Electronic Design

What's All This Bicycle Stuff, Anyhow?

A friend wrote to me that flying a plane is like riding a bicycle. It took me about four seconds to rebut him: “No, flying a plane may be a little similar, but it’s much different from riding a bike.” A plane can fly fairly stably with no controls. But a bicycle has to be steered and controlled so it doesn't fall over.

And there's a big difference between flying a plane and riding a bike (or motorcycle): If you want a plane to turn, you can quickly start banking and turning. But to get a bicycle to turn left, you first have to turn the handlebars to the right and wait for the bicycle to lean to the left. After that, you can start turning left. Motorcycle riders can maneuver faster than cars, but only if they know what's coming. Drivers in cars can make unplanned maneuvers faster than cyclists.

It's amazing that so many kids learn how to ride a bicycle. It really is tricky. After learning to ride a bike, driving a car is easy. That reminds me of some of the early work of George A. Philbrick. It must have been about 1942, when the war preparations were ramping up.

George got involved in training anti-aircraft gunners. He showed that it was quite hard to learn to aim a gun with an extra lag inserted in the aiming mechanism. But after the gunner learned how to handle that lag, he became a much better gunner once the lag was removed. So that was put into gunners' training.

Well, riding a bike doesn't exactly have a lag. But it does involve a challenging problem—having to steer left before you can turn right! That's counter-intuitive. After a kid has learned to deal with that, driving a car is easy. As I've said, I wouldn't want to teach a kid to drive a car if he hadn't already learned to be a good bicyclist.

I like many things about my new mountain bike, a Specialized Rockhopper A1FS. But I can't ride it no-hands. It really has no stability for that. I'm not sure if its good maneuverability is because of this instability or in spite of it. But since I don't need to ride no-hands, I don't complain much. But I have ridden many miles no-hands on other bikes.

Of course, one operating mode is worse than not using your hands: If you cross your arms on the handlebars, you will quickly crash. So don't do it! If you just touch a finger to the handlebars and think hard, you might be able to avoid crashing, but be careful. Assume you will crash anyway.

THE GREAT SKID DEBATE
The recent debate over whether or not the better tires should be put on the front or the rear of the car has been settled in favor of the rear. That's

because skidding with the rear wheels is so "dangerous." Yet we all remember riding our bikes down a slope, locking up the coaster brake, sliding the rear wheel stably, and steering just fine!

Remember to steer in the direction of the skid. So, rear-wheel skids aren't so bad if we think about it and can steer quickly. Just don't overdo it and rip up your tires—or your father's lawn.

Our bicycle trek around the Annapurnas in Nepal (never higher than 17,771 feet) scheduled for last June had to be postponed. All five of us (even the sherpa) had too much work and couldn't get the time off. We'll try again in May 2007. Check out www.national.com/rap/nepal/index.html sections 13, 14, and 15 if you're interested in joining us.

Comments invited! [email protected] —or: Mail Stop D2597A, National Semiconductor P.O. Box 58090, Santa Clara, CA 95052-8090

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TAGS: Components
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