Checkered Flag – First across wins: race over
Black Flag – Rider disqualified or problem with motorcycle
Green Flag – Race start signal, race in progress when all is “go”
Red Flag – Race stopped, sometimes to be restarted
White Flag – One lap left to race
Yellow Flag – Caution, do not pass if flag is waving
Yellow and Red Striped Flag – Caution, indicates debris, fluid or hazard
A transfer of technology from road racing machines to street bikes of today. The brake calipers attach to the front fork with bolts aligned with the caliper centerline (as opposed to bolts through the side). This change increases braking performance and reduces weight.
The angle the forks are from perpendicular, usually expressed in degrees. (Compare trail).
Inlets in the front of the fairing, connected to ducts leading to the airbox, force fresh, cool air into the intake system, creating a supercharging effect.
A motorcycle that’s been kept running by any means possible, usually with mismatched parts and minimal maintenance
Racing-style footrests fitted towards the rear of the machine to allow the rider to adopt a racing crouch.
An electrical component in motorcycle charging circuits that converts alternating current into direct current.
The maximum number of revolutions per minute an engine can run before damage occurs. The name is derived from the actual red line manufacturers typically put on the tachometer.
Reed valves are commonly used in high-performance versions of the two-stroke engine, where they control the fuel-air mixture admitted to the crankcase. As the piston rises in the cylinder the resulting vacuum opens the valve and admits the fuel-air mixture. As the piston descends, it raises the crankcase pressure causing the valve to close to retain the mixture and pressurize it for its eventual transfer through to the combustion chamber
Also known as an “RPM Limiter”: A rev limiter reduces the power of an engine when a certain RPM is reached. As an engine safety device, a rev limiter is placed in the electronic circuitry to prevent the engine from over-revving. For example, if you have a motorcycle throttle wide open and miss a shift, the rapid increase in RPM’s could damage engine parts.
High performance sport bike from Japan
A clutch generally consists of a disk which, in its normal state, connects the engine to the transmission. When the motorcycle is driving along, the mechanism is released or “engaged”. During a stop at traffic lights, the right hand lever is pulled in to “disengage” it. “Riding the clutch” means holding the point of friction, right at the point where engine and transmission are only just coupled. Excessive use of this technique can cause early wear of the mechanism.
Rim locks are used to prevent tires from slipping around motorcycle rims. They are primarily used on off-road bikes and/or any application using low tire pressure for enhancing off-road traction. Aggressive off-road tires or under-inflated tires are prone to slipping on the rim under hard acceleration or braking. In such cases, a rim lock saves the inner tube’s valve stem from damage.
A suspension system that becomes harder to compress the further it is compressed. This is usually achieved by a mechanical lineage with variable leverage ratio.
A term used to define injuries to the skin when a rider falls or is thrown from the motorcycle and lands or slides on the pavement. One reason riders wear full-face helmets, gloves, armored jackets, chaps, and boots is to minimize road rash.
Type of motorcycle with no fairing or wind protection, and where the bike’s engine and system components are visible. It came back into fashion at the start of the 90s as a tribute to past motorcycles. It is now a key style with subfamilies (basic, retro, urban, racing, etc.).
A centrally pivoted lever that transmits the motion of the camshaft to open and close the valves.
The assembled frame, wheels and suspension of a motorcycle.
The debris kicked up by a spinning rear wheel. Used as a verb, to leave someone behind.
An internal combustion engine that does not have pistons, camshafts, valvetrain, or a crank shaft. It has three main moving parts, which are two rotors and an eccentric shaft, also referred to as an output shaft. (Compare to Boinger)
A term used to describe how fast a motor is spinning. Also known as “revs.” (Compare Tachometer).
