A fuel tank that fits over the top tube of the motorcycle frame.
Small, two-wheeled, utilitarian motorbike with a step-thru frame.
An electronic sensor unit on a motorcycle conveying information about an engine to a warning light or other component.
An electronic control system in which a hydraulic, pneumatic, or other type of larger-powered controlling mechanism is assisted and controlled by a low-energy signal.
A final drive system on some motorcycles that utilizes a shaft to transmit power to the rear wheel, as opposed to a chain or belt drive. This system requires the least user maintenance.
Unwanted motion in the rear end of motorcycles with a shaft drive. While under acceleration, the rear suspension stiffens and the machine lifts itself. When decelerating the rear suspension is compressed, giving the opposite effect. It is considered a drawback for some traditional shaft-drive designs. Some of the modern, shaft-drive systems utilize newer technology to reduce this effect.
A one-wheeled carriage for a single passenger attached to the side of a motorcycle, producing a three-wheeled vehicle.
A lightweight motorized bike manufactured from 1935 to 1960 in Louisiana. Starting the engine was accomplished by straddling the bike and taking a few brisk steps. The motion of the rear wheel turned the motor over, and you were on your way.
Asbestos-free brake pads made of sintered metal, with excellent friction coefficient and heat resistance characteristics. Sintering is a method for making objects from powdery metals by heating without melting until the particles adhere to each other.
One of many small incisions on a tire’s surface for the purpose of improving traction.
Racetrack-only tires, so named because they have no tread at all, just a smooth surface so that the maximum amount of rubber grips the asphalt.
Specialized clutches developed for racing motorcycles to mitigate the effects of engine braking when riders would decelerate as they entered corners. They are designed to partially disengage or “slip” when the rear wheel tries to drive the engine faster than it would normally. The engine braking forces in conventional clutches will normally be transmitted back along the drive chain causing the rear wheel to hop, chatter or lose traction. This is especially noted on larger displacement four-stroke engines, which have greater engine braking than their two-stroke or smaller displacement counterparts. Slipper clutches eliminate this extra loading on the rear suspension giving riders a more predictable ride and minimize the risk of over-revving the engine during downshifts. Slipper clutches can also prevent a catastrophic rear wheel lockup in case of engine seizure or transmission failure. Generally, the amount of force needed to disengage the clutch is adjustable to suit the application.
To feather or fan the clutch lever back and forth to prevent stalling the engine or spinning the rear tire.
The serpentine tar strips sometimes used to fill cracks on a racetrack.
The non-profit Snell Memorial Foundation was formed in 1957 and is the world’s most popular independent motorcycle helmet testing organization. A Snell rating on a helmet, indicated by a sticker inside the helmet, states that the helmet has passed performance tests.
A motorcycle that appears to have a hard-tail rear suspension but in reality has shock absorbers that are hidden from view.
A single cam shaft found in the head or top of the engine that activates the valves. (Compare DOHC).
Motorcycle speedway is a specialized sport run on oval, dirt tracks with usually four and sometimes up to six riders from two teams in each race competing over four laps. Speedway motorcycles have no brakes so competitors powerslide (or broadside) their machines sideways into the turns as a way to reduce speed in the corners. A variant of Track racing, Speedway is administered internationally by the FIM.
A motorcycle frame with a single main structural member from which the engine is suspended. Also known as a backbone frame.
A focused motorcycle designed for speed and handling. These machines are usually equipped with aerodynamic bodywork.
A motorcycle that combines some of the handling and power of a sport bike, with some of the amenities of a touring bike, like saddlebags, comfortable ergonomics, etc. Not as focused as either a pure sport bike or a pure tourer.
