The hub system of bicycle includes axle, bearing, hub and so on.

There are iron and aluminum flower drums in the profile of bicycle hubs. Iron flower drums are bicycle flower drums for cycling at home. Aluminum flower drums are relatively high-grade flower drums. They are used as flower drums for mountaineering bikes, performance bikes and road cars.

There are usually 32 hours and 36 hours in the circle, that is, the number of spokes. According to the number of spokes, there are three and five ways to arrange spokes.