Bicycle wheel metal or carbon fiber rim which holds a pneumatic rubber tire. A hub is the center part of a bicycle wheel. It consists of an axle, bearings and a hub shell. The hub shell typically has two machined metal flanges to which spokes can be attached. Hub shells can be one-piece with press-in cartridge or free bearings or, in the case of older designs, the flanges may be affixed to a separate hub shell. The axle is attached to dropouts on the fork or the frame. The axle can attach using a: Modern bicycles have adopted standard axle spacing: the
Rim (wheel) millennium BC, an iron rim was introduced around the wooden wheels of chariots to improve longevity on rough surfaces. A standard automotive steel wheel rim is made from rectangular sheet metal. The metal plate is bent to produce a cylindrical sleeve, and then the two free edges of the sleeve are welded together. At least one cylindrical flow spinning operation is carried out to obtain the desired thickness profile of the sleeve—and the desired angle of inclination relative to the axial direction in the zone for the outer seat. The sleeve is then shaped to obtain the rims on each