Did Harley Davidson Trademark Its Sound? The Real Story

Harley-Davidson V-twin engine producing the potato potato sound

If you’ve spent any time around motorcycles, you’ve heard the sound. Riders nickname it “potato potato potato” — that uneven, lumpy idle that, even from a block away, makes you turn your head and think, that’s a Harley.

The sound is so distinctive that the internet is full of confident-sounding claims that Harley-Davidson owns it — that the company holds a sound trademark on it, that other manufacturers can’t legally copy it. The truth is the opposite. Harley tried, fought for six years, and walked away. Here’s the actual story behind the most unusual trademark dispute in motorcycle history.

What Exactly Is the “Potato Potato” Sound?

Idle a Harley V-twin and you don’t get a steady, even beat. You get something that almost limps — a syncopated thud that English-speaking riders mimic by saying “potato — potato — potato,” and the nickname stuck. Where most other V-twins put out a smooth, regular pulse, Harley’s idle has a rhythm of its own.

The catch — and the reason this whole story exists — is that the sound isn’t really a design choice. It’s a mechanical inevitability.

Why It Sounds That Way: 45° V-Twin + Single Crankpin

Harley’s engine has carried two structural traits since 1909. First, the two cylinders sit in a V at exactly 45 degrees. Second, both connecting rods share a single crankpin on the crankshaft.

Harley-Davidson V-twin 45-degree single crankpin firing interval diagram — 315 and 405 degree uneven intervals across two crankshaft revolutions of a four-stroke cycle

Combine those two and even firing intervals become impossible. After the first cylinder fires, the crankshaft rotates 315 degrees before the second cylinder fires. Then there’s a long 405-degree gap before the first cylinder comes around again. Add them up — 315 + 405 — and you get 720 degrees, which is two crankshaft revolutions and equals one complete four-stroke cycle. That uneven “thud-thud — pause — thud-thud — pause” rhythm is what you’re hearing.

Here’s the crucial point. This sound isn’t something Harley designed in. It’s something that falls out automatically from this architecture. Any engine built this way produces a sound in the same family. That fact would become the decisive issue in the trademark fight.

1994: Harley’s Bid to Own a Sound

On February 1, 1994, Harley-Davidson filed an unusual application with the U.S. Patent and Trademark Office. They weren’t trying to register a logo or a slogan — they wanted to register the exhaust sound itself as a sound mark. The wording on the filing went like this:

“The mark consists of the exhaust sound of applicant’s motorcycles, produced by V-twin, common crankpin motorcycle engines when the goods are in use.”

Sound marks weren’t unheard of. MGM’s lion roar, Intel’s chime — short audio signatures had been registered before. But registering the full exhaust note of a motorcycle engine had no real precedent. In the 1990s U.S. market, Harley was going head-to-head with Japanese “metric cruisers,” and locking down their signature sound by law would have been a powerful competitive moat.

USPTO sound trademark application document — Harley-Davidson 1994 filing for V-twin common crankpin exhaust sound

Six Years of Dispute — Then a Withdrawal

The pushback was immediate. Nine competitors — Honda, Yamaha, Suzuki, Kawasaki, and others — filed oppositions, and their argument was both simple and devastating.

That sound isn’t unique to Harley. Any engine with the same 45° V-twin and single-crankpin architecture, regardless of manufacturer, produces a similar sound. It’s not a design feature — it’s a mechanical byproduct of the engineering.

The Functionality Doctrine

This argument hit the legal heart of the case. Trademark law has something called the functionality doctrine. Trademarks exist to protect signs that identify the source of a product. They are not meant to protect features that automatically result from how a product works. If a feature is essential to the use or purpose of the product, no single company gets to monopolize it. Otherwise, one company could fence off a whole category of engineering. Had Harley’s trademark been granted, competitors building similar V-twins would have had to redesign their engines or pay licensing fees — for a sound that physics, not Milwaukee, was making.

Japanese V-twin cruisers from Honda Yamaha Suzuki Kawasaki — competitors who opposed Harley sound trademark

The opposition dragged on for six years with no resolution in sight. In early 2000, Harley-Davidson finally withdrew the application themselves. The most-loved exhaust note in a generation of motorcycling had failed to win legal status as the property of one company.

So Where Does That Leave Things?

This is where the story gets interesting. Legally, no single company can claim that sound. In the marketplace, though, “the Harley sound” still belongs to Harley in every way that matters. Any V-twin can put out that beat now, but riders still hear the lumpy idle and think Harley first. Six years of public dispute turned into six years of free advertising.

The company’s then-Vice President Joanne Bischmann put a perfect bow on the whole affair, telling the Los Angeles Times in 2000: “If our customers know the sound cannot be imitated, that’s good enough for me and for Harley-Davidson.” They didn’t get the legal right. They already had the one inside the customer’s head.

Final Thoughts

What to Remember About the Harley Davidson Sound Trademark

The Harley Davidson sound trademark story is a rare real-world test of a strange question: can you own a sound? The legal answer was no. The 1994 application ended with the 2000 withdrawal, and no federal U.S. trademark protects that exhaust note today.

But in the minds of riders, Harley won. The uneven thud still makes people think of Harley first, and any other manufacturer who comes close gets compared to it. Maybe the strongest trademark isn’t the one written into the registry — it’s the one written into people’s ears.