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Line 5: − The bicycle has been called the most energy-efficient means of transport yet devised, with over 90 percent of the cyclist's power effectively applied to turning the wheels.+ + + + + + + + + + + + + +
add references re efficiency
The first recorded "two-wheeler" was the "draisine" designed in 18th century Germany by Baron Karl von Drais, possibly for use in traveling his estate to collect rents from his tenants. Decades later, Scottish blacksmith Kirkpatrick MacMillan added a pedal and chain drive mechanism to create the most credible prototype of the modern bicycle. Subsequent improvements included Englishman J.K. Starley's now-familiar diamond-shaped frame, Dunlop's pneumatic tire, multiple-gear options, and increasingly sophisticated brakes. The basic design of bicycles was relatively unchanged through the first half of the 20th century, but many subtypes of bicycles have subsequently evolved, including the [[racing bike]], [[road bike]] and [[mountain bike]], to suit the needs of specific cyclists.
The first recorded "two-wheeler" was the "draisine" designed in 18th century Germany by Baron Karl von Drais, possibly for use in traveling his estate to collect rents from his tenants. Decades later, Scottish blacksmith Kirkpatrick MacMillan added a pedal and chain drive mechanism to create the most credible prototype of the modern bicycle. Subsequent improvements included Englishman J.K. Starley's now-familiar diamond-shaped frame, Dunlop's pneumatic tire, multiple-gear options, and increasingly sophisticated brakes. The basic design of bicycles was relatively unchanged through the first half of the 20th century, but many subtypes of bicycles have subsequently evolved, including the [[racing bike]], [[road bike]] and [[mountain bike]], to suit the needs of specific cyclists.
A bicycle can be a very energy-efficient means of transport. A well-maintained chain-driven bicycle can achieve efficiencies of over 98%, though the use of gearing mechanisms may reduce this to as low as 80% in some gears, with hub gears being generally a little less efficient than derailleur gears.<ref>
[http://www.jhu.edu/~gazette/1999/aug3099/30pedal.html "Johns Hopkins Gazette"],
30 August 1999</ref><ref>{{cite book
| title = Bicycling Science
| edition = Third edition
| last = Wilson
| first = David G.
| coauthors = J Papadopuolos
| year = 2004
| publisher = Massachusetts Institute of Technology
| isbn = 0-262-73154-1
| pages = pages 342–349}}</ref>
==Electric bicycle==
==Electric bicycle==
An '''electric bicycle''' provides power assistance to a [[bicycle]] rider, by use of a battery-powered [[electric]] motor. The motor is much quieter than an engine, and when mounted in the hub of a wheel it looks like a big drum brake.
An '''electric bicycle''' provides power assistance to a [[bicycle]] rider, by use of a battery-powered [[electric]] motor. The motor is much quieter than an engine, and when mounted in the hub of a wheel it looks like a big drum brake.
==References==
<references/>
[[Category:Sports]]
[[Category:Sports]]
[[Category:Technology]]
[[Category:Technology]]
[[Category:Transportation]]
[[Category:Transportation]]