According to the invention, there is provided a steering
damper (10) in which the interior of a cylinder (12) is divided into two oil chambers (A), (B) by a
piston (14) which slides in the cylinder (12) as a steering operation takes place, an oil hole (15) is formed in the
piston (14) for providing a communication between the two oil chambers (A), (B) and a bypass passageway (16) is provided for allowing oil in one (A or B) of the oil chambers to flow into the other oil chamber (B or A) by bypassing the oil hole (15), the motorcycle steering
damper being characterized in that a subsidiary chamber (17) is defined at an intermediate position along the length of the bypass passageway (16), and in that a check ball (18) is provided in the subsidiary chamber (17), the check ball is adapted to move so as to close the bypass passageway (16) when a steering speed exceeds a predetermined value and a
differential pressure between the two oil chambers reaches or exceeds a certain value. Consequently, according to the invention, the mechanical operation of the motorcycle steering
damper (10) can be ensured without needing an
electrical control, and the vibration of a front wheel
system due to disturbance can be suppressed while attempting to reduce the production costs by decreasing the number of components involved and to secure high reliability.