Figure 4: 3 Phase Induction Motor
For a given power rating, the volume and therefore weight of an electric motor are proportionately reduced. This combined with the desire to reduce unsprung mass on the vehicle suspension dictates using a high-speed motor, coupled to the rear wheel via some mechanical reduction gearing [7]. The UoN racing electric motorbike uses a 3 phase GVM Parker Hannafin permanent magnet motor which can reach speeds of up to 10,500Rpm as shown in figure 1 [9]. Other motor models could have been chosen but the GVM motors from Parker are specifically dedicated for Mobile applications and specially designed for rugged atmospheres and harsh environments for traction, pump, auxiliaries, and steering. These motors are brushless synchronous servomotors, with permanent magnets which are made of rare earth magnets allowing high-temperature operation, water or oil cooling system and a resolver/encoder speed sensor. The water cooling increases the torque density allowing a silent operation [9].

This motor is preferred due to features such as high efficiency due to no current in the rotor hence losses in the rotor are very low due to the absence of brushes, commuters or slip rings, high dynamic performances, high power density, wide speed range as speed control is easy and efficient, high precision, high motion quality, Low inertia, compact dimensions & robustness, large set of options & customization possibilities such as a wide variety of applications of high speed/power to low speed/power, can be used either as motor or generator and operating voltages available from 24 to 800 VDC [9].
Conclusion

There are many electric motorcycle manufacturers currently producing racing motorcycles with promising characteristics to rival their gasoline counterparts. Riding performances regarding acceleration, speed, and handling are already as good as any other motorcycle even in some cases, the electric motorcycles outperforming. The automotive industry is undergoing a radical transformation with 2025 as the next target date cited by manufacturers as a tipping point when everything from fuel, materials, and cost are set to change dramatically [13]. Certain technological issues are still present such as the range, battery, and motor sizes but as the technology rapidly changes through intensive research electric motorbikes might be in the market before 2025.

Electric racing superbikes have demonstrated that they can be raced at high speeds on demanding tracks to the point of even attracting racing corporations interested in investing in the technology. This a positive sign that electric motorcycles of the future will be exciting and fun to drive as well as environmentally friendly [7] with g