Bike engines come in a multitude of different shapes and sizes. In essence they’re a gas pump, with the gas in this instance being a fuel-air mix. Their differing designs govern how much, and how fast, that volatile mix can be pumped through them, therefore dictating the ultimate power and torque levels the motor can produce. But just as importantly, many factors contribute to the way those two key performance-related figures are produced. Engines range from being relatively basic and simple, to hugely sophisticated with lots of complexity and clever variability to provide the most appropriate characteristics and features to suit a particular bike. Their final
