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
Wheel hub motor in Paris in 1900 and created a sensation in the young automobile world. In the following years, 300 Lohner Porsches were made and sold to wealthy buyers. Eventually the growth in power of the gasoline engine overtook the power of the electric wheel hub motors and this made up for any losses through a transmission. As a result, autos moved to gasoline engines with transmissions, but they were never as efficient as electric wheel hub motors. Several concept cars have been developed using in-wheel motors: Hub motor electromagnetic fields are supplied to the stationary windings of the motor. The outer