In one example, a bearing or transmission has an outer race that extends circumferentially about a central axis. An inner race is disposed within the outer race and extends circumferentially about the central axis so as to be coaxial with the outer race. A plurality of load-bearing rolling elements are disposed between the inner race and the outer race, and are spaced circumferentially from one another so as to not contact one another. A plurality of separator rolling elements are disposed within the outer race. Each separator rolling element is disposed between a respective pair of the load-bearing rolling elements such that the separator rolling element is in rolling contact with the load-bearing rolling elements of the respective pair. The load-bearing and separator rolling elements form a contiguous ring.