2-speeds don't have much of an effect on an electric motor. Nitros benefit from a 2-speed because engines create maximum power at high rpm. The 2-speed is there to provide an easier first gear, so the car can accelerate more quickly. The transmission doesn't really increase top speed, it just decreases the time required to reach top speed. Electric motors develop maximum power at low rpm and don't need an easy first gear to accelerate well. At high rpm, an electric motor doesn't have the power to exploit an upshift to a lower gear ratio. Two-speed trannies aren't often seen in electric vehicles simply because the minor potential for performance gain is usually outweighed by the cost and complexity of a 2-speed system.