PURPOSE: To always secure proper damping characteristics in a motorcycle damper to control damping force through the exciting current of a linear solenoid by correcting reference exciting current based on the position and speed of a piston using the physical quantity of heat generated by the damper to control the exciting current.

CONSTITUTION: A motorcycle 10 has a cushion unit 16 composed of a damper 18 and a coil spring 20. In this case, means 100, 102 compute the position and speed of a piston on an output given by a detecting means 26 for a stroke of the cushion unit 16, namely the position of the piston respectively. A means 106 computes physical quantity corresponding to heat generated by the damper 18. A means 104 stores the reference exciting current in the direction of piston expansion and contraction, and a means 108 stores the correction value of the reference exciting current for the physical quantity. The reference exciting current is corrected on the same correction value to make a means 110 compute the final exciting current, which is supplied to a linear solenoid by a means 112.