原文:A free hub, which integrates a freewheel mechanism and a hub, features both compact size and light weight. The innovation made it easier to replace sprockets, and increased the rigidity and durability of axles. 百度翻译: 自由轮毂集自由轮机构和轮毂于一体,具有体积小、重量轻的特点。这一创新使得更换链轮更加容易,并提高了车轴的刚性和耐用性。