Development of a New Bicycle Drive Hub

Drive hubs are a crucial component for any bicycle, as they are responsible for transmitting the power generated by the pedals to the bicycle wheels. There are two main types of drive hubs on the market, inboard and outboard. Inner hubs are more commonly used on city and hybrid bikes, while outer hubs are more common on road and mountain bikes. This work focuses on the freehub type internal gear drive hub. In a bicycle transmission system, the movement generated by the pedals is transmitted to the rear wheel of the bicycle through a series of gears and chain that allow the cyclist to adjust the torque and speed of the bicycle. The fundamental mechanism in this system is the rear wheel hub, which allows the rear wheel to rotate freely when there is no force applied to the pedals and accepts torque in the opposite situation. This mechanism can be either freehub or freewheel type. The way the gearing is done in the freehub is patented in two main processes, the ratchet, and the pawl. The system developed in this work is based on the ratchet scheme but contains permanent magnets instead of springs, which makes it smaller and less subject to material fatigue problems. In this design, the coupling movement is carried out by sliding in the 22 teeth axial spline on a radial toothed ring with 80 contact points, which mesh with a twin fixed to the wheel hub.