Dirtbike

There are many systems for classifying types of motorcycles, describing how the motorcycles are put to use, or the designer's intent, or some combination of the two. Six main categories are widely recognized: cruiser, sport, touring, standard, dual-purpose, and dirt bike. Sometimes sport touring motorcycles are recognized as a seventh category. Strong lines are sometimes drawn between motorcycles and their smaller cousins, mopeds, scooters, and underbones, but other classification schemes include these as types of motorcycles.

There is no universal system for classifying all types of motorcycles. There are strict classification systems enforced by competitive motorcycle sport sanctioning bodies, or legal definitions of a motorcycle established by certain legal jurisdictions for motorcycle registration, emissions, road traffic safety rules or motorcyclist licensing. There are also informal classifications or nicknames used by manufacturers, riders, and the motorcycling media. Some experts do not recognize sub-types, like naked bike, that "purport to be classified" outside the six usual classes, because they fit within one of the main types and are recognizable only by cosmetic changes.

Street motorcycles are motorcycles designed for being ridden on paved roads. They have smooth tires with a light tread pattern and engines generally in the 125 cc (7.6 cu in) and over range. Most are capable of speeds up to 100 mph (160 km/h), and many of speeds in excess of 125 mph (201 km/h).

Standards, also called naked bikes or roadsters, are versatile, general-purpose street motorcycles. They are recognized primarily by their upright riding position, partway between the reclining rider posture of the cruisers and the forward leaning sport bikes. Footpegs are below the rider and handlebars are high enough to not force the rider to reach far forward, placing the shoulders above the hips in a natural position. Because of their flexibility, lower costs and their engines of moderate output, standards are particularly suited to motorcycle beginners.

Standards usually do not come with fairings or windscreens, or if they have them, they are relatively small. Standard is often a synonym for naked bike, a term that became popular in the 1990s in response to the proliferation of fully faired sport bikes. The standard seemed to have disappeared, fueling nostalgia for the return of the Universal Japanese Motorcycle, which were admired for their simplicity, quality, and versatility.

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