| A bicycle is a simple, machine, but it | | | | Multiple gears on a bicycle helps change |
| involves a lot of mechanization. A | | | | the distance the bicycle moves forward |
| bicycle is made up of many parts put | | | | with each stroke of the pedal. A |
| together. Perfect synchronization in the | | | | mountain bike has 24 gears. Chain wheels |
| functioning of all the parts is | | | | are the gears at the front. Most bikes |
| essential for the efficient working of | | | | have 2-3 chain wheels. The freewheel, at |
| the bicycle. Modern day bicycles include | | | | the rear, has 5-9 gears on it. It spins |
| many new elements, but a standard | | | | freely in one direction and locks in the |
| bicycle has the same main parts. The | | | | other. This enables the bike to coast, |
| basic parts of a bicycle comprise; the | | | | when not pedaling. There are front and |
| frame: A bicycle's frame is made up of | | | | rear derailleurs to change the gears. |
| many tubes welded together. The front | | | | Ball bearings in a bicycle serve to |
| fork holds the front wheel and is | | | | reduce friction. Ball bearings are found |
| movable. | | | | in the front and rear hubs for the |
| The wheels: wheels include a hub, the | | | | wheels, the pedals, the fork tube, the |
| spokes, metal rim and rubber tyres. The | | | | bottom bracket and in the freewheel. |
| brakes: they include the actuators on | | | | These bearings need to be periodically |
| the handlebar, brake cables, brake pads | | | | cleaned and greased. Expensive bicycles |
| and calipers. The chain and gears: they | | | | have sealed bearing cartridges that |
| consist of the front chain wheels, the | | | | don't need lubrication. |
| rear freewheel, the shift levers on the | | | | Materials used |
| handlebars and the cables. Other bicycle | | | | Bicycles need to be strong and |
| parts include the seat, seat posts, | | | | lightweight. Alloy steel is used for |
| handlebars, handlebar stem, bicycle | | | | making the frames and fork tubes. The |
| lights, dynamos, cranks, and pedals. | | | | handlebars, seat posts and brake levers |
| Gears and ball bearings | | | | are made of aluminum alloy. Aluminum |
| Most racing bicycles have gears. Gears | | | | alloy frames are affordable. Carbon |
| basically serve the purpose of reducing | | | | frames, titanium and advanced steel |
| the size and diameter of the wheel. | | | | alloys frames are also available. |
| Gears adjust the direction of rotation. | | | | |