Motor Voltage For Trike
According to the performance data, the motor produces over 3 kW (actually 3.7 kW @ around 90% efficiency) at 72V and 60A. Pretty impressive!

If you cut the voltage in half, you will cut the available power by at least half as well, because you still won't be able to exceed 60A &mdash; this limit is set by the resistance and power dissipation of the windings.