Measuring for or measuring a wheel spacer involves understanding specific dimensions to ensure proper fitment and desired wheel positioning.
To get started with measuring, all you need is a straight edge. And a ruler. This simple setup is key for determining the clearance you have and the appropriate spacer thickness needed.
Measuring For Wheel Spacers
Determining the correct thickness of a wheel spacer involves checking the available clearance between your wheel and the fender or other suspension components. This ensures the wheel doesn't rub after installation.
Here's how to measure for the necessary spacer thickness using a straight edge and ruler, as indicated in the reference:
- Position the Wheel: Install your wheel onto the hub but do not tighten the lug nuts fully yet.
- Place the Straight Edge: Hold a straight edge vertically against the outermost part of the wheel/tire tread.
- Measure the Gap: Use your ruler to measure the distance from the inner side of the straight edge to the fender lip or the closest suspension component. This measurement is the maximum thickness of the spacer you can install before potentially causing rubbing.
- Consider Clearance: Subtract a safety margin (typically 3-5mm) from this measurement to allow for suspension travel and tire flex. The result is the recommended maximum spacer thickness.
Example: If you measure a gap of 20mm between the straight edge and the fender lip, a 15mm or 18mm spacer might be appropriate, leaving a safety margin.
Measuring a Wheel Spacer Itself
If you already have a wheel spacer and need to know its specifications, you'll need to measure its key dimensions.
Key Dimensions to Measure
- Thickness: This is the most straightforward measurement. Use a ruler or caliper to measure the depth or thickness of the spacer. Common thicknesses range from 3mm up to 50mm or more.
- Bolt Pattern (PCD - Pitch Circle Diameter): This indicates the number of lug holes and the diameter of the circle they form.
- Measure the distance between the centers of two adjacent holes for a 4-lug or 6-lug pattern. This requires a specific calculation depending on the number of lugs.
- For a 5-lug pattern, measure the distance from the center of one hole across the center bore to the outside edge of one of the opposite holes, then subtract half the diameter of one hole. Alternatively, measure center-to-center between two non-adjacent holes and multiply by 1.051 (for 5-lug).
- Example: A common 5-lug pattern is 5x114.3mm, meaning 5 lugs on a 114.3mm diameter circle.
- Center Bore: This is the diameter of the large hole in the center of the spacer that fits over the vehicle's hub or the wheel's hub bore.
- Use calipers to measure the internal diameter of this center hole.
- Example: A common center bore size for many cars is 73.1mm or 66.1mm.
- Outer Diameter: The overall diameter of the spacer itself. While less critical for fitment than PCD and Center Bore, it's a defining dimension.
Tools for Measuring a Spacer
- Ruler or Measuring Tape: Useful for thickness and estimating larger dimensions.
- Calipers: Essential for precise measurements of thickness, bolt pattern (especially center-to-center distances), and center bore diameter.
- PCD Measurement Tool: Specialized tools exist to quickly and accurately determine the bolt pattern.
Understanding these measurements ensures you select or identify the correct spacer for your vehicle and wheels.
