"Chris W" wrote in message
...
Answer this.....

First some background. For times of bad weather they make a device you
can put your bicycle on to "train" indoors called "Rollers" They consist
of three rollers about 18 to 24 inches long, 2 are close together and the
back wheel rests between them the third is positioned under the front
wheel. See photo here....
http://www.nashbar.com/nashbar_photos/medium/TX-SPT.gif

In this situation the bicycle is obviously not moving forward. How does
it stay upright?


A bicycle is an open loop unstable "plant" that is stabilized by an organic
neural net closed loop controller.

Some aircraft are like that too. e.g. taildraggers on the ground. (how's
that for an attempt to drag this back to an aviation related thread?)

--
Geoff
The Sea Hawk at Wow Way d0t Com
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