Bicycle hub with protective structure

A bicycle hub with protective structure includes a hub cassette (1) and at least one protective member (2). The hub cassette (1) has a driving portion (12) and a shell portion (11) connected to the driving portion (12). The shell portion (11) has a plurality of ribs (14) integrally formed on an outer periphery of the shell portion (11) and extending axially. The protective member (2) is made of harder material than that of the ribs (14). The protective member (2) has a U-shaped cross section and defines a top wall (23) and two side walls (22). The top wall (23) and the two side walls (22) define an engaging groove (21). Specifically, an inner angle of the engaging groove (21) between the top wall (23) and each of the side walls (22) is an acute angle originally. Each of the two side walls (22) of the protective member (2) is flexible relative to the top wall (23) of the protective member (2) so as to clamp two lateral walls of the associated rib (14).