17. The experts from France, the Netherlands and BIPAVER proposed to align the provisions for retreaded tyres with the previously adopted proposals for UN Regulations Nos. 30 and 117 and to cover all tread materials (ECE/TRANS/WP.29/GRBP/2021/15). The expert from ETRTO commented on the proposal and suggested further modifications (GRBP-74-29-Rev.1 and GRBP-74-35-Rev.1). GRBP adopted the proposal, subject to the amendments in Annex III of the session report, and requested the secretariat to submit it for consideration and vote at the March 2022 sessions of WP.29 and AC.1 as draft Supplement 6 to UN Regulation No. 108.

18. The experts from France, the Netherlands and BIPAVER proposed to align the provisions for retreaded tyres with the previously adopted proposals for UN Regulations Nos. 54 and 117 and to cover all tread materials (ECE/TRANS/WP.29/GRBP/2021/16). The expert from ETRTO commented on the proposal and suggested further modifications (GRBP-74-29-Rev.1 and GRBP-74-30-Rev.2). GRBP adopted the proposal with the amendments in Annex IV and requested the secretariat to submit it for consideration and vote at the March 2022 sessions of WP.29 and AC.1 as draft Supplement 11 to UN Regulation No. 109.

17. The experts from France, the Netherlands and BIPAVER proposed to align the provisions for retreaded tyres with the previously adopted proposals for UN Regulations Nos. 30 and 117 and to cover all tread materials (ECE/TRANS/WP.29/GRBP/2021/15). The expert from ETRTO commented on the proposal and suggested further modifications (GRBP-74-29-Rev.1 and GRBP-74-35-Rev.1). GRBP adopted the proposal, subject to the amendments in Annex III of the session report, and requested the secretariat to submit it for consideration and vote at the March 2022 sessions of WP.29 and AC.1 as draft Supplement 6 to UN Regulation No. 108.

15. The experts from France and EC introduced an updated proposal for the new definition of “radial tyre” (ECE/TRANS/WP.29/GRBP/2021/9). The same definition was also proposed for UN Regulations Nos. 54, 75, 106, 108 and 109 ECE/TRANS/WP.29/GRBP/2021/10. The experts from Canada and the United States of America raised a number of questions on the proposal (GRBP-74-07) and pointed out that they had started consultations with the authors. GRBP invited the stakeholders, in liaison with ETRTO, to continue discussions and agreed to come back to the proposal at the next session.

12. GRBP noted that the experts of BIPAVER had withdrawn document ECE/TRANS/WP.29/GRBP/2021/2.

19. On behalf of the Group Of Interested Experts on snow tyre provisions (GOIE), the expert from Germany reported on their progress (GRBP-71-20). In particular, he proposed establishing a new task force on studded tyres with the objective to draft a new UN Regulation on the approval of studded tyres regarding their snow performance. GRBP endorsed this proposal and noted that the duties of the Chair and Secretary of the task force would be performed by the experts from Finland and ETRTO, respectively.

20. With additional explanations of GOIE (GRBP-71-26), GRBP resumed discussion on the new class of special use tyres intended for use under severe snow conditions (ECE/TRANS/WP.29/GRBP/2019/14). GRBP noted that the proposed new class would provide for better road safety characteristics under severe snow conditions, but with a small increase in the rolling noise. The experts from Germany, Netherlands and Russian Federation supported the proposal. The expert from EC was not in position to agree to the proposal, due to the envisaged higher noise limits which would require modifications of European Union legislation. GRBP decided to revert to this issue at the next session.

11. GRBP agreed to postpone consideration of ECE/TRANS/WP.29/GRBP/2019/6 to the next session.

15. GRBP reverted to the postponed proposal on retreaded tyres to be tested and marked with the three-mountain-peak snow-flake (3PMSF) symbol, which was submitted by the experts of BIPAVER. GRBP adopted the document and requested the secretariat to submit it to WP.29 and AC.1 for consideration and vote at their June 2020 sessions as Supplement 5 to UN Regulation No. 108.

34. The expert from BIPAVER introduced ECE/TRANS/WP.29/GRRF/2018/8 with similar provisions as those in ECE/TRANS/WP.29/GRRF/2018/9 and proposed as amendments to UN Regulation No. 108. GRRF adopted the proposal as amended by Annex IV (of this report) and requested the secretariat to submit it as draft Supplement 4 (corrected by GAR from Supplement 9 in the published session report.) to UN Regulation No. 108 for consideration and vote by WP.29 and AC.1 at their June 2018 sessions.

44. The expert from the Russian Federation introduced ECE/TRANS/WP.29/GRRF/2017/25 proposing a Corrigendum in Russian only of Regulation No. 108. GRRF adopted the proposal and requested the secretariat to submit it as draft Corrigendum to Regulation No. 108 to WP.29 and AC.1 for consideration and vote at their March 2018 session.

48. The expert from Germany introduced GRRF-83-05 looking for guidance on the possibility to develop snow tyre provisions for all tyres and vehicles categories as it was already existing for snow tyres of category C1, C2 and C3 for vehicles categories M and N by amending all relevant Regulations or by amending the scope of Regulation No. 117. The expert from Japan and the Russian Federation volunteered to contribute to the work item proposed by Germany. GRRF requested to add an agenda item dedicated to snow tyres on the agenda.

47. The expert from ETRTO presented GRRF-82-21 collecting the definitions in UN Regulations on tyres. He added that doing this review, they noted some possible harmonization of definitions across the Regulations. They invited the delegates to review the document and to indicate whether GRRF would support amending the Regulations in order to harmonize the definitions when relevant or develop a Resolution containing definitions. GRRF agreed to keep this document on the agenda of the next session.

47. The Chair of GRRF, recalling the purpose of GRRF-82-21 collecting the definitions in UN Regulations on tyres invited the expert from ETRTO to report on derived activities. The expert from ETRTO reported that he didn’t receive any feedback on this document. GRRF agreed to keep this document on the agenda of the next session.