PURPOSE: To select out freely a fitting position of a steering angle detector in connection with a steering mechanism, by detecting an actual steering angle through calculation of variations between information on the neutral position calculated out and the one on a current steering angle, using a calculating measure of a steering angle.

CONSTITUTION: A microcomputer 16 works for both a steering-angle-detecting unit 21 and a driving-controller 22 used for shock-absorbers 7, 8 with variable damping power. The detecting unit 21 contains a measure 23 for judging steering directions on the basis of detecting signals D1, D2 from a detector 3, a calculating measure 24 for up-down-counting, depending on the results of the above judgements, an averaging measure 25 and lastly a measure 26 for calculating steering angles. While information (θc) on a neutral position is stored in a memory device by the averaging measure 25, the variation between the information (θc) and the steering angle (θo) of the calculating measure 24 at the same time is calculated out by the steering angle calculating measure 26, so that the information (θ) of the steering angle detection, including information on steering directions at the time of actual operation of the steering mechanism can be obtained.