A motorcycle is a powered two-wheeler that has an engine as its primary source of power. Typically, the term refers to an internal combustion engine that is capable of producing thrust at the rear wheel through the crankcase. The power from the engine is delivered via a clutch that engages with the transmission and allows the gears to propel the bike forward at different speeds.
A variety of chassis designs are available to suit the needs of various riders. The most common frames are constructed of tubular and/or rectangular sections of steel, though carbon fiber and composites are becoming more prevalent as they offer higher strength-to-weight ratios. The frame supports the engine, rider and passenger. A steering system is also commonly used to control the motorcycle.
Suspension systems consist of front and/or rear hydraulic shocks that cushion impacts with the road to provide a smooth ride. Motorcycle wheels are smaller and rounded to permit leaning while turning, which aids in maneuverability.
Many countries have laws to protect riders and others on the road. Motorcyclists are encouraged to wear protective gear, including leather clothing and riding gloves, and to carry a helmet that meets minimum standards set by the government. In addition, many states have enacted laws requiring helmets for all riders regardless of their age or experience level.
In recent years, gas prices have driven a boom in interest for motorcycles as an economical mode of transportation. Discounted tolls, free parking and HOV lanes for motorcycles may help further drive this trend. However, the large number of inexperienced and untrained drivers on motorcycles continue to pose a significant safety risk for themselves and other roadway users.
