These little bells, known in the motorcycling world as Gremlin Bells, Guardian Bells, or Spirit Bells, are a kind of good luck charm for motorcycle riders. The bell is said to protect them during their travels.
Legend has it that there are harmful spirits that lurk the roadways, always on the lookout for motorcycles to cling onto and cause mischief. You may have heard of unusual and hard-to-diagnose problems that occur in machines (most often in electrical systems) being called “gremlins,” and supposedly, it is these same unpredictable and harmful spirits that cause problems for motorcycles and their riders.
The Gremlin Bell is a way to ward off these spirits. It is said to work by capturing them in the hollow of the bell and infuriating them with the constant ringing until they release their hold and break free, returning to the roadway to find another unsuspecting riderwithouta bell to harass instead.