what is q factor

The Q factor, also known as the quality factor, is a dimensionless parameter that describes how underdamped an oscillator or resonator is. It is defined as the ratio of the initial energy stored in the resonator to the energy lost in one radian of the cycle of oscillation. A higher Q factor indicates a lower rate of energy loss, meaning that the oscillations die out more slowly. In the context of cycling, Q-factor refers to the width of the crankset, specifically the distance between the outside of one crank arm and the other, measured laterally through the midline of the bottom bracket. This measurement is important for rider compatibility and can affect stance and pedal efficiency. The Q factor is a critical parameter in understanding the behavior of resonant circuits or systems in various applications, including electronics, mechanical systems, and cycling.