The Speed of Sound on a Wet Morning in Connecticut


Yesterday, I was going to write about the speed of sound but got distracted, so today I return to my regularly scheduled blogging.  What’s that thing in the photo above?

Macro level:  It’s a view of a rainy plaza and parking lot in with my bike resting against the window in the foreground.

Less-Macro “What I Care About” level:  It’s my bike.

“Important for Purposes of this Blog” level:  It’s a bell.

Here’s what it looks like when it’s not on my bike:


Well, that’s what it used to look like, before it acquired a patina.  It’s now more of a dull bronze color with a few greenish areas.

That’s fine, because it doesn’t affect the point of the bell.

Here’s the point.  Bicycles can travel pretty fast.  The fastest I’ve ever gone was 53.3 MPH (about 85 KmPH).  That’s fast.  I very rarely break 50 these days (especially now that I’ve broken 50) but routinely find myself doing 30-40 on hills and 16-20 on flats (when solo).

Given that my bike and I together total around 230#, I bet even on the flats I could do a lot of damage to myself if, say, I stopped very, very fast.  Or to myself and someone else if I was stopped very, very fast.

Fortunately, there are bells. 

Here’s the cool thing about a bell:  It sends a signal that travels at a gazillion miles per hour.  OK, not quite.  At sea level (pretty close to where I live) that signal travels at 767 MPH, or about 340 meters per second. 

Suppose you’re on a multi-use trail, traveling at 16 MPH.  You round a curve and see ahead of you a bunch of walkers happily spread out across the trail, their backs to you.  If you have a good loud bell, you can tap it to let them know your coming.  Better still, double tap it.  The space you travel over a matter of seconds in between the taps means that there will be a detectable difference in volume, all things considered, between the rings.  This may penetrate the ears of the walkers and let them know that something is coming.

Or it may not.  We live in an age of distractions–MP3 players, cell phones, trees, sky, other people. 

But it’s an improvement.  That signal travels way faster than you can on a bike.  And it’s less ambiguous than the common “ON YER LEFT!!!” (Seriously.  A pedestrian hears that.  Turns around to see you.  Tries to figure out what their left is.  Fails miserably (Side note–a friend of mine just walked into the Panera where I’m writing this and I asked him–as a pedestrian–what he thinks when he hears ‘on your left’–and he told me that he becomes confused.)).  

And–if it’s done right–it makes people smile.

How’s that?

It makes people smile because it’s courteous.  I’ve never had anyone become angry because I hit my bell a couple hundred feet or so back.  At that distance, it’s a gentle reminder (at most speeds) that someone is coming and that you need to cede space. It’s not jarring or threatening.  It is jarring if you wait until you’re 10 feet away, so don’t wait.  

People will thank you.  Literally. Don’t forget to thank them for moving over.

Oh, and there’s another reason to use a bell.  One of the great dangers cyclists face on roads is the driver about to pull out into traffic.  You’re not the kind of thing they’re looking for, and they won’t see you.  Sounding off when you see someone about to pull out can make a difference.  A good bell is audible even through a car window.

Finally, some thoughts on types of bells:

The “dragging chain” rotary type bell (the one you think of when you think of an English 3-speed) is great if your main concern is pedestrians, but less good if you’re going to try to signal cars.  A tiny “ping” bell may be aero and light, but it’s good for nothing if people can’t hear it.  In my experience, brass is way better than aluminum for resonance and, frankly, a heavier bell is a better bell.  I like the kind with a  spring-loaded striker because it doesn’t rattle when it’s not needed and it feels like I’m actually dispatching a signal, but that’s purely psychological–though these kinds of bells (as shown above) have the advantage that you can adjust how loud your signal is by varying your pull on the striker.

So:  Ring > Ping; Brass > Aluminum; Big > Little.  Make the speed of sound work for you.


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One Response to The Speed of Sound on a Wet Morning in Connecticut

  1. velomonkey says:

    well said!!!!!!

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