# What is the bore diameter of a wheel?

## What is the bore diameter of a wheel?

The bore diameter is the internal size of the bore. This measurement is required in order for the wheel to fit the existing axle assembly properly. While looking at the side of the wheel, measure across the inside of the opening in the center of the wheel where the axle passes through.

## How do I know my wheel bore size?

Measuring The Wheel

1. Step 1: Set wheel face down on a flat surface. Be sure to protect the lip from scratches.
2. Step 2: Tare Caliper. Make sure caliper reads “0.00” when fully closed.
3. Step 3: Measure using “Inside diameter” tool. The top of your caliper is designed to measure the inside diameter of the wheel.

## Can I use a wheel with a larger center bore?

If the diameter of the hub collar is larger than the central bore, it will be impossible to fit the new wheels. On the other hand, if the center bore is larger than the diameter of the hub, the wheel can be fitted, but unwanted diameter differences will be problematic.

## How do you measure an alloy center bore?

The centre bore is the diameter of the hole in the centre of the nave plate. To measure this, measure from one side of the centre hole to the opposite side, as the diagram shows.

## Is wheel bore size important?

The centerbore of a wheel is the machined opening in the center of the wheel that centers the wheel properly on a vehicle. It is important for a wheel to be “Hub Centric” because it will reduce the chance of vibration.

## Is bore diameter or radius?

The bore measurement is a diameter, so you need to divide it by 2 to find the radius.

## Can the center bore be smaller?

You’ll have to measure the lip on the hub to see what mm spacer is needed to clear it. Most stock studs can only take 5mm spacers at most while still giving enough thread for enough rotations. Bolt on spacers isn’t going to work since they’re typically designed to keep the same bore on both sides.

## How do I know what size alloy wheels to buy?

Typically, the alloy wheel size conforms to the following format:

1. 20 x 8.5J.
2. 4 x 100.
3. 4 is the number of bolt holes, and 100 is the diameter of the PCD in mm.
4. When increasing your car’s wheel rim diameter by 1 inch: increase the tyre section width by 10mm and decrease the tyre aspect ratio by 10 points.

## Does hub bore size have to be exact?

Yes, you absolutely need to ensure any spacers mate with the wheel center bore and wheel hub precisely, either by being the correct diameter themselves or with hubcentric rings to make up the difference in size. If your hub bore is 57.1mm, your spacer center bore and outer bore need to also be 57.1mm too.