Tire Dimensions


 

Free Radius

The distance from the wheel axle centerline to the outer tread surface of the unloaded, properly inflated tire.

 

Static Loaded Radius

The distance from the wheel axle center line to the tread contact surface. Measured after the tire has been mounted on its measuring rim, inflated to the test pressure and placed under a prescribed load.

 

Overall Diameter

The linear distance between the tire’s tread surfaces measured at the widest point. This measurement is taken with the tire mounted on the measuring rim and no load applied.

Overall Width

The exterior measurement of a tire’s width from the inner to the outer sidewall (including protective ribs and decorations) when properly mounted and inflated.

 

Tread Width

The distance from the outer edge to the inner edge of the tread.

 

Tread Radius

The design curvature of the tread profile.

 

Section Height

The measurement of the vertical distance between the tire’s bead seat and outer tread surface when properly mounted and inflated, but with no load placed on the tire.

 

Section Width

The measurement of a tire’s width from sidewall to sidewall (excluding protective ribs or decorations) when properly mounted and inflated, but with no load placed upon the tire.

 

Rim Width

The linear distance between the outer and inner rim flanges on which the tire bead sits.

 

Nominal Rim Diameter

The linear distance between bead seats measured at the widest point. This measurement may be in inches or millimeters.

 

Groove Depth

The amount of manufactured tread measured at a predetermined location.