Technology / Motorcycle Glossary
Head Tube: The outer tube which holds the bearings that allow the front fork steer tube to pivot freely.
Headlight Modulator: A Headlight Modulator is a device that turns your motorcycle headlight into an attention-getter. It makes your headlight beam pulsate 240 times per minute during daylight hours.
Heel-Toe Shifter: Normally, shifting on a motorcycle is done by placing your foot under the shift lever, squeezing the clutch lever all the way to the grip and then kicking upward smartly for each gear change . . . View Full Definition
Helical Gear: The leading edges of the teeth are not parallel to the axis of rotation, but are set at an angle. Since the gear is curved, this angling causes the tooth shape to be a segment of a helix. Th . . . View Full Definition
Hells Angels: Movie produced in 1930 by Howard Hughes. Also a B-17 squadron in WWII. The name was subsequently taken by a group of motorcyclists for their motorcycle club. This club has expanded and has m . . . View Full Definition
Helmet Hair: Wearing a motorcycle helmet tends to mess up one's hair. Removing the helmet usually leaves hair sticking out in all directions. This is called helmet hair. It can be minimized by use of spe . . . View Full Definition
High Side: A type of motorcycle crash that occurs when the rear wheel starts to slide in a turn (sometimes due to a locked brake and the resulting skidding tire), and then suddenly grips the pavement ( . . . View Full Definition
Highsiding: Highsiding occurs when the rider of a motorcycle is flipped over the handlebars of the bike. This most often occurs when the rider locks the rear brakes during a panic stop and then releases . . . View Full Definition
Highway Pegs: Footrests situated forward of the rider so the legs can be stretched out to relieve highway fatigue.
HOG: Has various meanings from Harley Owners Group to simply a Harley rider or the machine itself.
Holeshot: In motorcycle racing, the drive from a standing start up to racing speed. Generally, the rider who makes the strongest start is said to have gotten the “holeshot.”
Hollister Incident: A band of bikers rode into Hollister, CA. on July 4, 1947 for a 3-day rally. Some drunkenness occurred and the press made a sensational story out of it that appeared in Life magazine. Most o . . . View Full Definition
Homologation: Homologate means “to approve, especially to confirm officially.” Homologation is the approval process of the governing body over a competitive race. The process certifies that each of the co . . . View Full Definition
Honda Dream: First Honda model that popularized motorcycles to Americans in the early '60s.
Horizontally Opposed: Type of engine layout in which the cylinders are placed at 180° to one another. It is also described as a flat twin or flat four, etc. Also known as a boxer engine.
Horsepower: A unit of measurement used to describe an engine’s strength. Typically, the more horsepower an engine produces, the faster the motorcycle can potentially go. The term “horsepower” was invent . . . View Full Definition
Hub-Center Steering: One of several different types of front-end suspension/steering mechanisms used in motorcycles. Hub-center steering is characterized by a swingarm that extends from the bottom of the engine/ . . . View Full Definition
Hunting (engine): The uneven running of an engine, due to air/fuel mixture being too rich.
Hurt Report: Harry Hurt conducted the definitive study on motorcycle accidents at USC in 1979. His team studied 3622 accidents and drew many important conclusions relative to motorcycle safety. This repo . . . View Full Definition
Ignition Timing: The process of setting the time that a spark will occur in the engine combustion chamber (during the power stroke) relative to piston position or crankshaft rotation. Setting the correct ign . . . View Full Definition
Inlet Over Exhaust (IOE): Valve layout used on some early machines in which the exhaust valve was mounted to the side of the engine and the mechanically operated inlet valve was positioned above the exhaust.
Inline: Engine layout in which the cylinders are arranged in a row. For example, an “inline 4? engine would have 4 cycliners aligned in one row.
Inline 4: An Inline 4 is an engine having four cylinders in a row.
Integrated Brakes: Integrated Brakes are used on motorcycles to link together the front and rear brakes. Many inexperienced riders in panic situations tend to overuse the rear (foot) brake. This causes skiddin . . . View Full Definition
International Six Day Enduro (ISDE): The oldest “off road” motorcycle event on the FIM Calendar. (Originally titled the “International Six Day Trial,” or ISDE, since 1980 it has been called the “ISD Enduro.”) First held in 1913 . . . View Full Definition