Measuring Bolt Circle

The bolt pattern or bolt circle of a wheel is the diameter of the circle drawn through the centers of the bolt holes. Bolt pattern is expressed in the form of number of lugs by diameter such as 5x4.25" or 4x100mm. The diagrams show the proper way to measure the bolt circle diameter of four, five, six and eight lug patterns.

Measuring Backspacing

Backspacing is the distance from the back of the bolt flange where it contacts the hub mounting pad to the inside lip of the wheel. To measure backspacing, place a straight edge against the inside lip of the rim with the outside of the wheel facing down and measure from the bottom of the straight edge to the mounting flange. Increasing the backspacing of a wheel will move the wheel inside the fender more and decreasing it will push it out and give it the dished look.

Measuring Offset

Offset describes the dimension from the centerline of the rim to the mounting flange of the center section. A positive offset will put the mounting flange on the outside of the centerline and push the wheel into the fender more. A negative will put the mounting flange of the inside of the centerline and move the wheel out of the fender. Positive offset rims are most commonly found on front wheel drive cars.

Wheel Width

The width of the rim is specified from the edge of one bead seat to the other according to industry standards.

Inner and Outer Fender Clearance

This is the measurement from the inside rim flange to inner fender and outer rim flange to outer fender. These measurements need to take into consideration the extra bulge width of the tire when mounted. The rear should be measured with the suspension fully extended and collapsed. The front should be measured with the wheels turned from lock to lock with the suspension both fully extended and fully compressed. Adequate clearance is necessary to ensure safe running of the wheels and tires or the tire may rub against other components and fail.

Fitment Return Policy

No returns can be made due to fitment problems on custom fit wheel sets. Please be very careful to ensure proper measurement before ordering. We recommend having a professional take the proper steps to measure the wheels if you are at all unsure of your ability to properly do so. For stock replacement applications we can make the rims to original factory specifications, allowing the original tires to be reused and original fit to be obtained. If you have any questions about fitment issues, send us an email or give us a call.