ISO/TC 31/SC 4 - Truck and bus tyres and rims

This document specifies laboratory test methods for verifying the capabilities of truck and bus tyres. Of the test methods presented, only some will be required, depending on the type of tyre to be tested. This document applies to all truck and bus tyres. The test methods presented in this document do not apply to the gradation of tyre performance or quality levels.

This document specifies the designations, contours and dimensions of drop-centre (one-piece) rims for use on trucks and buses. The rim dimensions are those rim contour dimensions necessary for mounting and fitment of the tyre to the rim. Tyre designations, dimensions and load ratings are given in ISO 4209‑1.

ISO 9112:2008 specifies two methods for measuring the rolling circumference and the number of revolutions per unit distance (kilometre) of new commercial vehicle tyres, under loaded conditions, for use on trucks and buses. The first method is a drum method consisting of loading a test tyre mounted on a free axle against a driven road wheel (or drum) of specified diameter. The second method involves a vehicle whose drive axle is equipped with the test tyres driven on a straight, paved road. The values thus obtained are not intended for use as levels of performance or quality. ISO 9112:2008 applies to all truck and bus tyres.

Of the test methods presented (strength test for the structure, endurance test), only some may be required depending on the type of tyre to be tested. The tests are carried out in a laboratory under controlled conditions. Applies to all truck and bus tyres.

ISO 4209-2:2012 specifies the designations, contours and dimensions of drop-centre (one-piece) rims for use on trucks and buses. The rim dimensions are those rim contour dimensions necessary for mounting and fitment of the tyre to the rim. Tyre designations, dimensions and load ratings are given in ISO 4209-1.

This part specifies the designation, dimensions, and load ratings of tyres primarily intended for trucks and buses. It applies to bias-belted, diagonal and radial tyres mounted on 5° tapered rims and on 15° tapered (drop-centre) rims. It is also applicable to different concepts and types of tyres and rims; in these cases, however, appropriate rim/section ratios, coefficients, and construction codes have been added to tables 2 and 3.

Specifies the designations, contours and dimensions of drop-centre (one-piece) rims. The rim dimensions are those rim contour dimensions necessary for mounting and fitment of the tyre to the rim. Tyre designations, dimensions and load ratings are given in ISO 4209-1.

Applies to all truck and bus pneumatic tyres. In measuring tyre rolling resistance, it is necessary to measure small forces in the presence of much larger forces. It is, therefore, essential that equipment and instrumentation of appropriate accuracy be used. Annex A gives test equipment tolerances, annexes B and C (informative) describe optional test conditions and measurement methods of moment of inertia.

Applies to all truck and bus tyres. Specifies methods for measuring rolling circumference and revolutions per unit distance (kilometre). The values thus obtained are not intended for use as levels of performance or quality.