Google Maps Bike There…for a safer, healthier, happier world. :-)


How To Calculate the Speed of a Commuting Bicyclist

August 25, 2008 By: Peter Smith Category: Bicycle Maps

That’s not something I’ve thought too much about, but we know that BBBike does it, so presumably, if Google Maps were to provide a “Bike There” feature, they would want to provide a travel-time estimate, so they would need to be able to estimate the speed of the average bicycle commuter. Fortunately for us, Joel Fajans, a physics professor at UC-Berkeley, has done the research. He introduces his work with physics and bicycles this way:

Combining my work and hobby, I’ve spent some time investigating the physics of bicycling. Did you know that to turn a bike to the right, you actually push the handlebars to the left? And contrary to the beliefs of most physicists, the stability of a bicycle has little to do with the angular momentum in the wheels. I’ve written a nontechnical summary, and a technical tutorial paper on the bicycle steering. The calculations in the paper were done in MathCad, and can be downloaded.

A PDF version of the article is here.

We’re big on research, so it’s great to find another great source of good information.

Can’t say the “push the handlebars to the left” makes sense to me, but what do I know? I guess you push on the left side of your handlebars and pull on the right side.

From this page, we read that Melanie Curry is the managing editor of ACCESS, a transportation journal published quarterly by the University of California Transportation Center at Berkeley.

I stumbled onto the work of Fajans when doing some quick research for a post about stop sign laws.

A cycling professor, huh? Hmm. Remind you of anyone?

3 Comments to “How To Calculate the Speed of a Commuting Bicyclist”

  1. David Alpert says:

    By “push the handlebars to the left” he really does mean turning them to the left. A bicyclist actually subtly turns the handlebars the opposite direction briefly to make the bike lean in the correct direction, then turns the handlebars in the direction of the turn to stabilize.

    It’s called countersteering:

    According to the Wikipedia article, bicyclists almost do this unconsciously, while motorcyclists have to do it strongly and deliberately due to their higher speeds.

  2. Peter Smith says:

    Wow - that’s totally freaky. Thanks David!

  3. John Hopkins says:

    Countersteering is taught in the League of American Bicyclists’ safety courses as a crash-avoidance technique. You would normally make a right turn, for instance, by simply leaning to the right. But if you need to turn on a dime, that is, really sharply, as you would if a car cut in front of you at an intersection, a quick flick of the handlebars toward the left, then a lean to the right will get you into a 90-degree turn that could save your life.


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