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.

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.

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.

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

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.

57. Following the suggestion of the WP.29, the secretariat introduced GRRF-78-04 containing a list of definitions in the Regulations under the responsibility of GRRF. The Chair of GRRF recalled GRRF‑76‑03 and noted that no follow-up action was defined. The secretariat announced that it was looking for a central and suitable location on the website to collect this useful information.

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.