| A bicycle, also known as a bike or a pushbike, is a | | | | motion. The pedals are connected to the wheels by an |
| vehicle that has two wheels and is propelled by pedals. | | | | iron chain. A steering rod helps to keep the bike |
| Bicycles can be dated back to 19th century Europe, | | | | balanced. The main parts in a bicycle are the main |
| and have evolved gradually into several designs and | | | | frame, the drive train, steering rod, the seat/seats, |
| models available today. Bicycles are an ideal means of | | | | brakes, and optional gears. |
| transport--non-polluting, quiet, small, easy to maneuver, | | | | Bicycles can be categorized into many kinds based on |
| light and inexpensive. They can be used by anyone, | | | | the function (mountain bikes, racing bikes, messenger |
| from a 5-year-old to a 70-year-old. Bicycling is also a | | | | bikes, touring bikes, utility bikes, and Randonneu or |
| very good form of exercise. However, there are a | | | | Audax bikes), number of riders (tandem/twin, triplet |
| few disadvantages of bicycles: they cannot be used | | | | bikes and multi bikes), construction (penny farthing, |
| for great distances and they also tire out the rider | | | | upright, recumbent, folding, moulton, exercise), gearing |
| after sometime. This is the reason for the evolution of | | | | (internal hub gearing, shaft-driven bicycles, single-speed |
| the engine-powered bicycle or motor bicycle. Bicycles | | | | fixed gear, retro-direct, and Derailleur gear Bicycles), |
| are still being used a chief means of transport in most | | | | sport (track, time trial, cyclo-cross, BMX, Triathlon etc), |
| countries. There are also some jobs where | | | | means of propulsion (pedal, rowing, hand-cranked, |
| employees depend on bicycles, like postal services, | | | | motorized, shaft-driven, flywheel etc), and several |
| police services or retail delivery. | | | | other types, like cruiser bikes, freight bikes, cycle |
| A bicycle works on the simple mechanism of pushing | | | | rickshaws, clown bikes, velomobiles/bicycle cars, hybrid |
| the wheels forward by driving the pedals in a circular | | | | bikes, art bikes, unicycle and so on. |