According to the invention, simple measuring apparatus (10) is produced which is designed to ascertain if a so-called spring strut (50) appertaining to the front wheel suspension in a vehicle has been deformed or more specifically if it has been bent, the apparatus being designed to be used primarily on wheels equipped with disc brakes. The apparatus is used in situ, i.e. on a spring strut (50) mounted in place in the vehicle, and it is necessary only for the wheel to be removed, with the tire and rim, so that the disc brake (40) is exposed. The measuring apparatus consists of an upright (12) which is attached to a base part (14, 20) designed to be attached, preferably by means of permanent magnets (24, 26), to the outside of the brake disc (40). The upright (12) bears movably a measuring arm (30) equipped with a length scale and projecting out from the upright (12) at right angles to the plane of the brake disc (40); this arm also bears movably a pointer device ( 36) which can be made to seek out the center (60) of the upper fixing (55) of the spring strut (50) in the bodywork. After this adjustment, the perpendicular distance (a) from the fixing center (60) to the plane of the brake disc (40) can be read off on the scale on the measuring arm (30). From the knowledge of this distance it can be established whether or not the spring strut (50) has been deformed (bent).