races or just on the streets. 

These unqualified owners modifying their bikes without any mechanical knowledge sometimes caused serious issues. This, paired with a period of growth in which new tech and development were growing exponentially — which is always trial and error at first — meant the bikes of this period weren’t exactly reliable.

Engine issues, such as overheating, oil leaks, or extreme vibrations, as well as poor chassis construction, were pretty common. Luckily, after new investors and changes in ownership, Harley quickly began fixing the issues that plagued its post-war bikes. 

New frames, new rubber-mounted engines, and new transmissions, among many other updated designs and components, were rolled out and Harley began to gain a good reputation. 

Also around this time, Harley began setting service and maintenance schedules for their new models so owners could keep their bikes running smoothly.  

The new era for Harley peaked in the 1980s, predominantly with the release of the 1984 Evolution V-twin engine. 

Although I love my classic H-Ds, with the Ironhead Sportster being one of my favorite bikes, current riders are mostly interested in more modern bikes due to the enhanced reliability, so let’s shift to the present and Harley’s modern era — the ups, so to speak. 

Harley Engine Reliability

At the heart of any motorcycle is the engine. This tends to be the way most of us judge a bike’s reliability, and the engine can be the make or break of a good bike. 

When it comes to modern Harley-Davidson motorcycles, there are a few engines we’re talking about: Evolution, Twin Cam, Milwaukee-Eight, Revolution, Revolution X, and Revolution Max. 

Evolution and Twin Cam Engines

The Evo engine is known for its reliability. It’s a solid unit that was extremely popular upon its release and subsequently in all of its displacements in different models. 

The Evo was produced specifically to improve performance and reliability, receiving enhanced features, such as aluminum cylinders and heads. 

However, the motor did suffer from a few issues, such as overheating, low oil pressure, power loss, and issues with the cam chain tensioner. 

Overheating is a common problem across the board with all air-cooled engines, so this isn’t really a deal breaker, and the other problems with the Evo engine were all fairly simple and affordable to resolve. 

In fact, many Evo-powered bikes have reportedly seen in excess of 100,000 miles and are still ready and willing to crunch some more. 

The Twin Cam engine, also produced to improve performance and reliability, is another popular choice for Harley riders. The Twin Cam suffered from a few teething issues, particularly early on, for instance, crank issues and cam chain tensioners that were significantly below par. 

However, the majority of these problems were resolved by 2007, so bikes that came after that are relatively problem-free. 

Like the Evolution, Twin Cam engines will easily hit 100,000 miles and beyond.  

Milwaukee-Eight Engines

The Milwaukee-Eight took over where the Twin Cam left off. Performance and reliability greatly improved with the release of the Milwaukee-Eight, and all the big twin models are currently powered by the Milwaukee-Eight engine. 

The M8 has better airflow and more valves, and it produces more power and better fuel efficiency. However, just like when the Twin Cam was introduced, the early M8 bikes suffered from teething problems, so to avoid these, choose a bike from 2019 or later. 

Revolution Engines

Revolution engines were first introduced with the Harley-Davidson V-Rod, a model that had been worked on in conjunction with Porsche. 

To start off, it was a liquid-cooled engine, which drastically strayed from traditional air-cooled twins, and the focus was on raw power above anything else. 

While the V-Rod is a divisive motorcycle, the engine was never the issue. It actually proved to be quite powerful and reliable. 

Later on, the Revolution X was produced for the Street range, a series of small-capacity Harleys with liquid-cooled engines, to attract new riders. These, too, weren’t popular with Harley traditionalists, but the engines again proved to be solid and reliable, with no major problems. 

Most recently, we’ve seen the arrival of the Revolution Max, a liquid-cooled powerhouse that is equipped in the Pan-America, Sportster S, and Nightster. It is perhaps too soon to comment on the long-lasting durability of the Revolution Max, but there don’t appear to have been any early problems with the motors. 

Overall, modern Harley engines are solid, reliable, and long lasting. Stick to your service intervals and regular maintenance and you should be trouble-free. 

Harley Chassis Reliability

When it comes to its chassis and components, Harley has rarely let its owners down. Strong, durable frames support big, heavy engines. They’re sturdy, rigid, and even agile if you tend to get a bit sporty on your cruiser. 

There may have been the odd model run where things weren’t quite designed right, but certainly nothing notable that affected a significant number of riders. 

Maintenance and Owner Responsibility

The absolute key to motorcycle reliability is how responsible you are as the owner. Service schedules are there for a reason, an owner’s manual is there to be read, and basic maintenance is essential — this applies to all motorcycles, not just Harleys.

Generally, H-D motorcycles are fairly exposed to the elements, with a lot of raw metal parts on display. Rust, therefore, is a common problem. However, a simple remedy of regular cleaning and a protective spray can sort and prevent this easily. 

Regular air filter and oil changes are essential to ensuring your engine has a long life, trouble-free. 

Issues arise from owners not properly taking care of their motorcycles, and, unfortunately, the blame often unfairly falls on the manufacturer. If owners take responsibility for their bikes, it will save a lot of stress and expense down the line. 

Sales and Popularity

A manufacturer’s reputation is often reflected in its sales. If a motorcycle brand is producing rubbish bikes and therefore gets a rubbish reputation, sales will naturally decline. 

Harley-Davidson, however, has a positive outlook, seeing a 3% increase in motorcycle sales in the second quarter of 2023 and retail performance that’s up by 1%.

The company continues to be one of the biggest motorcycle manufacturers in the world and despite the current economic situation, H-D is booming and bouncing back after a tough couple of years. 

There are rumors that smaller-capacity bikes are on their way, certainly for the Asian markets and Europe, and further rumors of more liquid-cooled models on the way too.

H-D remains an ever-present company in popular culture (actor Jason Momoa has even recently collaborated with the brand on a clothing campaign). 

It really is simple: If the bikes were trash, Harley wouldn’t be navigating the troubled economic seas as well as it is.

Verdict: Are Harleys Reliable?

So, yes, Harleys are reliable. They’re good bikes, well made, with long-lasting engines. 

There are exceptions to every rule, and certain models or years are more troublesome than others, but on the whole, any modern Harley will serve its owner well, providing it is looked after in the way it demands and deserves.