A transmission for transferring torque from a prime mover includes a first input shaft adapted to be driven by the prime mover, a second input shaft, an output shaft and an epicyclic gearset. The gearset includes a ring gear being driven by the first input shaft, pinion gears being driven by the ring gear, a sun gear driven by the second input shaft and driving the pinion gears, and a carrier driving the output shaft. A reaction motor drives the second input shaft. A controller controls the reaction motor to vary the speed of the second input shaft and define a gear ratio between the first input shaft and the output shaft based on the second input shaft speed.