Proposal to align the definition of the temperature correction coefficient “K” in UN Regulation No. 117: 02 series of amendments with ISO 28580. The issue is linked to tire categories: ISO refers only to load index while UN R117: 02 series refers to class C1, C2 and C3 tires.
26. The Chair recalled the purpose of ECE/TRANS/WP.29/2012/54 harmonizing the definitions of “snow tyres” and “snow tyres for use in severe snow conditions” in UN Regulations Nos. 30, 54 and 117, for further consideration by GRB. The Chair of GRB presented GRRF-73-05, a proposal generated by GRB during its session in September 2012 which slightly modifies the GRRF proposal. GRB preferred to remove the marking M+S from UN Regulation No. 117. Only “snow tyres for severe condition” with the “Alpine Marking” are entitled to the bonus on limit values set in the Regulation (e.g. for “rolling noise”). GRRF endorsed the proposal by GRB as reproduced in GRRF-73-05-Rev.1 and agreed to submit it to WP.29 and AC.1 for consideration at their November 2012 sessions together with ECE/TRANS/WP.29/2012/54 as Supplement 02 to the 02 series of amendments to UN Regulation No. 117 (see WP.29-158-09).
27. The expert from ETRTO introduced ECE/TRANS/WP.29/GRRF/2012/17 amending UN Regulation No. 117, introducing the possibility to use a test track according to the new ISO standard 10844:2011. The expert from ETRTO preferred to insert transitional provisions into the proposed amendments (GRRF-73-26). GRRF endorsed the amendments proposed by GRB (GRRF-73-17) and confirmed there was no conflict with on-going amendments under consideration at GRRF.
28. The expert from ETRTO introduced ECE/TRANS/WP.29/GRRF/2012/18 correcting the provisions of the temperature compensation in Regulation No. 117. GRRF noted that this proposal had been simultaneously transmitted to GRB who had made recommendations for submission to WP.29 and AC.1 for consideration at their March 2013 sessions as Supplement 03 to the 02 series of amendments to UN Regulation No. 117.
29. The expert from ETRTO introduced ECE/TRANS/WP.29/GRRF/2012/19 amending the testing procedure for snow tyres of the category C3. GRRF noted some comments. GRRF agreed to consider a revised proposal at its next session
30. The expert of France presented a joint proposal of France / EC (GRRF-73-08) on wet grip testing provisions for Tyres of category C2 and C3. The expert from ETRTO introduced GRRF-73-18 and GRRF-73-21 in response to GRRF-73-08 with a proposal for limit values as well as transitional provisions. GRRF agreed to resume discussion on these issues on the basis of revised proposals tabled by ETRTO at its next session.