Wheel Rim Basic parameters

A wheel hub includes many parameters, and each parameter will affect the use of the vehicle, so before refitting and maintaining the wheel hub, first confirm these parameters. 

size

In fact, the hub size is the diameter of the hub. We often hear people say 15 inch hub and 16 inch hub, among which 15 inch and 16 inch refer to the size (diameter) of the hub. Generally, in the car, if the hub size is large and the tire flat ratio is high, it can play a very good visual tension effect, and it will also increase in the stability of vehicle control, but the following is the additional problem of increased fuel consumption.

width

The width of wheel hub is also known as J value. The width of wheel hub directly affects the selection of tires. For tires of the same size, the flat ratio and width of selected tires are different with different J values.

PCD and hole location

The professional name of PCD is pitch diameter, which refers to the diameter between the fixed bolts in the center of the hub. Generally, most of the holes in the hub are 5 bolts and 4 bolts, but the distances of the bolts are different, so we can often hear 4x103, 5x114.3 and 5x112. Taking 5x114.3 as an example, the PCD of this hub is 114.3mm, and the holes are 5 bolts. When choosing the hub, PCD is one of the most important parameters. For the sake of safety and stability, it is better to choose the same hub of PCD and the original vehicle for upgrading.

Offset distance

The distance between the fixing surface of the hub bolt and the geometric center line (the center line of the cross section of the hub) is simply the difference between the fixing base of the screw in the middle of the hub and the center point of the whole wheel rim. The common point is whether the hub is retracted or protruded after modification. For general cars, et value is positive, for a few vehicles and some jeeps, it is negative. For example, the offset value of a car is 40. If the hub of et45 is replaced, it will shrink into the wheel arch more visually than the original hub. Of course, the ET value not only affects the visual changes, but also relates to the steering characteristics and wheel alignment angle of the vehicle. The excessive offset value may cause the tire to wear abnormally, the bearing to wear easily, or even to be installed abnormally (the brake system and the wheel hub cannot rotate normally due to friction). In most cases, the same type of wheel of the same brand The hub will provide different et values to choose from. Before refitting, comprehensive factors should be considered. The safest situation is to keep the ET value of refitted hub the same as that of the original manufacturer without refitting the brake system.

Center hole

The center hole is the part used to fix the connection with the vehicle, that is, the position of the center of the hub and the concentric circle of the hub. The diameter and size here affect whether we can ensure that the geometric center of the wheel rim can be consistent with the geometric center of the hub when we install the hub (although the hub positioner can change the hole distance, there are risks in this modification, users need to try carefully).