I occasionally talk a big game in the various social media sites, but I’m generally a pussycat on the road and big believer in cooperating with other traffic when I’m on my bike. I’m assertive about my road rights, but I won’t be a complete jackass just to make a point.
Hence, I’m not a fan of loud horns on bikes. You can reach for your brakes and come to a stop faster than you can punch a horn button, and I really dislike noise pollution.
I realize, however, that horns are popular for numerous reasons. I can recommend the Delta Cycle Airzound Horn – it’s loud and reasonably inexpensive. You charge it with an airpump. It’s made of cheap plastic bits that can (and do) fail, but they’re easily fixable.
Jonathan Lansey in Boston, however, wanted something more like a car horn with its discordant two tone *honk*, so he recruited some engineering help to create a small, lightweight electric horn for his bicycle.
There are some admirable design elements in this horn: the button is designed so you can brake while honking, for example. A single charge of the lithium battery should last for a month or two. And it sounds like a car horn.
You can buy this horn by supporting the Kickstarter project, which only has three days to go and has already met its $43,000 funding goal.
More info at LoudBicycle.com.