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A real bike that you ride (BMX styles with 8-8.5" petals)

2006-10-24 06:55:19 · 6 answers · asked by S--slick 4 in Science & Mathematics Physics

6 answers

Most fit adults can produce 100 watts (0.134 horsepower) of mechanical power on a bicycle for a sustained period. A world-class competitive cyclist can produce up to 500 watts (0.67 horsepower) over a sustained period of time.

The human power measure of 1/10 of a horsepower got into science textbooks nearly a century ago and just never was corrected.

- engineer and cyclist

2006-10-24 07:29:56 · answer #1 · answered by Deep Thought 5 · 1 0

To help sell his steam engines, Watt needed a way of rating their capabilities. The engines were replacing horses, the usual source of industrial power of the day. The typical horse, attached to a mill that grinded corn or cut wood, walked a 24 foot diameter (about 75.4 feet circumference) circle. Watt calculated that the horse pulled with a force of 180 pounds, although how he came up with the figure is not known. Watt observed that a horse typically made 144 trips around the circle in an hour, or about 2.4 per minute. This meant that the horse traveled at a speed of 180.96 feet per minute. Watt rounded off the speed to 181 feet per minute and multiplied that by the 180 pounds of force the horse pulled (181 x 180) and came up with 32,580 ft.-lbs./minute. That was rounded off to 33,000 ft.-lbs./minute, the figure we use today.

Put into perspective, a healthy human can sustain about 0.1 horsepower. Most observers familiar with horses and their capabilities estimate that Watt was a bit optimistic; few horses could maintain that effort for long.

2006-10-24 07:01:20 · answer #2 · answered by Nick W 3 · 1 0

More than a hp for a short time. If you went up a stairs 4 steps in a second it would be 3/4 hp

2006-10-24 07:05:53 · answer #3 · answered by jekin 5 · 0 0

M.B. is correct. Fit adults can produce about 1/10 HP, and top cyclists can get 1/4 HP but only for short burst.

(It is called HORSE power for a reason...)

2006-10-24 07:06:03 · answer #4 · answered by Vincent G 7 · 1 0

No way. The best you could do is 1/10 of one horsepower.

2006-10-24 06:57:28 · answer #5 · answered by M.B. 4 · 0 0

Only with substancial gearing mechinisms.

2006-10-24 07:06:24 · answer #6 · answered by Anonymous · 0 2

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