In a railroad system a track is formed of ties positioned at predetermined intervals along the right of way, and supporting a pair of rails. Shoulders are disposed in pairs adjacent to the sides of each rail and are partially imbedded in the ties to limit the lateral movement of the rails and define the track gauge. Between each pair of shoulders there is provided a pad disposed under the respective rail. Insulators are provided between the sides of the pad and a respective shoulder. Over time, friction between the insulators and the shoulders may cause excessive wear. This wear is compensated by one or more shims attached to the shoulders by a strong adhesive.