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
Wheelbuilding a convention, if the hub has a maker's label on its barrel, for the label to face (and be readable through) the valve hole. See Gerd Schraner for methodology. The rim labels should be readable from the right-hand side (drive side) of the bicycle. The hub labels should face in the same direction front and rear (generally so they are readable from the seat), this means that even an undished, symmetrical front wheel has to be laced to the rim the "proper" way round, if perfection is the aim. Wheelbuilding Wheelbuilding is the process of assembling wire wheels (generally a