At the highest level, electric motorcycles function in much the same way as any conventional internal combustion bike. They all require some form of energy storage, a way to control the release of that energy, and a way to convert that energy into rotational motion at the wheel.
In a nutshell, the differentiating factors between battery-electric and internal combustion vehicles are that:
- Battery-electric vehicles store chemical energy in a battery pack, rather than liquid energy as fuel in a tank.
- This energy is delivered to the motor through an electrical circuit, controlled by a rapidly switching motor controller, rather than to a combustion chamber, in which fuel is injected and ignited by a spark.
- The energy is used to create an electromagnetic field, which acts on another field produced by magnets attached to the rotating shaft of the motor, rather than an explosion that forcibly drives a piston.
In understanding these fundamental differences between combustion and electric systems, we begin to see why electric vehicles can produce such instantaneous and extremely high levels of torque.
The first thing to note is that electromagnetic energy travels through a circuit at close to the speed of light – so the generation of torque doesn’t need to wait for fuel to be fed through a line, or for that fuel to combust. Because this energy is also controlled electrically rather than mechanically, it can be done so much more quickly and precisely than a combustion engine.
In addition, the torque produced by an electric motor is primarily correlated to the amount of current flowing through its stator coils – or ‘windings’ – which create the magnetic field. Provided the current is available, it can be instantly sent through the windings to achieve the required torque – regardless of the motor’s RPM.
On the other hand, the torque produced by a petrol motor is derived from a combustion event, in which the efficiency can vary considerably based on the RPM that the motor is turning. Because the efficiency drops off at low RPMs, the torque produced is also less than it would be when the motor is operating in its ideal RPM range.
So when you hear people talk about the instant torque of the Savic Motorcycles C-Series, this is how we’re able to achieve it.