Sports Cycle

Motorcycle A to Z : Cycle Babble Glossary

Are you often confused by some of the things your bikers friends say ? Like any hobby or geek-o-meter, there are common motorcycle terms that we all come to learn, and then there is some of the more bizarre slang you can spend a lifetime behind the engine never understanding. Below we’ve compiled a collection of common Motorcycle and Bikers slang to help lift the veil on their mystery.

A

ABS (Antilock Brake System) : The ABS detects when a wheel is not turning and releases pressure to the brake on that wheel, preventing a skid.

Aftermarket : The sector of the market that sells parts and accessories other than OEM (Original Equipment Manufacturers).

Airheads : A term for older, air-cooled BMW Boxer Twins.

Ape hangers : A term coined at the height of the custom-bike movement to describe tall handlebars that forced the rider to reach skyward to grasp the controls, making the rider adopt an ape-like posture.

B

Bagger : A motorcycle equipped with saddlebags and other touring amenities.

Belt-drive system : A final-drive system that transmits the power to the rear wheel via a drive belt.

Big Twins : The engines in the larger Harley-Davidson bikes.

Bobbers : The custom bikes American riders built after World War II where the owners cut off, or “bobbed,” much of the bodywork.

Bottom end : The bottom part of the engine, where the crankshaft and (usually) the transmission reside.

Boxer : A two-cylinder engine with the pistons opposing each other, resembling fists flying away from each other.

Brakes (disc and drum) : Disc brakes are located on the front tire and use stationary calipers that squeeze pads against the discs that rotate with the wheel. Drum brakes, on the other hand, are located on the rear wheel and use horseshoe-shaped brake shoes that expand against the inner surface of the wheel hub.

C

Café chop : Converting a stock motorcycle into a café racer is known as doing a café chop on a bike.

Café racer : Motorcycles modified to resemble racing motorcycles from the 1950s and 60s. They are called “café racers” because their owners supposedly raced from café to café in London, where the bikes first appeared in the 1960s.

Cam (camshaft) : A rod with lobes on it that opens the valves.

Carbon fiber : A high-tech material favored in many motorcycle applications because it is extremely strong, light, and inexpensive. The distinctive look of carbon fiber has become trendy.

Carburetor : A device that mixes fuel with air to create the fuel charge burned in the combustion chamber.

Cases : The two clam-shell-like halves in the bottom end of the engine surrounded by a metal shell.

Centerstand : A stand that supports the motorcycle in an upright position.

Centerstand Tang : A small lever attached to the centerstand.

Chain drive system : A final-drive system that transmits the power to the rear wheel via a chain.

Chassis : The combined frame and suspension on a motorcycle.

Chopper : Once used to describe a custom motorcycle that had all superfluous parts “chopped” off in order to make the bike faster, a chopper today is a type of custom bike that usually has an extended fork, no rear suspension, and high handlebars.

Clip-ons : Handlebars that attach directly to the fork tubes, rather than to the top yoke, that hold the fork tubes together.

Clutch : A device that disengages power from the crankshaft to the transmission, allowing a rider to change gears.

Combustion chamber : The area at the top of the cylinder where the fuel charge burns and pushes the pistons down.

Coming on the cam : The term used when a four stroke reaches its powerband.

Coming on the pipe : The term used when a two stroke reaches its power band.

Connecting rods : These attach the crankshaft to the pistons via the eccentric journals, and the rods’ up-and-down movement is converted into a circular motion through the design of the journals.

Constant-radius turn : A turn with a steady, nonchanging arc. In a decreasing-radius corner, the arc gets sharper as you progress through the curve, while in an increasing radius corner, the arc becomes less sharp.

Contact patch : The area of your tire that actually contacts the road while you ride.

Counterbalancer : A weight inside an engine that cancels out some of the engine’s vibration.

Countersteering : The way you use the handlebar to lean the bike into a turn. If you want to turn right, you push the handlebars to the left, and vice versa.

Cowlings : A piece of bodywork that covers the engine area.

Crotch rocket : A term some people use to refer to sportbikes.

Crowns : The tops of the pistons.

Cycle : The up-and down motion of the piston. The terms cycle and stroke are used interchangeably when referring to engine types.

Cylinder block : The hunk of aluminum with holes bored through it, inside which the pistons move up and down.

Cylinders : The hollow shafts in the top end of an engine inside which internal combustion occurs.

D

Decreasing-radius corner : A turn where the arc gets sharper as you progress through the curve.

Dirtbike : Bikes intended for off-road use that aren’t legal to ride on public roads. Sometimes the term pure-dirt is used to distinguish a dirtbike from a dual-sport motorcycle.

Discs : These are the metal rotors the caliper presses the pads against to brake.

Double-cradle frame : A bike frame with two steel tubes circling the engine from the front and “cradling” it.

Dresser : A motorcycle set up for long-distance touring.

Dual sport : Street-legal motorcycles with varying degrees of off-road capabilities. Also called dual-purpose motorcycles.

Eccentric journals : These are used to attach the connecting rods to the crankshaft (also called metal shafts).

Ergonomics : The science used to design devices, systems, and physical conditions that conform to the human body. A prime consideration when designing a motorcycle.

Evolution (Evo) : When Harley-Davidson began using aluminum to build its cylinder jugs, it called this new engine the Evolution.

F

Fairings : The devices mounted at the front of a motorcycle to protect the rider from the elements. These range from simple, Plexiglas shields to complex, encompassing body panels.

False neutral : When you fail to engage gears and the transmission behaves as though it is in neutral, even though it isn’t.

Flat cylinders : Found in the flat-four- and flat-six-cylinder engines used in Honda’s Gold Wings, the cylinders are arranged in a flat, opposing configuration.

Foot paddling : The way an unskilled rider “walks” his or her motorcycle around at low speeds.

Forks : The metal tubes holding the front wheel to the rest of the motorcycle.

Four-cylinder bike : A motorcycle with four cylinders.

Fuel-injection system : This mixes the fuel-air charges and forcibly injects them into the combustion chambers, unlike carburetors, which rely on the vacuum created by the engine to draw the charges into the combustion chambers.

G

Garbage wagon : A scornful term used by some outlaw bikers to describe touring bikes.

Gearhead : A person with a strong interest in all things mechanical; a motorcyclist.

Gearset : A set of gears within a bike’s transmission.

H

High siding : Pitching a bike over away from the direction you are turning. The most dangerous kind of crash.

Horsepower : A measure of an engine’s strength.

Hydroplane : When your tires start to float on top of water, causing them to lose contact with the road’s surface.

I

Increasing-radius corner : A turn where the arc becomes less sharp as you go through the curve.

Inline six : An engine with six cylinders in a row.

Inline triple : An engine with three cylinders placed in a row.

Iron Butt Rally : The most grueling long-distance motorcycle rally in the world. To finish, the rally requires that you ride at least 10,000 miles in 11 days.

K

Knucklehead : A term for Harley-Davidson’s first overhead-valve Big Twin, introduced
in 1936.

L

L-twin engine : A V-twin engine with its cylinders splayed apart at a 90-degree angle, which creates a smoother-running engine. These engines can either be placed transversely (crosswise), or longitudinally (lengthwise) in the motorcycle frame.

Lane splitting : Riding between lanes of traffic on a freeway.

Laying the bike down : A crash where you slide down on one side of the bike.

Leviathan : Used to describe big, multicylinder dual sports.

Lugging the engine : Letting the RPMs fall below the engine’s powerband.

M

Manual transmission : A device consisting of a set of gears (the gearset), that alter the final-drive ratio of a vehicle to enable an operator to get up to speed. Automatic transmissions do not have gearsets but rather use a complex system of fluid and metal bands to vary the final-drive ratio of a vehicle.

N

Naked bikes : Bikes without any type of fairing.

O

Oilheads : Newer, air-and-oil-cooled BMW Boxer engines.

Open-class : When referring to street-legal sportbikes, open-class designates motorcycles with engines that displace more than 800 cubic centimeters of volume.

Original Equipment Manufacturers (OEM) : The companies that build the bikes.

Orphan bikes : Rare bikes that are no longer in production.

Otto cycle : The four-stroke engine is sometimes called the Otto cycle, in honor of its inventor, Otto Benz.

Overbore :When you overbore your engine, you drill out the cylinders and then put oversized pistons in the holes, effectively increasing your engine capacity.

Overhead cam system : A system where the cam rides directly on top of the valve
stems.

P

Panhead : A term for Harley-Davidson’s second-generation overhead-valve Big Twin, introduced in 1948.

Parallel-twin engine : A two-cylinder engine with its cylinders placed side-by-side in an upright position.

Pistons : The slugs moving up and down within the cylinders.

Powerband : A certain RPM (revolutions per minute—how many times per minute an engine’s crankshaft spins around) range in which an engine makes most of its power.

Primary drive : A drive chain connecting the engine’s crankshaft to its transmission.

Production motorcycles : The bikes manufacturers produce to sell to the general public, rather than bikes built specifically for racers.

Pushrod system : In a pushrod system, the cams are located below the cylinder heads and push on the rocker arms by moving long rods, called the pushrods.

R

Radial : When used to describe a tire, refers to the way the cords of a tire are constructed. While radial tires have long been used with automobiles, they are just now being used on motorcycles.

Rain grooves : Channels cut into a road’s surface to help water run off the road during a rainstorm.

Repair link : A link in some motorcycle chains that can be disassembled for chain repair.

Repli-racers : Hard-edged sportbikes. These motorcycles are characterized by riding positions that tuck the rider into an extreme crouch, forcing him or her to practically lay down on the fuel tank.

Revolutions per minute (RPM) : The number of times the crankshaft spins around each minute. Often, the term revs is used, especially in conversation.

Riding two up : Carrying a passenger on your bike.

Rocker arms : Devices that work like upside-down teeter totters and push on the valve stems.

Rubber-mounted : Rubber-mounted engines use a system of rubber cushions and/or jointed engine mounts to isolate engine vibration from the rider.

S

Shaft drive system : A final-drive system that transmits the power to the rear wheel
via a drive shaft.

Shaft jacking : Shaky or bumpy motion created by the impact of acceleration and then fed back into the bike’s frame.

Shovelhead : A term for Harley’s third-generation overhead-valve Big Twin engine,
introduced in 1966.

Sidecars : Small carriages attached to the side of a motorcycle to provide extra carrying
capacity.

Sissy bar : The backrest put behind the passenger’s portion of the saddle.

Snicking : The act of shifting a well-functioning transmission is often called snicking, because that’s the sound the action makes. A transmission that doesn’t snick into gear is described as sloppy-shifting.

Solid-mounted : A bike with a solid-mounted engine has the engine bolted directly to the frame tubes.

Splitting the cases : The metal shell surrounding the bottom end is composed of two clam-shell-like halves, called cases. Taking these apart to repair the motor is called splitting the cases. See also bottom end.

Sport tourer : A motorcycle that combines the comfort and carrying capacity of a touring bike with the handling and power of a sportbike with larger fairings and hard, lockable luggage.

Sportbike : A motorcycle designed for optimal speed and handling characteristics, often with extensive bodywork.

Springer fork : Springer-type forks use large, exposed springs to dampen the impact of road irregularities.

Squid : Someone who rides a sportbike on the street as if he or she were on a racetrack.

Steering geometry : The geometrical relationship between the motorcycle frame, the angle of the fork, and the position of the front tire.

Streetfighter : A bare-bones sportbike, stripped of all extraneous body work (also called a “hooligan” bike).

Stroke : The up-and-down motion of the piston.

Suspension : The forks, shocks, and to a degree, tires, of a motorcycle. The springs and fluids in these items that “suspend” the motorcycle frame off of the ground.

T

Tappets : Small metal slugs between the cam and the pushrod or rocker arm.

Telelever system : The most successful alternate front suspension, made by BMW, which takes the shock-absorption function of a hydraulic fork and transfers it to a shock absorber located behind the steering head.

Thumper : Bikes with large-displacement, single-cylinder, four-stroke engines.

Top end : The upper part of the engine, which contains the pistons, cylinders, and valve gear, and the induction system consists of the apparati that mix an air-and-fuel charge and inject it into the combustion chamber, located in the top end.

Torque : A twisting force, and in a motorcycle, it is a measure of the leverage the engine exerts on the rear wheel.

Touring bike : A bike equipped for longer rides with fairings and lockable saddle bags.

Traction : A tire’s ability to grip the road.

Travel : The distance that suspension components, the forks and shocks, move up and down when the bike rides over bumps.

Twin spar-type frame : A bike frame with two steel or aluminum “spars” (flat beams) sandwiched around the sides of the engine.

Two up : A term for carrying a passenger on your motorcycle.

Two-stroke engine : An engine (also called a “stroker”) whose power cycle consists of just two movements, or strokes: The piston moves down, drawing in the fuel-air charge, and then up, combusting the charge.

U

Unitized transmission : A transmission (often referred to as a “unit transmission”) that is an integral part of the engine’s bottom end.

Universal Japanese Motorcycle (UJM) : During the 1970s, the Japanese became so identified with the four-cylinder, standard-style motorcycle that this term was coined to describe them.

V

V-four : An engine with four cylinders arranged in a V-shaped configuration.

V-twin : A two-cylinder engine with its cylinders placed in a V shape.

Valves : Devices consisting of metal stems with flat disks on one end that open and
close to let fuel charges in and exhaust gases out.

Valve guides : Metal tubes that house the valves.

Valve train : The system of valves that let the fuel charges in and let the exhaust
gases out.