In case any of us have forgotten, bells are a courtesy to your fellow cyclists and path users. Hearing a ding over your shoulder is a universal signal to move over. It's everything a car horn can never be, unoffensive yet purposeful.  If you're like me you are in the habit of saying "Left" or "On your left" a moment before passing. In many cases I would like to give my warning earlier but I don't want to ride around yelling at people from 30 feet back.  I don't like to give the impression I'm in a panic so I wait until I'm in ear shot and try to speak in a normal tone that won't startle my fellow rider.  We all try to be careful, but the fact is there isn't a common understanding among cyclists of how we are meant to signal each other on the road. The Spurcycle bell is an elegant solution and having a bell that functions this well is a favor to everyone.