How does a pre-selector gearbox work?

A pre-selector gearbox is a type of transmission system that allows the driver to select the desired gear in advance, typically using a lever or knob. When the driver engages the next gear, the system uses a mechanism, often involving a cone and clutch arrangement, to synchronize the selected gear with the engine speed before engaging it. This allows for smoother gear changes and can help reduce the load on the drivetrain. As a result, the pre-selector gearbox can provide a more efficient and responsive driving experience, particularly in applications like racing or heavy machinery.