Basic parameters of wheel hub
Size
The size of the wheel hub is actually the diameter of the wheel hub. We can often hear people say 15 inch wheel hubs and 16 inch wheel hubs. Among them, 15 and 16 inch refer to the size (diameter) of the wheel hub. Generally, on cars, if the wheel hub size is large and the tire flat ratio is high, it can play a very good tension effect visually, and the stability of vehicle handling will also be increased. However, the additional problem of increased fuel consumption will follow.
Width
The width of the wheel hub is also commonly known as J value. The width of the wheel hub directly affects the selection of tires. For tires of the same size, different J values will lead to different flat ratios and widths.
PCD and hole location
The professional name of PCD is pitch circle diameter, which refers to the diameter between the fixing bolts in the center of the wheel hub. Most of the holes of a general wheel hub are 5 bolts and 4 bolts, and the distance between the bolts is different, so we can often hear 4x103, 5x114.3 and 5x112. Taking 5x114.3 as an example, it means that the PCD of this wheel hub is 114.3mm, and the holes are 5 bolts. When selecting the wheel hub, PCD is one of the most important parameters. For the sake of safety and stability, it is better to select the wheel hub with the same PCD as the original vehicle for upgrading.
Offset
English is offset, commonly known as et value, the distance between the hub bolt fixing surface and the geometric centerline (hub cross-sectional centerline). To put it simply, it is the difference between the screw fixing seat in the middle of the hub and the center point of the whole wheel rim. In common terms, it is whether the hub is retracted inward or protruded outward after modification. For ordinary cars, et value is positive, while for a few vehicles and some jeeps, it is negative. For example, the offset value of a car is 40. If the wheel hub of et45 is replaced, it will be visually more retracted into the wheel arch than the original wheel hub. Of course, the ET value not only affects the visual change, but also has a relationship with the vehicle's steering characteristics and wheel alignment angle. A large offset value may lead to abnormal wear of tires, easy wear of bearings, or even normal installation at all (the brake system and the wheel hub cannot rotate normally due to friction). In most cases, the same type of wheel hub of the same brand will provide different et values to choose from, Comprehensive factors should be considered before refitting. The safest situation is to keep the ET value of the refitted wheel hub the same as that of the original factory without refitting the brake system.
Center hole
The central hole is the part used for fixed connection with the vehicle, that is, the position of the hub center and the concentric circle of the hub. The diameter here affects whether we can ensure that the geometric center of the wheel rim can coincide with the geometric center of the hub when we install the hub (although the hub positioner can change the hole distance, this modification has risks, and netizens should try it carefully).
