The acronyms of the two-wheeledThe lexicon of all motorcyclists

BMW Motorrad's Dynamic ESA (Electronic Suspension Adjustment) is a semi-active suspension technology designed to automatically adjust the motorcycle's damping and ride height to riding conditions.

An evolution of the classic ESA, this system uses travel sensors, the inertial measurement unit (IMU), and braking data to continuously analyze the vehicle’s dynamics. In a matter of milliseconds, the control unit electrically adjusts the suspension’s rebound and compression damping via solenoid valves. Dynamic ESA thus reduces nose dive during braking, wheelie during acceleration, and maintains optimal stability when cornering or on uneven road surfaces.

Linked to the riding modes (Road, Dynamic, Enduro), it adapts its responsiveness to the selected riding style. In its “Next Generation” version, the system features automatic load compensation, automatically adjusting spring preload based on the vehicle’s load.

Engine Brake Control (EBC) is an electronic assist system designed to regulate engine braking during heavy deceleration and downshifts.

On high-displacement motorcycles, mechanical drag when the throttle is closed can cause the rear wheel to skid, lock up, or become unstable when entering a turn. EBC resolves this issue by cross-referencing wheel speed data, the selected gear, and the lean angle measured by the inertial measurement unit (IMU). When excessive stress is detected on the rear end, the electronic control unit (ECU) instructs the Ride-by-Wire system to open the throttle valves very slightly to allow a small amount of air to flow in, thereby reducing engine drag.

Adjustable to several sensitivity levels depending on the rider’s profile or weather conditions, the EBC allows you to customize the bike’s braking behavior. It stabilizes the chassis, makes cornering smoother, and complements the action of the anti-dribble clutch.

The system is called MSR at BMW and EBM at Yamaha.

The ECU (Electronic Control Unit) is the “brain” of the motorcycle. This control unit centralizes and processes in real time a wealth of information transmitted by numerous sensors located throughout the motorcycle: engine speed, throttle position, coolant and air temperature, atmospheric pressure, and exhaust gas composition.

Using stored mapping data, the ECU analyzes this information at high frequency to instantly control the engine’s actuators. It thus adjusts the amount of fuel injected, the spark plug ignition timing, the opening of the electric throttle valves (Ride-by-Wire), and the exhaust valve.

EXUP (Exhaust Ultimate Power Valve) is a variable exhaust valve technology developed by Yamaha in the late 1980s to optimize the performance of 4-stroke sports engines.

In high-performance engines, the valve overlap required at high RPMs results in fresh air losses and a lack of torque at low and mid-range RPMs. EXUP resolves this issue by incorporating a servo-controlled rotary valve in the exhaust manifold, which is directly controlled by the ECU based on engine speed and throttle position.
- At low and mid-range RPMs, the valve partially closes to increase backpressure in the manifold, which prevents premature scavenging of the air-fuel mixture and significantly boosts torque and smoothness.
- At high RPM, the valve opens fully to allow the exhaust gases to flow freely and deliver maximum power. First introduced on the FZR 1000 before becoming the signature feature of the YZF-R1 and R6, EXUP revolutionized supersport bikes by eliminating power gaps during acceleration and broadening the engine’s usable range without compromising pure performance.

Kawasaki's Forward Collision Warning (FCW) is a forward collision warning system based on the ARAS technology suite developed in partnership with Bosch.

Using a millimeter-wave radar sensor hidden beneath the headlight (notably on the Ninja H2 SX), the FCW continuously monitors the motorcycle’s speed and the distance to the vehicle ahead. When it detects a critical closing distance that could lead to a collision, the system does not apply the brakes: it immediately displays a very clear visual alert on the TFT screen as well as a flashing red light strip on the instrument panel. The rider thus retains full responsibility and control over emergency braking or evasive maneuvers.

Configurable with three sensitivity levels (Early, Standard, Late) or fully deactivatable via the menus, FCW works in conjunction with Adaptive Cruise Control (ACC) and Blind Spot Detection (BSD). By alerting the driver within the first fractions of a second of inattention, this system provides preventive safety.

GTT (Glide Through Technology) is an electronic low-speed riding assistance system developed by TVS. This system allows the motorcycle to move forward autonomously in the first few gears without any input from the rider on the throttle.

The GTT system relies on the synergy between the electronic control unit (ECU) and the Ride-by-Wire throttle. When the rider gradually releases the clutch lever at very low engine speeds (without accelerating), the ECU detects the drop in engine speed. It then instantly and automatically adjusts fuel injection to keep the engine just above its stalling threshold.

Launched in early 2000 by Yamaha Motor Company, GYTR brings together all the high-performance parts, accessories, and kits developed specifically for racing. Designed, tested, and validated by Yamaha engineers, GYTR components optimize every aspect of the bike: engine, intake, exhaust, suspension, electronics, braking, ergonomics, and aerodynamics.

For several years now, Yamaha has also offered GYTR Pro Shops in Europe, Japan, and the United States. These specialized workshops are certified to assemble, configure, and maintain 100% racing motorcycles like the R1 GYTR Pro.

The system known as HESD (Honda Electronic Steering Damper) is an electronically controlled steering damper developed in collaboration with Showa to eliminate the risk of wobbling without compromising handling.

On a conventional mechanical damper, constant hydraulic braking makes the steering feel heavy at low speeds. The HESD overcomes this problem by incorporating a solenoid valve controlled by the engine control unit (ECU) that adjusts the flow of oil in the hydraulic chamber in real time based on speed and acceleration. At low speeds or during maneuvers, the valve remains open to allow oil to flow freely, maintaining very light steering. At high speeds or during sharp re-accelerations that could cause the front end to lift, the ECU gradually restricts fluid flow to stiffen the steering, absorbing shocks and locking the bike onto its line.

Introduced on the CBR 1000 RR Fireblade in 2004 and later on the CBR 600 RR, this system offers a balance between responsiveness at low speeds and stability at high speeds, without requiring any manual adjustment by the rider.

Hill Hold Control (HHC), or hill start assist, is an electronic assistance system designed to keep the motorcycle stationary on an incline without the rider having to apply manual or foot pressure to the brakes.

Using the inertial measurement unit (IMU) to measure the slope angle and wheel speed sensors, the system communicates directly with the ABS control unit. When the motorcycle comes to a stop on a slope, the hydraulic unit maintains pressure in the braking system (typically on the rear caliper). As soon as the engine control unit (ECU) detects the throttle opening, the increase in engine torque, and the gradual slipping of the clutch, it automatically releases the hydraulic pressure to provide a smooth start, without jerks or the risk of rolling backward.

Depending on the manufacturer, the system is activated either automatically once a minimum gradient is detected, or manually by applying light pressure to the front brake lever while the motorcycle is at a standstill.

The HISS (Honda Ignition Security System) is the electronic immobilizer system exclusive to Honda motorcycles. Introduced in the late 1990s to combat theft, this device prevents the engine from starting by directly locking the ignition and fuel injection if the inserted key is not recognized by the engine control unit (ECU).

Each original key contains a transponder chip with a unique cryptographic code. When the ignition is turned on, a ring-shaped antenna around the ignition switch reads this code and transmits it to the ECU. If the code matches, the ECU unlocks the engine functions; otherwise, the engine will not start. This direct electronic link renders simply bypassing the ignition switch wires (hotwiring) completely ineffective for starting the motorcycle.

Visually indicated by a red warning light on the instrument panel, the HISS system provides highly effective passive protection but imposes a significant practical limitation: the loss of all coded keys requires the replacement or complex reprogramming of the ECU.

The HMAS (Honda Multi-Action System) is a hydraulic suspension technology (front fork and rear shock absorber) developed by Honda in the late 1980s to optimize handling and comfort on its sport and touring models.

Unlike basic conventional suspensions that use simple bores—whose hydraulic resistance becomes too stiff during rapid impacts and too soft at low speeds— the HMAS is based on a cartridge design equipped with a piston featuring a stack of flexible shims (shim stacks).

Technical Operation

• Control Based on Compression Speed: The system regulates oil flow based on the speed of the suspension piston’s movement rather than engine RPM or the motorcycle’s speed.
• Low piston speed (rider movements, load transfers during braking or acceleration): Oil flows through finely calibrated channels. Hydraulic damping is firm, which limits fork dive and maintains the motorcycle’s stability.
• High piston speed (hard impacts, potholes, road irregularities): The increased oil pressure causes the metal valves to deform slightly, opening a wider flow path. The shock absorber absorbs the impact instantly without transmitting a jolt to the wrists or spine.

H.O.G. (Harley Owners Group) is the official owners' club created by Harley-Davidson in 1983 to bring its community together and strengthen brand loyalty.

Conceived as a community strategy unprecedented in the motorcycle industry, H.O.G. now has nearly one million members worldwide. The organization is structured around a network of local chapters, each of which must be affiliated with and sponsored by an authorized dealership. The club offers its members a range of services and benefits: dedicated roadside assistance, exclusive access to major gatherings and private events, a dedicated magazine (H.O.G. Magazine), as well as a rewards system and embroidered items (patches and pins) recognizing mileage traveled.

Beyond logistical services, H.O.G. is the primary vehicle for the lifestyle and sense of belonging promoted by the Milwaukee-based brand. By transforming the purchase of a vehicle into membership in a true global community, this model has become a textbook example of marketing when it comes to customer loyalty.

Honda Racing Corporation (HRC) is Honda’s specialized subsidiary and official racing division. Founded in 1982 to centralize the brand's racing efforts, HRC develops and operates factory-backed machines competing at the highest international levels, notably in MotoGP, Rally Raid (Dakar), MXGP, and Trial (as well as Formula 1 since the merger of the auto and motorcycle divisions).

As a cutting-edge technology laboratory, this entity tests major engineering innovations under extreme conditions—such as oval-piston engines, Seamless transmissions, PGM-FI electronic fuel injection, and advanced aerodynamics—before transferring this expertise to iconic production models (RC30, RC45, CBR1000RR-R Fireblade, and RC213V-S).

Recognizable by its logo and historic tricolor livery (blue, white, red), HRC also markets racing parts kits and machines for private teams.

the HSTC system controls the torque delivered by the motor in 2 ways: when the control unit detects acceleration of the rear wheel (and deceleration of the front wheel), it reduces the opening of the TBW - and therefore the power - allowing the front wheel to remain in contact with the ground. This makes it possible to open the throttle to the maximum, without the risk of pitching up (rear wheel).

the second method used by the HSTC detects the angle of inclination of the motorcycle. The inertial measurement unit (IMU) housed under the seat discerns the speed and acceleration of the chassis in yaw and roll, as well as in longitudinal, transverse and lateral directions. The IMU then deduces the angle of inclination to control engine torque and maintain rear-wheel traction at the right level.

the computer logic used by the IMU is based on the same detection technologies developed for the ASIMO humanoid robot, enabling the most precise calculations possible.

the HTSC offers 9 levels of intervention (+ deactivation) to suit the rider's preferences, while User Modes 1 and 2 enable specific settings, even while driving.

The Idling Stop System automatically switches the engine off at traffic lights and other brief stops, eliminating wasteful fuel consumption.

When the Idling Stop System is switched on, it automatically turns the engine off and on for you when you stop and start up. This results in a fuel saving of approximately 7%, compared to when the system is not in operation (according to Honda testing using ECE R40 mode).

An inertial unit is an instrument used in navigation, capable of integrating the movements of a moving object to estimate its orientation, linear velocity and position. The estimated position is relative to the starting point or to the last reference point.

An IMU measures movements in 3 dimensions. It provides ultra-precise data on :
- Acceleration (forward/backward, up/down, lateral)
- Rotation (roll, pitch, yaw)
- Inclination (angle of turn or lateral inclination)

To achieve this, it uses an accelerometer to measure linear acceleration on 3 axes, and a gyroscope to measure rotation speed on 3 axes.

The IMU provides greater precision for steering aids and greater functionality:
- aBS can become reactive when cornering
- Headlights can light up curves
- Traction control releases power according to angle, not just wheel speed difference.
- and other interventions on the shifter, suspension, glide, pitching, etc.

Kawasaki Advanced Coactive-braking Technology (K-ACT or K-ACT ABS) is an intelligent combined braking and electronic anti-lock braking system designed by Kawasaki primarily for its grand touring motorcycles (such as the 1400 GTR or the VN 1700 Voyager series).

Unlike a traditional mechanical linkage, K-ACT uses an ECU-controlled hydraulic unit to dynamically interconnect the front and rear brakes. When the rider operates the handlebar lever or foot pedal, the system analyzes the motorcycle’s speed, the applied force, and the chassis dynamics to instantly distribute the ideal hydraulic pressure to each caliper. This co-active pressure distribution prevents excessive fork dive and rear-end lift, keeping the bike perfectly stable, even when fully loaded with a passenger and luggage.

The KCMF is a device that continuously monitors engine data (RPM, throttle opening, etc.) and chassis data (lean angle, wheel speed, brake pressure, etc.) during all phases of a turn (entry, apex, exit). Its main role is to finely modulate engine power and braking force to make the transitions between acceleration and braking, and then during re-acceleration, as smooth and fluid as possible. By adjusting these parameters, the KCMF assists the rider in maintaining the ideal trajectory throughout the turn, thereby optimizing stability and performance.

To accomplish its mission, KCMF supervises and coordinates several of the motorcycle's electronic aids (if present):

• KTRC (Kawasaki Traction Control): Management of wheel spin, front wheel lift (anti-wheelie), and sliding.
• KLCM (Kawasaki Launch Control Mode): Static start assist.
• KIBS (Kawasaki Intelligent anti-lock Brake System): Intelligent ABS braking system that includes fork dive control.
• KEBC (Kawasaki Engine Brake Control): Engine brake control

The Kawasaki Engine Brake Control (KEBC) is an electronic assist system developed by Kawasaki to regulate and customize the intensity of engine braking during deceleration and downshifting.

When the throttle is suddenly closed or a hard downshift is performed, the mechanical drag of a high-performance engine can cause wheel spin, rear-wheel slippage, or chassis instability when entering a turn. The KEBC resolves this issue by communicating directly with the engine control unit (ECU) and the electronic throttle control (Ride-by-Wire). By analyzing engine speed, gear selection, and wheel speed, the electronic system commands a very slight opening of the throttle valves to inject a thin stream of air, thereby reducing the resistance offered by the engine.

The Kawasaki Electronic Control Suspension (KECS) is an electronically controlled semi-active suspension system developed by Kawasaki in partnership with Showa. It adjusts the compression and rebound damping of the fork and rear shock absorber in real time to optimize the motorcycle’s handling and stability in response to road imperfections and load transfers.

Its operation relies on exceptionally fast response times: thanks to direct-actuated solenoid valves integrated into the suspension components (Showa BFF or cartridge fork, and BFRC lite or Uni-Trak rear shock), KECS adjusts oil flow in just 1 millisecond. The control unit adapts damping by continuously cross-referencing data from stroke sensors integrated into the fork and shock absorber, the inertial measurement unit (IMU), wheel speed sensors, and the braking system.

Integrated with the Riding Modes, the KECS modifies suspension firmness according to the selected mode (Sport, Road, Rain, Rider). On models such as the Versys 1000 / 1100 SE, it incorporates Showa’s Skyhook dynamic control to smooth out body roll, as well as electronic adjustment of the rear spring preload directly from the instrument panel (solo, solo with luggage, two-up, two-up with luggage).

KIBS (Kawasaki Intelligent anti-lock Brake System) is a high-precision braking system designed specifically for supersport models, offering highly efficient braking while retaining a natural feel.

KIPASS (Kawasaki Intelligent Proximity Activation Start System) is the keyless ignition and remote locking system developed by Kawasaki.

It relies on an RFID transponder (electronic key) that the rider keeps in their pocket. As soon as the rider approaches the motorcycle (within about 1 or 2 meters), the motorcycle’s antennas detect the encrypted radio signal and unlock the immobilizer as well as the main ignition switch.
KIPASS also controls the unlocking of the fuel cap and the storage compartments.

designed to help riders maximize acceleration during standing starts, the KLCM electronically regulates engine power to prevent the rear wheel from spinning at the start. The rider can select one of 3 modes, each offering a different degree of assistance. Each of the 3 modes allows the rider to start with the throttle wide open.when the clutch lever is pressed and the system is activated, engine speed is automatically limited as long as the throttle is engaged. As soon as the clutch is released, engine speed increases, but power is regulated to prevent the rear wheel from spinning and the front wheel from lifting (in mode 1, the least intrusive, the front wheel can lift slightly). The system deactivates automatically at 150 km/h or when the rider engages 3rd gear.

Credits : Kawasaki

The KQS (Kawasaki Quick Shifter) is the clutchless quick-shift system developed by Kawasaki. It allows you to shift up (and down on modern bidirectional versions) without touching the clutch lever or closing the throttle.

Technical Operation

• Shift lever force sensor: A sensor (piezoelectric or contact-type) integrated into the gear selector measures the pressure or tension exerted by the rider’s foot on the shift lever.
• Ultra-fast signal sent to the ECU: As soon as physical force is detected on the shifter, the sensor transmits the information to the central computer.
• Electronic transmission control:
  - When upshifting: The ECU interrupts ignition or fuel injection for a few milliseconds. This micro-interruption instantly relieves the mechanical pressure between the gearbox gears, allowing the shift forks to smoothly lock into the higher gear with the foot still on the shifter.
  - When downshifting (Downshift / Auto-blipper): On dual-action versions, the ECU commands the Ride-by-Wire system to perform an automatic throttle blip (auto-blip) to realign the engine speed with the drive shaft speed, facilitating engagement of the lower gear without risking locking up the rear wheel.
• Torque Recovery: Ignition and fuel injection are re-engaged immediately after the gear is locked in, providing uninterrupted acceleration.

kTRC has been designed to prevent rear-wheel spin, which could lead to loss of motorcycle control. The system uses sensors to constantly monitor the rotational speeds of the front and rear wheels. When wheelspin is detected, engine power is reduced so that the rear wheel can regain the grip necessary to keep the machine stable.
KTRC acts on 3 engine parameters to modulate power and enable the rear wheel to regain grip: the volume of air admitted (via the secondary butterflies), the quantity of fuel admitted and ignition. This is why the system is so unobtrusive, resulting in a very natural feel for power modulation. The rider is not even aware that the KTRC system is regulating power to allow the rear wheel to regain grip, even though it informs him of its operation by deliberately delaying its action for a few moments and lighting up the appropriate signal on the dashboard.

News credit: Kawasaki