Hub Centric Ring Size Calculator
Instantly determine the correct hub centric ring size needed to perfectly mate your aftermarket wheels to your vehicle’s hub, eliminating vibration and ensuring safety.
Calculate Your Ring Size
Visualization of the wheel bore, vehicle hub, and the required hub centric ring.
What is a Hub Centric Ring?
A hub centric ring is a small but critical device used when installing aftermarket wheels onto a vehicle. Its sole purpose is to fill the gap between the vehicle’s wheel hub and the center bore of the wheel. When a wheel’s center bore is larger than the vehicle’s hub, a gap exists. This hub centric ring slides into this gap, ensuring the wheel is perfectly centered on the hub. This perfect centering is crucial for preventing vibrations that can be felt in the steering wheel, especially at higher speeds. This is where a hub centric ring size calculator becomes an indispensable tool.
Anyone installing aftermarket wheels that are not specifically custom-made for their vehicle’s exact hub size should use hub centric rings. This includes car enthusiasts, mechanics, and everyday drivers looking to upgrade their vehicle’s appearance. A common misconception is that the lug nuts or bolts are sufficient to center the wheel. While lug nuts do secure the wheel to the car, they are not designed to bear the vehicle’s weight or ensure perfect alignment. Relying only on lug nuts can lead to wheel imbalance and persistent vibrations. Using a hub centric ring size calculator ensures you purchase the correct size for a vibration-free experience.
Hub Centric Ring Formula and Explanation
The calculation for determining the correct hub centric ring is straightforward but requires precise measurements. There are two key dimensions you need, and our hub centric ring size calculator handles this for you. The principle is to match the ring’s diameters to the components it connects.
- Ring Inner Diameter (ID): This must match the outer diameter of your vehicle’s hub bore.
- Ring Outer Diameter (OD): This must match the center bore diameter of your aftermarket wheel.
The formula is simply a statement of fitment: Ring Size = [Wheel Center Bore] to [Vehicle Hub Bore]. For example, if your wheel has a 73.1mm center bore and your car’s hub is 67.1mm, you need a 73.1mm to 67.1mm hub centric ring.
Variables used in the hub centric ring size calculator.
| Variable | Meaning | Unit | Typical Range |
|---|---|---|---|
| Vehicle Hub Bore | The outer diameter of the hub flange on the vehicle’s axle. | mm | 54.1 – 110+ |
| Wheel Center Bore | The diameter of the large central hole in the back of the wheel. | mm | 60.1 – 110+ |
| Ring Wall Thickness | The thickness of the ring material, calculated as (Wheel Bore – Hub Bore) / 2. | mm | 1 – 15 |
Practical Examples (Real-World Use Cases)
Example 1: European Car Upgrade
Imagine you own a 2018 Audi A4, which has a vehicle hub bore of 66.6mm. You purchase a set of aftermarket wheels that were previously on a BMW, which have a larger center bore of 72.6mm.
Inputs for the hub centric ring size calculator:
– Vehicle Hub: 66.6 mm
– Wheel Bore: 72.6 mm
Output: The calculator will specify that you need a 72.6mm to 66.6mm hub centric ring. Installing this ring will fill the gap, ensuring the wheel mounts perfectly centered and preventing any potential steering wheel shake on the highway.
Example 2: Japanese Car Customization
A person buys a 2020 Subaru WRX with a stock hub size of 56.1mm. They find a great deal on lightweight racing wheels, but these wheels have a center bore of 73.1mm to fit a wide range of cars.
Inputs for the hub centric ring size calculator:
– Vehicle Hub: 56.1 mm
– Wheel Bore: 73.1 mm
Output: The required ring size is 73.1mm to 56.1mm. Without these rings, there would be a significant gap, making it nearly impossible to center the wheel correctly, leading to major vibrations and unsafe driving conditions. The hub centric ring size calculator makes finding this specific size simple.
How to Use This Hub Centric Ring Size Calculator
- Measure the Vehicle Hub Bore: For the most accurate results, use a digital caliper to measure the outer diameter of your vehicle’s hub lip. If you don’t have calipers, you can often find this specification by searching online for your vehicle’s year, make, and model + “hub bore size”. Enter this value in the “Vehicle Hub Bore Diameter” field.
- Measure the Wheel Center Bore: Turn your aftermarket wheel over and use the digital caliper to measure the large hole in the center. Enter this number into the “Wheel Center Bore Diameter” field of the hub centric ring size calculator.
- Review the Results: The calculator will instantly provide you with the required hub centric ring size, formatted as Outer Diameter to Inner Diameter (e.g., “72.6mm to 66.6mm”). It also shows the individual inner and outer diameters and the wall thickness of the ring.
- Make Your Purchase: Use the precise dimensions from the calculator to purchase the correct set of hub centric rings.
Key Factors That Affect Hub Centric Ring Results
While a hub centric ring size calculator provides the dimensions, several factors influence the choice and performance of the rings.
- Material: Hub centric rings are typically made from either durable polycarbonate (plastic) or aluminum. Plastic rings are resistant to corrosion and are often less expensive, while aluminum rings offer greater strength and heat resistance, which can be beneficial for high-performance driving or track use.
- Measurement Accuracy: The most critical factor is accuracy. An error of even half a millimeter can result in a poor fit. Using digital calipers is highly recommended over a tape measure for obtaining precise values for the hub centric ring size calculator.
- Lug-Centric vs. Hub-Centric: Understand that factory wheels are almost always “hub-centric,” meaning they are centered by the hub. Most aftermarket wheels are “lug-centric,” designed with a large center bore to fit many vehicles, thus requiring hub centric rings to become hub-centric.
- Manufacturing Tolerances: Both vehicle hubs and wheel bores have slight manufacturing tolerances. A quality hub centric ring will be designed to accommodate these slight variations for a snug fit.
- Corrosion and Seizing: If using aluminum rings, especially in areas with harsh winters (road salt), applying a thin layer of anti-seize compound to the vehicle hub before installation can prevent the ring from getting stuck. Plastic rings do not have this issue.
- Proper Installation: The ring should slide onto the vehicle’s hub snugly by hand and fit securely into the wheel’s center bore. It should not be forced on, nor should it be loose or rattle.
Frequently Asked Questions (FAQ)
Yes, if your aftermarket wheel’s center bore is larger than your vehicle’s hub. They are essential for centering the wheel to prevent vibrations and ensure the load is properly distributed, which contributes to safety. Using a hub centric ring size calculator is the first step.
No. This is a common misconception. The hub centric ring’s only job is to center the wheel during installation. Once the lug nuts are torqued down correctly, the friction between the wheel and the hub mounting surface carries the vehicle’s weight.
Both have their merits. Plastic (polycarbonate) rings are rust-proof, affordable, and sufficient for most daily driving applications. Aluminum rings offer superior strength and heat dissipation, making them a better choice for heavy-duty, racing, or high-performance applications.
You will likely experience significant vibrations, especially between 50-70 mph (80-110 km/h). This vibration can cause premature wear on your tires, suspension components, and wheel bearings, and it creates an uncomfortable and potentially unsafe ride.
The most reliable method is to measure it with digital calipers. Alternatively, you can search online databases by your vehicle’s make, model, and year. Be sure to use a reliable source, as this measurement is critical for the hub centric ring size calculator.
This is unlikely if measured correctly. However, if it happens, re-measure carefully. Hub and wheel bores are made to standard sizes. You should always round to the nearest tenth of a millimeter. Do not guess; an incorrect size will not work.
Generally, yes. If they are in good condition (not cracked, warped, or heavily corroded), they can be reused. Always inspect them when changing wheels. Since they are relatively inexpensive, replacing them when buying new wheels is a good practice.
Yes, the principle of measuring the vehicle hub and the wheel bore is universal. This calculator works for any car, truck, or SUV, as long as you provide it with accurate measurements in millimeters.