| You are looking at one of the fastests bicycles in the world, the Cheetah. It weighs only 30 pounds, and set the world speed record in 1992... with a speed of 69 miles per hour, or 111 km/h! |
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The Cheetah was built by students at the University of California. Its carbon-fibre shell, called a fairing, cuts down wind resistance; it's nine feet long, but only 18 inches wide! There are no holes in it for the driver to put his feet on the ground; the bike must be held up by bystanders before starting, and supported when it stops, or it will fall over. |
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The driver sits with his legs up, as shown above. This is a trade-off; maximum pedalling power would be achieved if the pedals were lower, but this would mean the driver, sitting up, would create too much wind resistance. The least wind drag could be achieved if he were lying down, but for peak performance, the driver's heart must be above his legs. The compromise shown above seemed to work just fine, especially when combined with the extra gear assembly in the middle, which is the equivalent on an ordinary bike of a a front gear twice as wide as normal! |