The center bore measurement of a wheel is the size of the hole on the backside of the wheel, usually measured in millimeters (mm). In some countries, this is also referred to as spigot size. When shopping for wheels or hub centric rings, it’s important to know the center bore of the wheels. We’ll break it down and explain how to obtain the center bore measurement of your wheels.
The Easy Way
Most wheel vendors and manufacturers list wheel specifications in an easy to find place. Some wheel boxes list the center bore specification, and most wheel manufacturer and vendor websites list it as well. The easiest way to find the center bore of your wheels is to check here.
Measuring The Wheel
If buying wheels second hand, or in the event the center bore measurement isn’t available from your wheel vendor or wheel manufacturer, the hole can easily be measured using a caliper or even a ruler.
- Digital Caliper
- Wheel to measure
Step 1: Set wheel face down on a flat surface. Be sure to protect the lip from scratches.
Step 2: Tare Caliper. Make sure caliper reads “0.00” when fully closed.
Step 3: Measure using “Inside diameter” tool. The top of your caliper is designed to measure the inside diameter of the wheel. Carefully spread the probes outward across the center of the hole to get an accurate measurement.
If using this measurement for ordering hub rings, note that the inside diameter of your wheel’s center bore will be the outside diameter of your hub ring measurement.