A quickshifter or quick shifter is a device that eliminates the need to use the

clutch A clutch is a mechanical device that allows an output shaft to be disconnected from a rotating input shaft. The clutch's input shaft is typically attached to a motor, while the clutch's output shaft is connected to the mechanism that does th ...

throttle A throttle is a mechanism by which fluid flow is managed by construction or obstruction. An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' ha ...

when shifting gears on a

manual transmission A manual transmission (MT), also known as manual gearbox, standard transmission (in Canadian English, Canada, British English, the United Kingdom and American English, the United States), or stick shift (in the United States), is a multi-speed ...

. This can increase the safety and comfort of the

vehicle A vehicle () is a machine designed for self-propulsion, usually to transport people, cargo, or both. The term "vehicle" typically refers to land vehicles such as human-powered land vehicle, human-powered vehicles (e.g. bicycles, tricycles, velo ...

and allow for faster gear shifting (usually shifting in less than 50 milliseconds) and is thus a popular performance enhancement for

motorcycles A motorcycle (motorbike, bike; uni (if one-wheeled); trike (if three-wheeled); quad (if four-wheeled)) is a lightweight private 1-to-2 passenger personal motor vehicle Steering, steered by a Motorcycle handlebar, handlebar from a saddle-style ...

Working mechanism

Almost all quickshifters for upshifts on motorcycles work on the same basis: a

microcontroller A microcontroller (MC, uC, or μC) or microcontroller unit (MCU) is a small computer on a single integrated circuit. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable input/output peripherals. Pro ...

detects the gear shift action via a sensor, calculates the shift timing, and momentarily cuts off the ignition, resulting in a reduction of the load at the

transmission Transmission or transmit may refer to: Science and technology * Power transmission ** Electric power transmission ** Transmission (mechanical device), technology that allows controlled application of power *** Automatic transmission *** Manual tra ...

allowing the engine speed to match the transmission speed of the next gear and permit the gear to slip (and engage) into place. However, the method of sensing and reducing the load can vary.

Sensor types

Typically, the sensor is mounted in a way that it is a functional part of the gear shift linkage. The shift action by the rider, results in an actuation force on the sensor. Depending on the shift linkage design the sensor specifically reacts either on a push or pull action. Mechanical, linear, sensors typically close a micro switch at a factory preset force level in one particular direction only. A more versatile sensor design uses a

strain gauge A strain gauge (also spelled strain gage) is a device used to measure Deformation (mechanics)#Strain, strain on an object. Invented by Edward E. Simmons and Arthur C. Ruge in 1938, the most common type of strain gauge consists of an Electrical in ...

to measure the level of the applied force in either direction. The design is typically linear (rod mounted) but can also be rotative (axle mounted). A dedicated micro controller, either purposely part of the sensor system alone or fully integrated in a quick shift module, normally has the flexibility to both set the required upshift direction (push / pull) and force sensitivity to detect the correct shift moment. In comparison with the mechanical type these relevant features ensure a more accurate, error free, shift detection for after-market applications, depending on rider preference, use case and, set correctly, reduce wear on the transmission gear selection system. Electronic sensor designs may be more complex and expensive but other than the above-mentioned advantages, may also be more reliable due to having no

moving parts Machines include both fixed and moving parts. The moving parts have controlled and constrained motions. Moving parts are machine components excluding any moving fluids, such as fuel, coolant or hydraulic fluid. Moving parts also do not include ...

Quick shift module

The control module generally intervenes on the ignition and/or fuel supply to reduce the load on the transmission while shifting. Often an after-market stand-alone module, separate from the

engine control unit An engine control unit (ECU), also called an engine control module (ECM), is a device that controls various subsystems of an internal combustion engine. Systems commonly controlled by an ECU include the fuel injection and ignition systems. The ...

(ECU), is used on older motorcycles. On modern motorcycles the engine management ECU itself performs the required calculations for the intervention. They can provide a near-perfect gear shift in tens of milliseconds.

Transmission load control

The load on the transmission is generally reduced (or "''unloaded''") by cutting off the ignition and/or fuel supply of the engine, or by disengaging the clutch. After the shift is completed, the engine torque i.e., load needs to return to the level prior to the shift to continue accelerating. To avoid a hard shock reaction on the chain drive, stand-alone modules can activate the cut cylinders in a staggered, controlled manner. To achieve this at least two separate control channels are required. Since the engine load is both reduced and reinstated in a precise and controlled manner (if tuned correctly) by the microcontroller, using a quickshifter is less damaging to the transmission than clutchless gear shifting without a quickshifter.

Bi-directional quickshifter

A ''bi-directional'' quickshifter is a quickshifter that works on both directions of gearshift - upshifts and downshifts. Many quickshifters are bi-directional (sometimes called ''auto blippers''), the term ''quickshifter'' alone is ambiguous since many are "mono-directional" quickshifters that only work in one direction, like the "Kawasaki Quick Shifter" (KQS) on the 2016

Kawasaki Ninja ZX-10R The Kawasaki Ninja ZX-10R is a motorcycle in the Kawasaki Ninja, Ninja sport bike series from the Japanese manufacturer Kawasaki Heavy Industries Motorcycle & Engine, Kawasaki, the successor to the Kawasaki Ninja ZX-9R, Ninja ZX-9R. It was origi ...

, and the 2015 H2/R or the QSS system used on a wide range of yamaha bikes, which works only for upshifting. Examples of performance-oriented motorcycles using a bi-directional quickshifter are the

BMW S1000RR BMW S1000RR is a race orientated sport bike initially made by BMW Motorrad to compete in the 2009 Superbike World Championship, that is now in commercial production. It was introduced in Munich in April 2008, and is powered by a Inline-four engi ...

and S1000R, 2017 ZX-10R and H2/R, Suzuki GSX-R1000/R, Aprilia Tuono, KTM Duke 390 etc.{{Cite news, url=https://www.cycleworld.com/2015/04/23/2016-aprilia-tuono-1100-v4-rr-first-ride-naked-sportbike-motorcycle-review-photos-specifications, title=2016 Aprilia Tuono 1100 V4 RR - FIRST RIDE, work=Cycle World, access-date=2017-10-06, language=en

References