This video explains the working mechanisms involved in a motorcycle transmission through relevant animations. Motorcycle gearbox is a series of gear steps that help to change torque and rpm of a wheel depending on the different conditions.
It is a constant mesh sequential transmission system. In Constant Mesh Transmission system, all gears remains constantly meshed with each corresponding gear mates at all times.
The motorcycle transmission delivers power to the rear wheel through a series of structures that include the gearset, the clutch and the drive system.Most manual motorcycle gearboxes have “constant mesh” gears which are always mated but may rotate freely on a shaft until locked by a toothed sliding collar or “dog clutch”.
Since the gears are always rotating and can only be accessed sequentially, synchromesh is not generally needed. To save space, both shafts may contain a mixture of fixed and free-spinning gears, with some gears built into the sliding parts.