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Glossary: Table of ContentsHomenhtsa

Antilock braking system (ABS): A braking system that prevents wheels from locking during braking.

Armor: Padding, hard-shelled material or other impact-absorbing material fitted to a motorcyclist’s apparel. Performance standards exist in Europe for such materials.

Asphalt sealer: Material used to fill and repair cracks in asphalt paving. Materials currently used often create a slick surface that can cause a motorcycle to lose traction.

Automatic-on headlamp: A motorcycle headlamp that is automatically illuminated when the engine is started—also known as daytime running lamp. Required by regulation in many states since 1973 and consequently installed on virtually all street bikes sold in the U.S.

Brake: To stop or slow a motorcycle using the brakes. See also Panic-brake.

Café-racer: Customized motorcycle built in the style currently categorized as a sportbike; popular in the 1970s and early 1980s.

Corner (or cornering): To negotiate a turn in the road. A motorcycle must lean to do so.

Daytime running lamps (DRL): Frontal lighting used to enhance daytime conspicuity of motor vehicles including motorcycles.

DOT: U.S. Department of Transportation

Fairing: Frontal bodywork on a motorcycle intended to make the vehicle more aerodynamic and/or reduce wind pressure on the rider.

FMVSS 218: U.S. Department of Transportation Federal Motor Vehicle Safety Standard No. 218 Motorcycle Helmets.

FMVSS 218 compliant helmet: A motorcycle helmet that complies with U.S. Department of Transportation Federal Motor Vehicle Safety Standard No. 218 (FMVSS 218) for motorcycle helmets.

Front suspension: Often called the “fork” or “forks” because most motorcycles use designs with two parallel legs.

Hurt Report: A study of 900 motorcycle crashes titled Motorcycle Accident Cause Factors and Identification of Countermeasures, authored by H.H. Hurt et al., in 1981. Conducted in the late 1970s, it is considered the most comprehensive study of motorcycle crash causation to date.

Lane splitting: Passing between lanes of stopped or slower-moving vehicles on a motorcycle. Not permitted in most of the U.S., it is allowed in many other countries and may provide a safety benefit. Also called “lane sharing.”

Linked braking: Motorcycle braking systems that use a single control to operate both front and rear brakes.

Manual on Uniform Traffic Control Devices (MUTCD): Contains all national design, application, and placement standards for traffic control devices, including signs, signals, and pavement markings. The MUTCD is published by the Federal Highway Administration (FHWA) under 23 Code of Federal Regulations (CFR), Part 655, Subpart F.

Motorcycle safety: Reducing motorcycling crashes, injuries and fatalities through risk management and countermeasures.

Overbrake: Applying too much force to a brake during a stop, which causes a wheel to stop turning. This can result in loss of directional control (particularly if the rear wheel stops rolling) or upset the motorcycle and cause a crash (a common result of overbraking the front wheel).

Panic-brake: An emergency stop, requiring hard, effective controlled brake application, so called because it is often conducted during a moment of panic.

Position lamps: Additional filaments in a motorcycle’s front turn-signal assemblies that act as full-time running lights to increase conspicuity, distance perception by other drivers, and awareness.

Risk management: The practice of planning for and reducing risk.

Semi-chopper: A motorcycle customized in the style currently categorized as cruiser. In the 1970s, such machines frequently included lengthened front suspension.

Swerve (or swerving): To rapidly change direction, normally employed to avoid an obstacle.

Tiered licensing: A licensing system that provides for operating restrictions based upon motorcycle engine displacement.

Tubeless tire: A tire that retains air without an inner tube. An inner tube (used on a tube-type tire) is necessary to retain air pressure when the wheel design or the tire cannot do so. However, an inner tube typically deflates rapidly when punctured, and this sudden deflation can cause a quick reduction of control on a motorcycle. A tubeless tire typically deflates much more slowly, providing a motorcyclist with warning before control is reduced significantly. Whether a tube-type or tubeless tire is chosen normally depends on the kind of wheel to which it is fitted.

Tube-type tire: See Tubeless tire.

Underbrake: Failure to apply the brakes to their full capability, resulting in a longer than needed stopping distance. This is usually caused by fear of the results of overbraking.

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