How to decide the thickness/width of the wheel spacer or wheel adapter?

There are various thickness (or width) options of wheel spacers wheel adapters in the market under various types or designs. The most seen are like 3mm, 5mm, 7mm, 8mm, 10mm, 12mm, 15mm, 18mm, 20mm, 25mm (or 1”), 30mm (or 1.25”), 35mm, 38mm (or 1.5”), 40mm, 45mm (or 1.75”), 50mm (or 2”), 60mm, 2.5”, 3” and etc. There are also custom made like 4mm, 11mm, 16mm, 23mm, 55mm, 75mm, 80mm, 90mm, 4” and even to 110mm.

Undoubtedly, the desired performance cannot be achieved if any wheel spacers (or adapters) with improper thickness/width are adopted. Moreover, the improper thickness/width may bring issues during installation or driving. Then how to decide the proper thickness (or width) wheel spacers (or wheel adapters) for the specific vehicles?

Some effective and efficient methods are presented by some professionals. For example, the way by measuring the smallest gap between the outer straight edge of the tire and inner point of the fender, the way by flat washer and etc. These methods can be checked from the internet for reference.

On the meanwhile, for a specific vehicle even with chassis lifted and not likely with the limit of the fenders, close attention shall be paid to some other important factors as below:

1.   The hub height (refer to #pic 1). The center bore depth of the wheel spacers (or wheel adapters) must not be smaller than the car hub height to make sure they are seated fully on the car hub area without gap.

In some cases, when there are attached accessories like free hubs, the length of the free hubs has also been considered to make sure the wheel spacers or the wheel adapters can be installed without problem.

2.   The wheel bevel angle (refer to #pic 2). The wheel bevel angle must not be smaller than the wheel spacers’ bevel angle to make sure the wheels can be seated fully on the wheel spacers.

3.   The stud extrusion (refer to #pic 3). The extrusion shall not be more than the thickness (or width) of the wheel spacer/adapter plus the depth of the wheel’s cavities (refer to #pic 4). Otherwise, the wheel spacer/adapter cannot be seated on the vehicle hub area fully unless the studs are trimmed for shorter.

To avoid fit issues, before the order confirmation the serious makers and sellers may check seriously with the buyers for desired thickness/width and these important factors stated, or the limits of compatibility will be presented. Suggestions and solutions will be presented by them in case there would be problems to the desired thickness/width.