Reference prepared by the WP.29 secretariat

Proposal to require wheel attachments with three or more fixing components (nuts or studs) in the scope of the Regulation, to restrict the difference in pitch circle diameter (PCD) of a wheel type comprised of more than two versions, to carry out additional rotating bending tests on each version with a PCD difference to a tested version of more than 6.5 mm, and to establish specifications for comparison of replica wheels with the minimum level of the vehicle manufacturer´s replacement wheels.

Proposal to require wheel attachments with three or more fixing components (nuts or studs) in the scope of the Regulation, to restrict the difference in pitch circle diameter (PCD) of a wheel type comprised of more than two versions, to carry out additional rotating bending tests on each version with a PCD difference to a tested version of more than 6.5 mm, and to establish specifications for comparison of replica wheels with the minimum level of the vehicle manufacturer´s replacement wheels.

Proposal to align the acceptance criterion listed in the table in Annex 8, paragraph 3, with the negative rating criterion listed in paragraph 5 (c): total loss of inflation pressure within one minute. This change clarifies that only a complete decrease in the pressure in the tyre due to its depressurization is a negative evaluation criterion when conducting an impact test.

Proposal to require wheel attachments with three or more fixing components (nuts or studs) in the scope of the Regulation, to restrict the difference in pitch circle diameter (PCD) of a wheel type comprised of more than two versions, to carry out additional rotating bending tests on each version with a PCD difference to a tested version of more than 6.5 mm, and to establish specifications for comparison of replica wheels with the minimum level of the vehicle manufacturer´s replacement wheels.

Proposals:

• Para. 2.2.3.: Information related to construction materials is clarified.
• Para. 2.2.4.: Deleted, since its content is covered by paragraph 2.2.8. in the proposed wording.
• Para. 2.2.8.: The notion of the wheel geometric shape is clarified.
• Para. 2.9.: The notion of defects caused by the production process is clarified. Only in the Russian language it is clarified that the crack propagation is actually a length and a depth of the crack. The proposed text makes it possible to distinguish between a crack that occurred during testing and a scratch, which may be an acceptable manufacturing defect.
• Para. 3.1.2.13.: The technical description of the wheel is supplemented with information describing the product quality control in the production process.
• Para. 5.1.6. and Annex 3: The application of optional marking is aimed at providing the consumers with information on the quality control of the manufactured wheel, as well as facilitating the selection of wheels with the required characteristics by consumers in case of providing with incomplete information on suitable vehicle types in accordance with paragraph 1.2. of Annex 10.
• Annex 4, para. (а): The language of the provision is clarified.
• Annex 4, paras. (b) and (d): Deleted, since the existing experience of testing confirms that the mechanical properties of the raw materials are not comparable with the mechanical properties of finished products (wheels). In this regard, there is no need to test the raw materials.
• Annex 4, para. (с): The list of critical zones on wheels where to take the material to check its characteristics is clarified. These critical zones shall be specified by the manufacturer in the application documentation, and they can also be specified by the technical service. A description of the characteristics of the material taken from paragraph (b) is provided, since this paragraph is deleted. Only in the Russian language the terms concerning the measured values have been changed.
• Annex 4, para. (e): It is specified that the analysis of metallurgical defects is carried out in the most loaded spots of the wheels. These spots shall be specified by the manufacturer in the application documentation, and they can also be specified by the technical service. The analysis shall be carried out in comparison with the permissible defects specified by the manufacturer.
• Annex 6: A recommendation is added to identify cracks occurred as a result of the test by using penetrating paints.
• Annexes 7 and 8: The pressure drop in the tyre as a consequence of testing the wheel assembly with the tyre may not be due to damage to the wheel, but to damage to the tyre. To eliminate uncertainty in the interpretation of the test results, it is necessary to determine the cause of the tyre pressure drop. If the pressure drop in the tyre was caused by its damage, then it is necessary to carry out the tests again, using a new tyre.

Proposal for a reference document concerning a general approach for how to handle measurement uncertainties under UN Regulations within the purview of GRBP.

Proposal to clarify the text:

• Term “construction materials”
• interpretation of paras. 2.2.4. and 2.2.8.
• supplement technical description of the wheel with information describing production quality control
• option for additional consumer-oriented marking
• clarify Annex 4 and exclude aluminum-alloy and magnesium-alloy wheels under test (b)
• clarify Annex 6 with regard to possible defects caused by the production process and not affecting the appearance of cracks during testing
• recommend under Annex 6 to identify cracks occurred as a result of the test by using penetrating paints
• clarify Annexes 7 and 8 with regard to air leakage.

This document supersedes the proposal in ECE/TRANS/WP.29/GRBP/2024/16