Proposal from the Worn Tyres working group to improve precision of the test procedures for measuring the wet adhesion of tyres in a worn state by using a moulded SRTT16 reference tyre (instead of a buffed tyre), to introduce new transitional provisions related to this change, to extend corrections already made to thee 02 series to the 03 series and make additional editorial corrections, and to define the range for tyre inflation vis-à-vis rim size to reduce uncertainties in measuring tread depth.
21. The expert of IWG WGWT proposed to add the missing references for the molded standard reference test tyre (SRTT16) in the 03 and 04 series of amendments to UN Regulation No. 117 (ECE/TRANS/WP.29/GRBP/2023/2 and ECE/TRANS/WP.29/GRBP/2023/3). GRBP endorsed these references and noted that they had been already included in ECE/TRANS/WP.29/2023/5 and ECE/TRANS/WP.29/2023/8 which would be considered by WP.29 and AC.1 at their forthcoming session in March 2023.
20. The expert of IWG WGWT presented their proposals for the moulded standard reference test tyre and wet grip of C2, C3, and some clusters of C1 tyres in a worn state (ECE/TRANS/WP.29/GRBP/2022/22, ECE/TRANS/WP.29/GRBP/2022/23, GRBP-76-02 and GRBP-76-05). The expert from ETRTO introduced additional amendments (GRBP-76-24-Rev.1, GRBP-76-33-Rev.1 and GRBP-76-34).
21. GRBP adopted ECE/TRANS/WP.29/GRBP/2022/22, as amended by GRBP-76-05 and GRBP-76-34, subject to the removal of the square brackets, and requested the secretariat to submit it for consideration and vote at the March 2023 sessions of WP.29 and AC.1 as draft Supplement 1 to the 03 series of amendments to UN Regulation No. 117.
22. GRBP adopted ECE/TRANS/WP.29/GRBP/2022/23, as amended by GRBP-76-02, GRBP-76-33-Rev.1, and GRBP-76-24-Rev.1, and requested the secretariat to submit it for consideration and vote at the March 2023 sessions of WP.29 and AC.1 as part of the draft new 04 series of amendments to UN Regulation No. 117.
| WT-44-05/Rev.1 | |
| GRBP-76-05 | |
| GRBP-76-34 | |
| GRBP/2023/2 | |
| WP.29/2023/6 |