Abstract: A bifurcated variable ratio drive transmission employs a pair of series connected differential gear stages. In a fist stage, torque flow from the engine output shaft is bifurcated into major and minor flow branches; in the second stage, the branches are combined. An engine output shaft drives an input ring gear of the first stage with the ring gear engaging a plurality of stepped planet gears. The planet gears in turn, drive both a sun gear of the first stage and a transfer ring gear. A major portion of torque flow is transmitted to the second stage through the transfer ring gear while a minor portion of torque flow passes from the sun gear of the first stage to the sun gear of the second stage. The transfer ring gear is fixed to a carrier to which are mounted pairs of radially spaced interengaged planet gears.