A sport bike, sports motorcycle, or sports bike is a motorcycle designed and optimized for speed, acceleration, braking, and cornering on asphalt concrete race tracks and roads. They are mainly designed for performance at the expense of comfort, fuel economy, safety, noise reduction and storage in comparison with other motorcycles.
Sport bikes can be and are typically equipped with fairings and a windscreen to deflect wind from the rider to improve aerodynamics.
Soichiro Honda wrote in the owner's manual of the 1959 Honda CB92 Benly Super Sport that, "Primarily, essentials of the motorcycle consists in the speed and the thrill," while Cycle Worlds Kevin Cameron says that, "A sportbike is a motorcycle whose enjoyment consists mainly from its ability to perform on all types of paved highway – its cornering ability, its handling, its thrilling acceleration and braking power, even (dare I say it?) its speed."
Motorcycles are versatile and may be put to many uses as the rider sees fit. In the past there were few if any specialized types of motorcycles, but the number of types and sub-types has proliferated, particularly in the period since the 1950s. The introduction of the Honda CB750 in 1969 marked a dramatic increase in the power and speed of practical and affordable sport bikes available to the general public.
This was followed in the 1970s by improvements in suspension and braking commensurate with the power of the large inline fours that had begun to dominate the sport bike world. In the 1980s sport bikes again took a leap ahead, becoming almost indistinguishable from racing motorcycles. Since the 1990s sport bikes have become more diverse, adding new variations like the naked bike and streetfighter to the more familiar road racing style of sport bike.
With the emphasis of a sport bike being on speed, acceleration, braking, and maneuverability, there are certain design elements that most motorcycles of this type will share. Rider ergonomics favor function. This generally means higher foot pegs that move the legs closer to the body and more of a reach to a lower set of hand controls, such as clip on handlebars, which positions the body and weight forward and over the tank. Sport bikes have comparatively high-performance engines resting inside a lightweight frame. High tech and expensive materials are often used on sport bikes to reduce weight.
Braking systems combine higher performance brake pads and disc brakes with multi-piston calipers that clamp onto oversized vented rotors. Suspension systems are advanced in terms of adjustments and materials for increased stability and durability. Front and rear tires are larger and wider than tires found on other types of motorcycles to allow higher cornering speeds and greater lean angles. Fairings may or may not be used on a sport bike; when used, fairings are shaped to reduce aerodynamic drag as much as possible and provide wind protection for the rider.
The combination of rider position, location of the engine and other heavy components, and the motorcycle's geometry help maintain structural integrity and chassis rigidity, and determine how it will behave under acceleration, braking, and cornering. Correct front-to-rear weight distribution is of particular importance to the handling of sport bikes, and the changing position of the rider's body dynamically changes the handling of the motorcycle. Because of the complexity of modeling all the possible movements of different sized riders, to approach perfect tuning of a motorcycle's weight distribution and suspension is often only possible by having a bike customized or at least adjusted to fit a specific rider. Generally, road racing style sport bikes have shorter wheelbases than those intended for more comfortable touring, and the current trend in sport bike design is towards shorter wheelbases, giving quicker turning at the expense of a greater tendency for unintentional wheelies and stoppies under hard acceleration and braking, respectively.