Measuring wheel backspace is a crucial step for ensuring proper fitment and clearance when selecting or replacing wheels on a vehicle. Backspace is defined as the distance from the hub mounting surface of the wheel to the outside edge of the wheel's inner flange.
Here's a straightforward guide on how to accurately measure wheel backspace:
Steps to Measure Wheel Backspace
To measure backspace correctly, you will need a straightedge (like a ruler or a piece of metal) and a measuring tape or ruler. The process involves measuring the depth from the wheel's mounting surface to its rear edge.
- Orient the Wheel: Place the wheel face down on a flat surface. This positions the inner side of the wheel upwards, making the mounting surface and inner lip accessible for measurement. As shown in demonstrations by Weld Racing, orienting the wheel face down is the standard first step.
- Position the Straightedge: Take your straightedge and lay it across the lip of the wheel. Ensure the straightedge spans the entire diameter of the wheel's back edge, resting firmly on the inner lip at two points directly opposite each other. The reference emphasizes placing the straightedge "across the lip."
- Measure the Distance: Measure the distance from the underside of the straightedge down to the hub mounting surface. The hub mounting surface is the flat area in the center of the wheel that makes contact with the vehicle's hub or brake rotor. This measured distance is the wheel's backspace.
Why is Backspace Important?
Understanding and measuring backspace is vital for several reasons:
- Fitment: It determines how far the wheel sits inward or outward relative to the vehicle's body and suspension components.
- Clearance: Proper backspace ensures the wheel and tire clear brake calipers, suspension arms, fenders, and frame.
- Handling: Changes in backspace can affect scrub radius, influencing steering feel and stability.
- Appearance: Backspace, along with wheel width, dictates the wheel's overall position and stance on the vehicle.
Tools Required
Measuring backspace requires minimal tools:
- A straightedge long enough to span the diameter of the wheel.
- A measuring tape or ruler, preferably with clear markings for accuracy.
By following these steps, you can accurately determine the backspace of your wheel, which is essential information for selecting compatible wheels for your vehicle.
