There are loads of reasons why the Harley-Davidson brand and the motorcycles it's recognized for around the world are so iconic. Its bikes — yes, even the Harley models we love to hate — bear a distinct look to help them stand out from the competition, the logo is instantly recognizable, and the level of community surrounding these motorcycles is second to none. Not to mention, there's also that distinct Harley-Davidson sound that emanates from its bikes. If you've spent any time around them, odds are you know that signature idle rumble very well. Fully aware of this phenomena, the company attempted to trademark the sound some years ago, albeit with no success.