The wheel is an important component of the vehicle's running gear, which not only support the weight of the entire vehicle but also absorb road impacts and generate driving and braking forces through the tire's grip on the road surface, ensuring the normal operation of the vehicle. The structure of a wheel mainly includes the rim, spokes, hub, and tire. The terms rim, spokes, and hub may sound similar, which can confuse many car owners. Today, let's discuss the differences between them.

1. Rim

The rim, also known as the wheel disc, refers to the part of the wheel that installs and supports the tire around the periphery. Together with the spokes, it bears the load of the wheel and dissipates the heat generated by the tire.

The image above shows a common structure of the rim, which is strictly speaking a combination of the rim and spokes. Depending on the material used, many car owners directly refer to them as "steel wheels" or "aluminum wheels," indicating rims made of steel or aluminum. 

2. Spokes

Spokes refer to the parts of the wheel that connect the rim and the hub.

Based on the structure of the spokes, wheels can be divided into two types: web-type and spoke-type. Vehicles that frequently travel at high speeds often use multi-spoke designs, which provide good support and help to avoid or reduce deformation of the wheel during driving. On the other hand, vehicles that pursue lightweight characteristics on short-distance technical tracks often use fewer spokes, which have a unique exposed appearance.

The spokes and rim can be divided into one-piece, permanently connected, and detachable types.

 

3. Hub

The hub, commonly known as the "potato head," refers to the part that connects the wheel to the axle. It is mainly connected to the rim and axle with bolts or pins and also provides central support for the wheel.

In many places, the hub and rim are often confused, but they are actually two different parts. The rim is the part that installs and supports the tire around the wheel, while the hub is the cylindrical, metal part that supports the tire on the inner contour and is mounted on the axle, scientifically known as the "hub unit."