About Quickshifters

What is a Quickshifter?

A quickshifter is a device that allows a rider to upshift without clutching or backing off the throttle. The rider still uses their foot to shift but relies on electronics to momentarily cut power to the engine. This power cut allows the current gear to release so that the next gear can be engaged. The clutch can still be used to feather shifts if the rider chooses.


Why Use an Inline Quickshifter?

An inline quickshifter is a device that installs inline with the shift rod that connects the shift lever at the foot to the shift lever at the engine. An important feature of inline quickshifters is that they are able to respond differently to upshifts and downshifts. During an upshift the inline quickshifter will trigger a power cut. During a downshift the inline quickshifter will not cut power. A power cut during a downshift can interfere with throttle blipping and for this reason an inline quickshifter is the preferred type to use.


Fuel Cut versus Spark Cut

A power cut is essential to a quickshift. The power cut can be accomplished by cutting fuel and/or cutting spark (aka ignition) to the engine. For carbureted engines there is no easy way to cut fuel so spark cut is the preferred method of cutting power. For fuel injected engines fuel cut is the preferred method of cutting power.

There are several reason why cutting fuel is preferred over cutting spark. When cutting spark the air and fuel continues to enter into the combustion chamber through the intake valves. In the absence of a spark the air fuel mixture behaves like an overly rich fuel mixture that can foul the spark plugs. After the air fuel mixture exits the combustion chamber it passes into the exhaust system where is can ignite and back fire. In extreme cases back fires can damage both the engine and exhaust system. Unburnt fuel can also damage catalytic converters, which are becoming standard equipment on most motorcycles.

All bike-specific Nextup Quickshifter Kits ship with OEM plugs that connect to the bikes fuel injectors. The plug-n-play harness is recommended for all applications except when the motorcycle has been fitted with a wet nitrous system.


What makes the Nextup Universal Quickshifter Kit universal?

The Nextup Universal Quickshifter Kit can be used on any fuel-injected or carburetted motorcycles with any number of spark plugs, ignition coils, or fuel injectors. Using the provided instructions and the basic wires harness the installer can wire the bike to cut either fuel or spark during the quickshift.

The kit includes a versatile rod kit that allows the customer to install it in one of six different ways. The rod kit uses M6 hardware which is the common size on European and Japanese motorcycles. Some motorcycles may use shift rods that have non-M6 threads one or both ends in which case an M6 adapter is required. Foot levers that connect directly to the engine must be converted to include a shift rod.