Tech & Auto
This Is What Really Creates That Unique Harley-Davidson Sound
By ETHAN ZACK
Harley-Davidson motorcycles have long been known for their trademark sound — a sort of fast-paced, rhythmic clicking that follows a repeating "beat-beat-pause" pattern.
The distinctive sound is no accident, as Harley-Davidson engines feature configurations that differ from other bikes on the market in some key regards.
Similar to the standard structure of a two-cylinder motorcycle engine, Harley-Davidson engines contain two pistons, but they do not fire at fixed intervals.
There is also only one pin for both pistons and its spark plugs are positioned at a 45-degree angle. As a result, the two pistons have to wait for uneven intervals of time to fire.
The first two beats are the two pistons firing in quick succession, while the pause comes from the comparatively longer amount of time it takes for the first piston to start again.