Abstract: Spring modules for an adjustable sleeping system. At least some of the example embodiments are spring modules comprising: a spring rail, and a plurality of adjustable spring assemblies spaced along the length of the spring rail. Each adjustable spring assembly may comprise: a motor with a stator coupled to the spring rail via a load cell, a lead screw coupled to a rotor of the motor, and the lead screw extending above an upper surface of the spring rail, a spring plate coupled to the lead screw, and a main spring coupled to the spring plate. A tubular sock disposed over the main spring, and a compliant insert can be disposed between adjacent main springs to inhibit side loading and maintain the main spring in upright relation with the spring rail.