A hub contains many parameters, and each of these parameters will affect the use of the vehicle, so before you modify and maintain the wheel hub assembly, it is necessary to confirm these parameters.
The size of the hub is actually the diameter of the wheel hub assembly
. We often hear the statements 15 "hub, 16" hub and 15", 16 "refers to the size of the wheel hub assembly (diameter). In general, if the size of
wheel hub assembly is large and flat tire ratio is high in car, there will be visual tension and improved stability in vehicle handling but the problem of increased fuel consumption come together.
Wheel hub assembly width is also known as the J value. The wheel hub assembly width directly affects the choice of tires. The same size of tires with different J value, the choice of tire flat ratio and width is also different.
PCD and hole location
The professional name for PCD is pitch circle diameter, which is the diameter between the fixing bolts in the center of the wheel hub assembly. The average wheel hub assembly has 5 bolts and 4 bolts with different distances, so we often hear the statements of 4X103, 5x114.3, 5x112. Take 5x114.3 as an example, the PCD of this wheel hub assembly is 114.3mm with 5 bolts in the hole. When selecting the wheel hub assembly, it is better to choose the wheel hub assembly whose same PCD is the same as the original car for upgrading.
Its English name is offset. It is commonly known as ET value. It is the distance between the wheel hub assembly bolt fixing surface and the geometric centerline (hub transverse section centerline). Simply, it is the difference between the hub center screw seat and the center point of the entire rim. In layman's terms, the wheel hub assembly is modified to indent or protrude outward. For general cars, ET value is positive, but negative for a few vehicles and some jeeps. For example, the offset value of a car is 40. If the wheel hub assembly of the ET45 is replaced, it will shrink into the wheel arch more visually than the original wheel hub assembly. Of course, the ET value not only affects the visual changes, but also relates to the steering characteristics and wheel positioning Angle of the vehicle. Excessive offset may result in abnormal tire wear, bearing wear, or even failure to install properly. Comprehensive factors should be considered before modification. The safest situation is to keep the ET value of the modified wheel hub assembly the same as that of the original factory on the premise of not modifying the brake system.
The center hole is the part that is used for the fixed connection with the vehicle, the location of the wheel hub assembly center and the concentric circle of the wheel hub assembly. The diameter size here affects whether we can install the wheel hub assembly to ensure that the geometric center of the rim can match the geometric center of the wheel hub assembly.