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
Rim (wheel) object. Some authors are careful to use "rim" for only the outer portion of a wheel, where the tire mounts, just as the rim of a coffee cup or a meteor crater does not refer to the entire object. One engineering text says "alloy wheels [are] often incorrectly called aluminum rims". Others use "rim" to mean the entire metal part to which the tire mounts, because the rim and the wheel are often cast or stamped from a single piece of metal instead of being distinct as with wire wheels. At the same time, "wheel" may refer to the entire