Classic Harley Davidson motorcycles are known for their distinctive sound, often referred to as the "Harley rumble." The noise level of a classic Harley Davidson can be quite loud compared to other motorcycles of its era. This is primarily due to the design of the engine, which typically features large displacement V-twin engines with long stroke lengths and heavy flywheels.
The exhaust system on a classic Harley Davidson is also designed to enhance the engine's sound, with aftermarket options available to further amplify the noise. These factors contribute to the characteristic deep, throaty exhaust note that Harley Davidsons are famous for.
In comparison to other motorcycles of its era, such as Japanese or European bikes, classic Harley Davidsons generally produce a louder noise. This is partly due to differences in engine design and configuration. While some motorcycles prioritize high-revving performance with smaller engines, Harley Davidsons are known for their torquey, low-end power delivery, which contributes to the distinct sound they produce.
Additionally, modern Harley Davidson motorcycles have made efforts to meet stricter noise regulations, so the noise levels of newer models may differ from classic ones.