The invention relates to a railroad car truck in which the side frames are carried inboard of the wheels on supports that are stationary relative to the side frames. The side frames are provided with spring seats that are substantially aligned with the planes of the wheels on either side of the truck and support through spring groups a bolster of special design that supports the weight of the car body at two points on either side of the bolster, which points are aligned with the respective spring groups. The truck bolster is pivoted to the car body bolster by the usual kingpin, but the coupling arrangement involved is such that none of the body weight is supported at the customary center plate area of the bolster, which area is eliminated in the present truck. The truck bolster at its midportion includes a socket structure into which a projection of the body bolster fits for applying longitudinally and laterally acting forces to the bolster from which they are transferred to the side frames through suitable engaging surfaces. In one form of the invention, the side frames are mounted on tubular housings for the axles, which housings are journalled relative to the wheels through special roller bearing or friction bearing arrangements that are herein disclosed. In another form of the invention, the side frames are mounted directly on the axles, which are stationary relative thereto, and which have the truck wheels journalled on the respective ends through a special friction type bearing arrangement, with the result that the truck wheels rotate independently of each other.