Quickshifter

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Quickshifter

A quickshifter (also called a quick shifter) is a device that lets you shift gears on a manual motorcycle without using the clutch or twisting the throttle. It makes gear changes faster and can increase safety and comfort, often performing shifts in under 50 milliseconds.

How it works
Most quickshifters use a microcontroller that detects a gear shift through a sensor. When a shift is detected, the system temporarily reduces engine load by cutting ignition or fuel, or by disengaging the clutch. This unloads the transmission so the engine speed can match the next gear and the gear can slip into place smoothly. Different systems sense the shift in different ways, but the goal is the same: a fast, smooth shift with less wear on the drivetrain.

Sensor types
- Mechanical sensors: mounted on the shift linkage and react to push or pull motions.
- Strain gauges: measure the force in either direction, offering flexible and often more accurate shift detection.
Microcontrollers (either inside the sensor system or in the quickshifter module or ECU) set the required shift direction and sensitivity. Electronic designs can be more reliable due to fewer moving parts.

Quick shift module
The control unit usually intervenes on ignition and/or fuel to reduce load during a shift. Older bikes often use a separate aftermarket module, while modern bikes rely on the engine’s own ECU to perform the calculations. Shifts can be nearly instantaneous, often in tens of milliseconds.

Transmission load control
During a shift the system unloads the engine and then restores the load after the shift, allowing the bike to continue accelerating smoothly. Some setups stagger the cut in two channels to prevent shocks to the drive chain. When tuned correctly, a quickshifter is gentler on the transmission than clutchless shifting without one.

Bi-directional quickshifter
Bi-directional quickshifters work for both upshifts and downshifts (also called auto blippers). Some quickshifters only do upshifts (mono-directional). Bikes with bi-directional systems include models from BMW, Kawasaki, Suzuki, Aprilia, KTM, and others.

See also
- Motorcycle transmission
- Traction control (TCS)
- Anti-lock braking system (ABS)
- Launch control
- Electronic stability control (ESC)
- Cruise control