【Owner's home car knowledge】There are many kinds of hubs according to diameter, and there are many kinds according to width. Then, different diameters, different widths, and different materials can be divided into many models. Some car owners think that the original tires are not high-end enough, and want to upgrade, often widening, reducing the aspect ratio, increasing the diameter, and changing the material. At this time, if the wheel hub must be changed, it is called a modified wheel hub.
1. What are the types of wheels?
According to the surface treatment process of the wheel hub, different methods will be adopted, which can be roughly divided into two types: baking paint and electroplating.
1. The price of painted wheels is moderate and durable.
The appearance of the wheels of ordinary models is less considered. Good heat dissipation is a basic requirement. The process is basically treated with baking paint, that is, spraying first and then electric baking. The cost is relatively economical and the color is beautiful and lasts for a long time. Even if the vehicle is scrapped , the color of the wheel remains unchanged.
The surface treatment process of many Volkswagen model wheels is baking paint, and some fashionable, dynamic and colorful wheels use baking paint technology. These wheels are moderately priced and complete in specifications.
2. The price difference of electroplated wheels is large.
Electroplated wheels are divided into electroplating silver, water electroplating and pure electroplating. Although the electroplated silver and water electroplated wheels are bright and vivid in color, they last for a short time, so the price is relatively cheap, and they are liked by many young people who pursue freshness.
The pure electroplated wheel hub keeps the color for a long time, which can be said to be of high quality and high price. Some mid-to-high-end cars will be equipped with pure electroplated wheels as standard.
Wheels can be divided into two categories according to their materials: steel wheels and alloy wheels.
3. The main advantage of steel wheels is that the manufacturing process is simple, the cost is relatively low, and the ability to resist metal fatigue is very strong, which is what we commonly call cheap and strong. However, the disadvantages of steel wheels are also relatively prominent, that is, the appearance is not beautiful enough, the weight is large, the inertial resistance is large, the heat dissipation is relatively poor, and it is very easy to rust.
4. Alloy wheels have light weight, small inertial resistance, high manufacturing precision, small deformation and small inertial resistance during high-speed rotation, which is conducive to improving the straight-line driving performance of the car and reducing tire rolling resistance, thereby reducing fuel consumption.
The thermal conductivity of the alloy material is about three times that of steel, and the heat dissipation is good. It can play a certain role in the heat attenuation of the vehicle's braking system, tires and braking system.
At present, the alloy wheels of original cars on the market are mainly made of aluminum alloy. Of course, many modified wheels will choose chrome, titanium and other elements as basic materials in order to meet certain special requirements and improve vision.
However, compared with steel wheels, the price of alloy wheels is much more expensive, so in many low-end original cars, steel wheels will appear on low-end models, while alloy wheels are high-end models. Standard on the model.
Second, the basic structure of the car wheel hub:
1. Rim: It is assembled with the tire to support the wheel part of the tire.
2. Spoke: It is installed and connected with the hub of the axle to support the wheel part of the rim.
3. Offset distance: the distance from the center surface of the rim to the mounting surface of the spokes. There are positive offset, zero offset and negative offset.
4. Rim: The part of the rim that maintains and supports the direction of the tire.
5. Bead seat: It is in contact with the tire ring and supports the part of the rim that maintains the radial direction of the tire.
6. Groove bottom: In order to facilitate the assembly and disassembly of tires, a pit with a certain depth and width is left on the rim.
7. Valve hole: the hole for installing the tire valve.
3. How to choose wheels for the car?
Generally speaking, don't blindly increase the size of the hub. Some people increase the size of the wheels in order to improve the performance of the car. When the outer diameter of the tires remains the same, the larger wheels are bound to match the wide and flat tires. The lateral swing of the car is reduced, the stability is improved, and it is like a superficial light when cornering skimming. But the flatter the tire, the thinner its thickness, the worse the shock absorption performance, and the greater the sacrifice in comfort.
In addition, if there are roadblocks such as stones, the tires are easily damaged. Therefore, the cost of blindly increasing the hub cannot be ignored. Generally speaking, it is most appropriate to increase one or two sizes according to the size of the original wheel hub.
The complex and dense wheel hub is indeed beautiful and high-grade, but it is easy to be rejected or overcharged when washing the car because it is too troublesome to clean. The simple wheels are dynamic and neat.
Aluminum alloy wheels, compared with the old cast iron wheels, have greatly improved the degree of deformation resistance, greatly reduced weight, less vehicle power loss, fast running, fuel-efficient and good heat dissipation.
A wheel includes many parameters, and each parameter will affect the use of the vehicle, so before modifying and maintaining the wheel, you must first confirm these parameters.
1. Hub size:In fact, it is the diameter of the wheel hub. We often hear people talking about 15-inch wheels and 16-inch wheels. Among them, 15 and 16 inches refer to the size (diameter) of the wheel hub.
Generally, on a car, if the size of the wheel hub is large and the flat ratio of the tire is high, it can have a good tension effect visually, and it will also increase the stability of the vehicle's handling, but the fuel consumption will increase accordingly. Such additional questions.
2. Hub width:The width of the wheel hub is also commonly known as the J value. The width of the wheel hub directly affects the selection of the tire. For tires of the same size, the J value is different, and the aspect ratio and width of the selected tire 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 holes in the hub are 5 bolts and 4 bolts, but the distance between the bolts is also different, so we can often hear To 4X103, 5X114.3, 5X112, taking 5X114.3 as an example, it means that the PCD of this wheel hub is 114.3mm, and there are 5 bolts in the hole.
When choosing a hub, PCD is one of the most important parameters. For safety and stability considerations, it is best to choose a hub with the same PCD as the original car for upgrading.
4. Hub offset:English is Offset, commonly known as ET value, the distance between the hub bolt fixing surface and the geometric centerline (hub cross-section 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 entire rim, popular point That is to say, whether the hub is indented or protruded outward after modification.
ET is positive for normal cars and negative for a few vehicles and some jeeps. For example, if the offset value of a car is 40, if it is replaced with ET45 wheels, it will be more retracted into the wheel arch visually than the original wheels.
The ET value not only affects the visual changes, but also has a relationship with the vehicle's steering characteristics and wheel alignment angle. If the offset value is too large, it may cause abnormal wear of the tires, easy wear of the bearings, or even failure to install normally. .
In most cases, the wheels of the same brand and style will provide different ET values to choose from. Comprehensive factors should be considered before modification. The safest situation is to keep the ET value of the modified wheel with the premise of not modifying the brake system. The factory ET value is the same.
5. Hub center hole:The center hole is the part used for fixed connection with the vehicle, which is the position of the center of the hub and the concentric circle of the hub. The diameter size here affects whether we can ensure that the geometric center of the rim coincides with the geometric center of the hub when installing the hub. Although the wheel hub shifter can change the hole pitch, there are risks in this modification, so try it carefully.
