Nowadays, many people are wondering what to replace with big and foreign wheels before they get their cars. In the eyes of the “Appearance Party”, the wheel hub is an important factor affecting the appearance of a car. However, the wheel hub is a seemingly appearance part, but it is actually closely related to the performance and safety of the car. If you only change the wheel hub for good-looking and cool, you may lose more than the gain in the end.
First of all, the hub is not as big as possible.
When the tire outer diameter remains the same, it is necessary to change the tire with a higher aspect ratio if you want to change a larger wheel. As a result, the lateral swing of the car is small, the car will be more stable when driving, and the feeling when cornering is also Lighter. But the price is that the shock absorption performance is greatly weakened, a small bump will be clearly transmitted into the car, and the comfort will definitely be greatly reduced. In addition, the flat and thin tires have relatively weak resistance to external forces, and are vulnerable to damage especially when stiffened by sharp objects.
For most people living in cities, there is not much chance of drag racing. If it is purely for appearance, it feels a bit “silly”. Generally speaking, it is most appropriate to increase one or two sizes according to the original wheel hub.
Second, not all big wheels can improve performance.
Many people think that widening the tires with large wheels will improve performance. This view is wrong. The size of the tire and wheel hub will directly affect the inertia of the wheel. If the inertia increases, it affects both acceleration and braking. If you want to greatly improve performance while increasing the size of the wheel hub, you must choose lighter wheels as much as possible.
It is especially important to note here that when the total mass of the wheel (wheel hub and tire) is the same, the larger the wheel hub, the worse the performance. For example, a wheel with a 16-inch hub weighs 30 kg, and a wheel with a 17-inch hub weighs 30 kg. From a general point of view, the weight is the same, and the inertia is the same. But this is not the case. The 17-inch wheel tires will be flatter, and the weight will be more concentrated on the outside of the wheel. When rotating at high speed, the inertia will be greater and the performance will be reduced.
In this case, the 17-inch wheels will have lower performance than the 16-inch wheels. The only solution is to continue to reduce the weight of the entire wheel and choose lighter wheels.
Third, the shape of the wheel itself will also affect the performance of the car
If the shape of a hub is such that the weight is concentrated in the center of the hub, then when the wheel rotates, the inertia generated is smaller; on the contrary, if the weight of a hub is concentrated on the outside of the hub, the inertia generated will be greater. Therefore, when choosing a wheel hub, it depends not only on the total weight of the hub, but also on where the weight is distributed. The farther the weight is from the center, the worse the performance.
Fourth, confirm the hub parameters before changing the hub
A wheel hub includes many parameters, and each parameter will affect the use of the vehicle, so before modifying and maintaining the wheel hub, you must first confirm these parameters.
1. Wheel size: In fact, it is the diameter of the wheel hub. We often hear people say 15-inch wheels and 16-inch wheels, among which 15, 16 inches refers to the size (diameter) of the wheel hub.
2. Hub width: The width of the hub is also commonly known as the J value. The width of the hub directly affects the choice of tires. For tires of the same size, with different J values, the aspect ratio and width of the selected tires are also different.
3. PCD and hole position: the professional name of PCD is pitch circle diameter, which refers to the diameter between the fixed bolts in the center of the hub. Generally, the large hole position of the hub is 5 bolts and 4 bolts, but the distance of the bolts is also different. Different, taking 5X114.3 as an example, it means that the PCD of this wheel hub is 114.3mm, and the hole position is 5 bolts. When choosing a wheel hub, PCD is one of the most important parameters. For safety and stability considerations, it is better to choose a wheel hub with the same PCD as the original car for upgrading.
4. Wheel hub offset: English is Offset, commonly known as ET value, the distance between the hub bolt fixing surface and the geometric center line (the center line of the hub cross section). In layman’s terms, it is whether the hub is retracted inward or convex after modification. Out. For ordinary cars, the ET value is positive, for a few vehicles and some jeeps, it is negative. For example, if the offset value of a car is 40, if it is replaced with an ET45 hub, it will visually be more retracted into the wheel arch than the original hub. The ET value not only affects the visual changes, it is also related to the steering characteristics of the vehicle and the wheel alignment angle. An offset value that is too large may cause abnormal tire wear, easy wear of the bearing, or even failure to install properly. .
In most cases, wheels of the same style of the same brand will provide different ET values to choose from. Comprehensive factors must be considered before modification. The safest case is to maintain the ET value of the modified wheel without modifying the brake system. The original ET value is the same.
5. Hub center hole: The center hole is the part used for the fixed connection with the vehicle, which is the position of the hub center and the concentric circle of the hub. The diameter size here affects whether we can install the hub to ensure that the geometric center of the rim can be consistent with the geometric center of the hub. . Although the hub shifter can change the hole pitch, this modification is risky, so try it carefully.
If you don’t know anything about changing wheels, you’d better find a professional tire shop with a brand to operate it. After all, safety is the top priority compared to that dazzling appearance.
