customized the axle of carbon fiber bicycle hubs for a professional cycling equipment manufacturer. Using aviation-grade 7075 aluminum alloy, through five-axis linkage CNC machining, the coaxiality error of the axle is controlled within 0.005 mm. With customized ceramic ball bearings, the rotation resistance of the hub is reduced by 40% and the battery life is increased by 15%. This hub helped the partner’s competition-level bicycles increase their usage rate in domestic amateur cycling events by 33%, and is highly sought after by many cycling enthusiasts.