Water wheel a chain basket (German: Kettenkorb) on the axle of the wheel. It is essential that the wheel have braking equipment to be able to stop the wheel (known as a braking wheel). The oldest known drawing of a reversible water wheel was by Georgius Agricola and dates to 1556. Two early improvements were suspension wheels and rim gearing. Suspension wheels are constructed in the same manner as a bicycle wheel, the rim being supported under tension from the hub- this led to larger lighter wheels than the former design where the heavy spokes were under compression. Rim-gearing entailed adding a
Wheel hub motor designs have minimized the electrical steel content of the motor by using a coreless design with Litz wire coil windings to reduce eddy current losses. This significantly reduces wheel motor weight and therefore unsprung weight. Another method used is to replace the cast iron friction brake assembly with a wheel motor assembly of similar weight. This results in no net gain in unsprung weight and provides a car capable of braking up to 1G. A good example of this is the Michelin Active Wheel motor as fitted to the Heuliez Will, the first electric car with an Active Wheel drive,