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[[Image:Bicycle.jpg|right|thumb|300px|Modern bicycle with recommended reflectors for night riding]]

[[Image:Bicycle.jpg|right|thumb|300px|Modern bicycle with recommended reflectors for night riding]]

A '''bicycle''' is a human-powered, two-wheeled conveyance that serves as a popular means of transportation in many nations, and a form of recreation virtually world-wide. A bicycle is also known as a cycle, a bike, or a pedal cycle (this last is to distinguish it from a motorcycle).

A '''bicycle''' is a human-powered, two-wheeled conveyance that serves as a popular means of transportation in many nations, and a form of recreation virtually world-wide.  Most bicycles are propelled by pedals driven by the rider's feet. A bicycle is also known as a cycle, a bike, or a pedal cycle (this last is to distinguish it from a motorcycle).

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.

| publisher = Massachusetts Institute of Technology

| publisher = Massachusetts Institute of Technology

| isbn = 0-262-73154-1

| isbn = 0-262-73154-1

| pages = pages 342–349}}</ref>

| pages = pages 342–349}}</ref> Bicycle tires can also affect efficiency.<ref>{{cite web

==Electric bicycle==

==Electric bicycle==