Learn Your ABC's! Motorcycle Acronyms To Know

When You're buying motorcycle gear or parts, you run into a lot of acronyms, and they can get pretty confusing. Some people dont even know what OEM stands for and thats our entire website! To inform your buying choices, we put together this guide to what they all stand for.

ABS - Anti-lock Braking System. An electronic safety system that prevents wheels from locking up under braking, by using wheel speed sensors to detect when a wheel is about to stop spinning and reducing brake pressure accordingly. The Insurance Institute of Highway Safety states that motorcycles equipped with ABS crash 31% less than the same motorcycles not equipped with this feature.

Ah - Ampere-hour. A unit of electric charge frequently found in automotive batteries (defined as the amount of energy charge in a battery that will allow one amp of current to flow for one hour.) In other words, a unit used to measure how long a battery will last.

AMA - American Motorcycle Association. The nation's largest and most well-known member-based motorcycle organization, the AMA advocates for riders by representing their interests in government legislation, and also sanctions a wide range of motorcycle-related events and races.

ATGATT - "All The Gear, All The Time." An acronym used by motorcyclists to describe riders who gear up fully - full-face helmet, armored jacket, armored gloves, boots, and possibly armored pants - every time they ride. You never know when or where a crash will happen, so ATGATT is good advice that we recommend to all riders!

ATV - All-Terrain Vehicle. Also known as quads or four-wheelers, these off-road specific recreational vehicles range from outdoors workhorses like the Honda Foreman series to race-ready machines like the Yamaha Raptor. Despite the "quad" and "four-wheeler" moniker, some ATVs have six wheels, and three-wheeled version were popular until they were banned in the late 1980s. Shop our huge ATV parts and accessories section here.

CARB - California Air Resources Board. The agency responsible for clean air in California (and why we can't buy all the cool exhaust systems here that the rest of you guys can.) Note: California is the only state that is even allowed to have its own clean-air agency, having been grandfathered in when the federal Clean Air Act was passed; the remaining states must abide by federal standards set by the EPA.

CCA - Cold Cranking Amperes. This is the unit most widely used to measure the cranking power of vehicle batteries (defined as the amount of current a lead-acid battery can provide at 0 degrees Fahrenheit for 30 seconds, maintaining at least 1.2 volts per cell.) Buyers of powersport batteries, especially for performance applications, tend to favor the smallest/lightest batteries that provide adequate CCAs to crank a given engine.

CE - Conformitee Europeene. A marking that signifies conformity to European Union standards. Motorcycle armor is considered "CE Rated" when it conforms to EU standards of impact protection. You see references to CE ratings often in reference to sport motorcycle gear and protective armor. (Note: CE rating is a self-certification scheme; conformity is declared by gear manufacturers themselves, and not by a testing agency.)

dB - Decibel. The standard for measuring volume of sound. You often hear this in reference to motorcycle exhausts, particularly aftermarket versions. Cities and states often have laws limiting how loud motorcycle exhausts can be in decibels, and these laws vary widely.

DOT/USDOT - (U.S.) Department of Transportation. Tasked with enforcing various aspects of transportation, this is the agency in charge of testing and categorizing vehicles, components, or gear as being legal for use on public roads. States have their own DOTs as well, which is why what is "street-legal" can vary so much from place to place.

ECU/ECM - Engine Control Unit/Electronic Control Module. The "brain" of a motorcycle; the computer that controls various aspects of your bike such as ignition, timing, and fuel control. Adjustments to fueling when modifying intakes or exhausts are done to the ECM with a custom program (AKA a "map").

EFI - Electronic Fuel Injection. A fuel delivery system that has almost completely replaced the carburetor, using small nozzles controlled by a computer (the ECU or ECM) to atomize fuel and inject it directly into the combustion chambers. EFI systems must be tuned with a computer or electronic module, as opposed to manual tuning of jets with a carburetor.

EPA - Environmental Protection Agency. The powerful federal agency tasked with all things environmental, their involvement with the motorcycle world is limited mostly to noise limits, emissions standards, and certification of exhaust equipment. They set a federal limit of 83 decibels for most motorcycles manufactured after 1983 (though local and state agencies, many which have no set noise limits of their own, rarely enforce it.)

EVA - Ethylene-Vinyl Acetate. Also known as "foam rubber", EVA is a strong, waterproof polymer known for its softness and flexibility. It is often used for shock absorption in motorcycle gear, such as in the footbeds of motorcycle boots. Interestingly, melting adhesives (i.e. hot glue sticks) are also made of EVA.

EXUP - Exhaust Ultimate Power valve. A system found in the exhaust system of motorcycles that expands or contracts the diameter of the exhaust with a butterfly valve to match engine speed. Adjusting the exhaust diameter optimizes backpressure for given engine speeds, enhancing low to mid-range performance, and ensuring a more linear power output. The EXUP moniker was given by Yamaha, the first to develop the system, though Honda, Suzuki, and Triumph all now use variations of the same system.

GPS - Global Positioning System. An electronic system that uses signals from a network of satellites to triangulate its own position in real time, with very high accuracy. Only a few years ago this was something motorcyclists could only dream about, but today there are a number of motorcycle specific units that make finding directions on a motorcycle effortless.

HD - Hi-Definition. Most commonly found in reference to video camera equipment and televisions, HD is simply video of higher resolution than standard-definition. Although there is no set standard for what "HD" actually is, generally 720p is the minimum. Action cameras such as the GoPro Hero line record in HD.

HUD - Heads-Up Display. A means of displaying information by projecting it onto a clear screen that a rider can see through without taking his eyes off the road. It's still an emerging technology, but the motorcycle market has some exciting HUD products coming soon.

LCD - Liquid Crystal Display. A flat panel electronic display. In the motorcycle worlds, most commonly used in the gauge clusters of motorcycles and in small electronics. LCDs use very little power, and are commonly found in battery-powered applications.

LED - Light-Emitting Diode. A type of tiny electronic light, made popular in recent years through its use in headlights from auto manufacturers like Audi. LEDs have been used since the 1960s, but advances in technology have made them much more powerful and robust today. LEDs light up instantly, use very little power, and have extremely long lives. They are now used by a number of auto and motorcycle manufacturers as daytime running lights and tail lights, and are finding use in many other applications, such as compact flashlights.

LiFe-PO - Lithium-Ion Phosphate. A modern type of battery used in high-power applications, such as in electric vehicles and power tools, and also as a performance replacement for traditional lead-acid batteries. LiFe-PO batteries are long-lasting, stable, powerful, and very lightweight, though they are more expensive than comparable lead-acid batteries.

MSF - Motorcycle Safety Foundation. A national organization that provides information on and facilitates rider training and licensing. Best known for providing the Basic RiderCourse (often referred to as "BRC"), an introductory course to motorcycling that, in many states, can be done in lieu of a normal DMV exam.

OBD/OBDII - On-Board Diagnostics. An electronic system that allows a motor vehicle to self-diagnose. When a vehicle "throws codes" (DTCs, or Diagnostic Trouble Codes) it is a result of the OBD system diagnosing itself as encountering some problem. This is mostly an automotive standard, but some motorcycles also use the OBD system, allowing them to be diagnosed with an automotive scan tool.

OEM - Original Equipment Manufacturer. The manufacturers of production motorcycles and factory replacement parts. Parts produced by the manufacturers themselves are known as OEM, factory, or stock parts, compared to companies that produce parts only, which constitute the aftermarket.

OHM/OHV - Off-Highway Motorcycle/Off-Highway Vehicle. Any motorcycle or vehicle that is designated as being for off-road use only; not street-legal. Dirt bikes, ATVs, and most UTVs fall into this category. Also refers to open areas designated for use of these vehicles (OHV areas.) Parts and accessories for these vehicles are typically not street-legal and can vary widely, so check your local regulations when shopping for them.

PSI - Pounds per Square Inch. A measurement of pressure; in the motorcycle world, it's most commonly used in reference to tire pressure. Tires have a recommended PSI range printed on the side, and you can adjust the tire pressure within that range to optimize for grip, handling, mileage, or riding with passengers. (In other parts of the world where the metric system is used, the bar - equal to one unit of atmospheric pressure on earth at sea level - is used instead.)

TCS - Traction Control System. An electronic safety system that uses sensors to monitor wheel speed, acceleration, and/or lean angle to predict wheelspin, and interferes by reducing power to prevent a loss of traction. These systems are increasingly found on higher-end sport and touring bikes, and can also be added to existing bikes with aftermarket modules.

TPMS - Tire Pressure Monitoring System. An electronic system that uses sensors mounted inside wheels to constantly monitor tire pressure. TPMS systems can be added to most motorcycles as an aftermarket accessory (though some high-end BMWs and Triumphs can have them fitted from the factory.)

TPR - Thermoplastic Rubber. A flexible polymer blend often found in motorcycle gear, used for its combination of the flexibility and durability of rubber, with the ease of processing of plastic. Found anywhere from knuckle protection and sliders to zipper pull tabs.

TPU - Thermoplastic Urethane. A strong, abrasion-resistant, flexible, and oil-resistant type of polyurethane plastic used in many types of motorcycle gear, such as shoulder and knee sliders in motorcycle jackets and pants, and hardened knuckles in armored gloves

USB - Universal Serial Bus. An industry standard of cables and connectors used in electronics. Most electronic motorcycle devices (cameras, navigation systems, etc.) use USB cables to charge and to transfer information, and USB charging ports can even be added to motorcycles as an accessory.

UTV - Utility Task Vehicle. Also commonly known as side-by-sides, UTVs are small two or four-person off-road utility vehicles. UTVs are similar to ATVs, but are distinguished by their typically larger size, steering wheels instead of handlebars, and most notably, some type of rollover protection integrated into the frame.