A balanced split sun assembly with an integrated differential mechanism allows power to be transferred from a sun assembly to a plurality of ball planets, or allows power to be transferred from a plurality of ball planets to a sun assembly, while minimizing sliding, spin, axial pull, or other unwanted effects on the sun assembly. A differential mechanism, including offset mechanisms, allows torque to be divided between multiple split sun rolling elements. Variations in design of a split sun assembly allow for ease of manufacture, ease of assembly, and ease of adjustment.