Float shifting or floating gears, also called "slip shifting", "dead sticking" or "bang shifting", is the process of changing gears, in typically a
non-synchronous transmission, without depressing the
clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
. Shifting in this manner is also used with synchronous manual transmissions, particularly after a clutch failure, to prevent destroying the
syncromeshes with the power of the engine.
The most skillful drivers can shift non-synchronous transmissions without using the clutch by bringing the engine to exactly the right RPM in neutral before attempting to complete a shift. If done improperly, it can damage or destroy a transmission. Some
truck
A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame construction ...
(lorry)
drivers use this technique with the higher gears when at work. The technique is sometimes also used on
motorcycle
A motorcycle (motorbike, bike, or trike (if three-wheeled)) is a two or three-wheeled motor vehicle steered by a handlebar. Motorcycle design varies greatly to suit a range of different purposes: long-distance travel, commuting, cruising ...
s,
The Truth About Clutchless Shifting , Motorcyclist
/ref> but has largely been replaced by quickshifter
A quickshifter (or quick shifter) is a device that eliminates the need to use the clutch or throttle when shifting gears on a manual transmission. This can increase the safety and comfort of the vehicle and allow for faster gear shifting (usually s ...
s for competitive use.
Technique
To upshift, the driver should first bring the engine up to speed. They must then shift to neutral and apply moderate pressure to the gear stick
A gear stick (rarely spelled ''gearstick''), gear lever (both UK English), gearshift or shifter (both U.S. English), more formally known as a transmission lever, is a metal lever attached to the transmission of an automobile. The term ''gear sti ...
, and when the RPM
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
s are low enough, the shifter will slide into place. The same technique for shifting down is used except that the accelerator must have some pressure applied to it to bring the RPMs up to match the speed of that gear at that wheel speed.
Pros and cons
Float shifting can reduce clutch and synchromesh wear because they are simply not used in the process of selecting a gear. Contrarily, improper engagement of a gear (when the engine and transmission speeds aren't matched) can cause damage to the gears by physically grinding them together due to a difference in speed. Float shifting also takes longer due to the engine RPM needing to decrease and but can be more rewarding since it requires more skill to accomplish successfully.
References
Driving techniques
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