Proposal to amend paragraph 2.2. to clarify the definition of “Supplier of the tread used for retreading process”; insert new subparagraph (a) in paragraph 6.4. establishing requirements for class C1 tyres; renumber former subparagraphs (a) and (b) as (b) and ©; replace “Appendix 1” with “Schedule 1” in paragraph 8.; amend paragraph 12.1. concerning type approvals as from 1 September 2030; amend paragraph 12.3. regarding acceptance of existing type approvals of class C3 tyres; and amend Annex 1 regarding communication of type approval for retreaded tyres.

Proposal to amend UN Regulation No. 172 based on GRBP/2026/10 as amended by GRBP-83-15-Rev.1. Amendments include revised definition of supplier of tread in paragraph 2.2.; modification of paragraph 6.2. to require tyres to meet conditions in paragraph 6.2.1. or 6.2.2.; insertion of new paragraphs 6.2.2., 6.2.2.1., 6.2.2.2., and 6.2.2.3. establishing calculation methods for deformation potential and number of traction elements based on tyre class and nominal rim diameter; insertion of new paragraph 6.4.(a) for class C₁ tyres; renumbering of former paragraphs 6.

Proposal to:

1. Clarify that the “supplier of the tread used for the retreading process” is responsible for conformity of production of the
   supplied tread,
2. Align the classification “traction tyre” with UN R117
3. Provide transitional provisions to manage the switch from the requirements given in paragraph 6.2.1. to the ones given in the paragraph 6.2.2.,
4. Correct the omission of provisions for “professional off-road tyre” and their alignment with UN R30,/li>
5. Correct a reference to “Appendix 1” of the 1958 Agreement to “Schedule 1”, and
6. Manage the transition to the new standard reference test tyres (SRTTs)
   19.5 and 22.5 siped

Proposal to reinsert requirements for the classification of tyres of class C1 that were erroneously omitted in the amendments to para. 6.4. introduced via Supplement 1 and to align the wording with UN R30, to correct a reference to “Appendix 1” that should read “Schedule 1”, and to delete the field for “Extension No.” in the Communication form since the extension is already integral to the Approval Number.

Proposal to:

1. Add new reference tyres C3 SRTTs 19.5 and 22.5 siped and related transitional provisions
2. Simplify the wording of the requirements for
   professional off-road tyres
3. Make editorial corrections where needed throughout the text.

Proposal to:

1. Add new reference tyres C3 SRTTs 19.5 and 22.5 siped and related transitional provisions
2. Simplify the wording of the requirements for
   professional off-road tyres
3. Make editorial corrections where needed throughout the text.

Consolidated version including the amendments proposed with document ECE/TRANS/WP.29/GRBP/2024/11 amended by GRBP-79-28-Rev.1.

This consolidated document amends and supersedes GRBP/2024/11.

Proposal from the ad hoc working group on retreaded tyres to move provisions for snow grip performance of retreaded tyres and their classification as traction tyres from UN R108 and R109 into a new UN Regulation on type approval of retreaded tyres of classes C1, C2 and C3 with respect to their snow grip performance and/or classification as traction tyre.