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A motorcyclist's glossaryBy Bill Andrews
Fact is, it's just the names and terms that have evolved over the years to describe the sport of motorcycling. Here's a quick primer. By no means is this list complete. If you've heard or seen a term that you would like to see, send it via e-mail here, and we'll add it to the list. ABS Antilock Brake System. A component added to the braking system that detects wheel lock up. The system then modulates the brakes at that point with the idea of stopping you faster than you could yourself. AHRMA American Historic Racing Motorcycle Association. Sanctioning body for vintage motorcycling competition, it's a member-owned non-profit association dedicated to enhancing the sport of historic motorcycle racing for the enjoyment of riders and spectators. Aftermarket Any items or accessories you buy that are not from the Original Equipment Manufacturer.
Anti-Dive system A front-end suspension component that reduces how much the forks compress under braking, popular in the late 1980s, but seldom used now. Bagger A motorcycle with touring accessories like saddlebags, top box, a trunk, etc.
Brake Horsepower (BHP) Although theoretically equal to standard horsepower, "brake" horsepower specifies that a specific engineering process was used to arrive at that horsepower number. (See also: Horsepower and Torque) Cam A metal shaft with oval "lobes" that rotates to open the valves in a four-stroke engine.
Clip-ons Handlebars that are clamped around the top of the fork tubes, rather than bolted to the top triple-tree. This lowers a rider's upper body on the front of the motorcycle for a racier body position. Counterbalancer A weight in the engine that spins with the rpm to smooth out engine vibrations. Countersteering The input a motorcyclist gives to the handlebars in order to steer: push the right handlebar to go right, or push the left handlebar to go left.
Displacement The size of the engine; specifically, the total volume found in the cylinders. This is usually expressed in cc (cubic centimeters) or ci (cubic inches). Generally, the larger the displacement, the more powerful the motor. DOHC Dual Over Head Cams. Two camshafts found in the head or top of the engine that open and close the valves. Two cams allow more precise control than one.
Engine cut-off switch Usually located on the right handlebar switch housing, this switch allows the motorcyclist to turn off the engine without removing his or her hand from the handlebar. Also known as the "kill switch." Ergonomics The study of body posture, and the positioning of instruments, to create a good human-to-machine interface. "Good ergonomics" refers to how well a motorcycle fits a rider for its intended use.
Flickable and Flickability Used to describe the agility of a motorcycle, or how quickly a rider can flick the bike from side to side in turns. Forks The sprung metal tubes that connect the front wheel to the motorcycle triple-tree. Four-stroke engine This is the most common engine design found in street motorcycles today. It refers to the number of times a piston moves up and down through each power cycle. 1) A downward stroke brings in the fuel/air mixture; 2) an upward stroke compresses the fuel/air mixture; 3) a downward stroke results when that mixture is ignited and expands, and finally; 4) an upward stroke expels the exhaust gases. Fuel-injection (also EFI) A device that serves the same function as a carburetor, but uses computer-controlled jets to inject atomized fuel and air into the air stream going into the engine. Gypsy Tour A current AMA touring term that came from the early days of motorcycling, when riders all over the country suited up for a day-long ride to a favorite destination. The implication is that you are traveling without time or distance constraints. High side A type of crash resulting when the rear wheel starts to slide in a turn, then suddenly grips, flipping the bike sideways. (See also: low side) Holeshot In 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." 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. (See also: Torque) Kill switch See engine cut-off switch. Line (in relation to a turn) The predicted or preferred path a motorcycle will make through a turn. Low side A crash that results from a wheel losing traction, allowing the bike to fall sideways. (See also: high side)
Naked Bikes Sport or standard motorcycles with minimum bodywork, fairings or windshields.
One-off A product or part that is not designed to be mass produced. It can refer to a one-of-a-kind bolt-on or a fully customized motorcycle. Pillion or P-Pad A small cushion designed for carrying a passenger mounted behind a solo saddle. Rake The angle the forks are from perpendicular, usually expressed in degrees. Rat Bike A motorcycle that's been kept running by any means possible, usually with mismatched parts and minimal maintenance. (See: Get your Sportster running Parts I and II)
RPM Revolutions per minute. A term used to describe how fast a motor is spinning. Also known as "revs." Roost The debris kicked up by a spinning rear wheel. Used as a verb, to leave someone behind.
SOHC Single Over Head Cam. A single cam shaft found in the head or top of the engine that activates the valves.
Stretch Used by customizers, an expression of how much a tank or frame has been elongated from its stock design. Squid A term generally associated with a new or reckless motorcyclist seen riding erratically and/or beyond his or her capabilities.
Tachometer A gauge that measures how fast an engine is spinning. The measurement is usually expressed in revolutions per minute. Also: "tach." Tank-slapper What happens in rare cases when a motorcycles handlebars slap back and forth at high speed, often due to alignment or suspension issues. Thumper A single-cylinder, four-stroke motorcycle engine. Torque A unit of measure describing the twisting force, or leverage, an engine can exert on the rear wheel. Typically, an engine with a lot of torque will have the potential to speed up faster at lower rpms. (See also: horsepower)
Triple tree The two metal plates that connect the fork tubes to the steering stem, sometimes also used as a handlebar mount. Two-stroke engine A once-common type of engine now found almost exclusively in off-road motorcycles. A two-stroke motor fires once with every two strokes of the piston. 1) Once fired, the downward stroke of the piston delivers power and then draws in a mixture of fuel, air and oil which displaces the exhaust gases in the combustion chamber; 2) the upward stroke compresses the mixture for ignition. Vintagenous adj, adv. (from vintage). 1) Of or relating to a
certain euphoria or wistfulness of the old times, which is sometimes
strong enough to overcome one, possibly to the extent of causing the
welling up of tears; 2) demonstrating a connection with the past. © 2004, American Motorcyclist Association |


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To some, motorcyclists sound like they are speaking a second
language.
Apex
The middle or center point of a turn.















