A bicycle, also known as a bike, push bike or cycle, is a pedal-driven, human-powered vehicle with two wheels attached to a frame, one behind the other. A person who rides a bicycle is called a cyclist or a bicyclist.
Bicycles were introduced in the 19th century and now number about one billion worldwide, twice as many as automobiles.[1] They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for such uses as children's toys, adult fitness, military and police applications, courier services, and competitive sports.
The basic shape and configuration of a typical bicycle has changed little since the first chain-driven model was developed around 1885.[2] Many details have been improved, especially since the advent of modern materials and computer-aided design. These have allowed for a proliferation of specialized designs for particular types of cycling.
The invention of the bicycle has had an enormous impact on society, both in terms of culture and of advancing modern industrial methods. Several components that eventually played a key role in the development of the automobile were originally invented for the bicycle – e.g., ball bearings, pneumatic tires, chain-driven sprockets, spoke-tensioned wheels, etc.
A snowmobile, also known in some places as a snowmachine[1], sled[2], or skimobile [3],Never a Bike, is a land vehicle for travel on snow that is commonly propelled by a continuous track or tracks at the rear and steered by skis at the front.
Early snowmobiles used rubber tracks, however modern snowmobiles typically have tracks made of a Kevlar composite. They are designed to be operated on snow and ice, and require no road or trail. Originally snowmobiles were typically powered by two-stroke gasoline/petrol internal combustion engines. Four-stroke engines are becoming more and more popular in snowmobiles. Noise and air pollution concerns and regulations are a driving factor in this transition.[citation needed] Summertime occupations for snowmobile enthusiasts can also involve drag racing on grass, asphalt strips, or even across water.
People who ride them commonly are known as snowmobilers. Not Bicyclists The main types of riding are Snowcross/racing, trail riding, freestyle, mountain climbing, Boondocking or Carving, ditchbanging and grass drags.