17. Referring to the report of the Working Party on Brakes and Running Gear (GRRF) (see ECE/TRANS/WP.29/GRRF/72, paras. 25 and 32-34), GRB considered ECE/TRANS/WP.29/2012/54 and ECE/TRANS/WP.29/2011/55, proposing to add specific performance requirements for C2 snow tyres and amending the definition of the measuring rim for C1, C2 and C3 tyres. GRB endorsed ECE/TRANS/WP.29/2012/55 without amendment, scheduled to be considered by WP.29 and AC.1 at their November 2012 sessions. Concerning ECE/TRANS/WP.29/2012/54, GRB considered GRB-56-15 tabled by the expert from Germany, proposing to introduce the inscription “M+S” or “M.S” or “M&S” only in combination with the “Alpine” symbol on a mandatory basis, if the tyre be classified as a “snow tyre for use in severe snow conditions”. Accordingly, GRB endorsed ECE/TRANS/WP.29/2012/54, as amended by Annex III to this report and agreed to submit it to WP.29 and AC.1, for consideration at their November 2012 sessions as draft Supplement 2 to the 02 series of amendments, subject to a final review by GRRF at its September 2012 session.
18. The expert from ETRTO introduced ECE/TRANS/WP.29/GRB/2012/10 aligning the text of Annex 6 of the UN Regulation to ISO Standard 28580. GRB adopted the proposal not amended and agreed to submit it to WP.29 and AC.1, for consideration at their March 2013 session as draft Supplement 3 to the 02 series of amendments to UN Regulation No. 117, also subject to a final review by GRRF at its September 2012 session (see ECE/TRANS/WP.29/GRRF/2012/18).
19. The expert from ETRTO proposed to amend the snow test method for C3 tyres (ECE/TRANS/WP.29/GRB/2012/11). However, GRB argued that some of the proposed amendments could conflict with the recommended introduction of blocking differential on driven axle as increasing repeatability in the test. GRB agreed to resume consideration of the proposal at its next session on the basis of an official document submitted to the March 2013 sessions of WP.29 and AC.1, incorporating possible changes (see ECE/TRANS/WP.29/GRRF/2012/19) agreed by GRRF at its September 2012 session.
20. The expert from the Netherlands introduced ECE/TRANS/WP.29/GRB/2012/15 and ECE/TRANS/WP.29/GRB/2012/18 updating the test track provisions to ISO 10844:2011. The expert from ETRTO introduced similar amendments (ECE/TRANS/WP.29/GRB/2012/9) but without transitional provisions. GRB agreed that the introduction of new provisions for the test track should refer to a new series of amendments of the UN Regulation. Following the suggestion of the Chair and Vice-Chair, GRB considered GRB-56-20 (superseding ECE/TRANS/WP.29/GRB/2012/15, ECE/TRANS/WP.29/GRB/2012/18 and ECE/TRANS/WP.29/GRB/2012/9) drafted in accordance with ECE/TRANS/WP.29/1044/Rev.1 “Guidelines on the scope, administrative provisions and alternative requirements in Regulations annexed to the 1958 Agreement”. GRB requested the secretariat to distribute GRB-56-20 with an official symbol at its February 2013 session and agreed to refer to it as a basis to continue discussion on this subject.
21. Finally, GRB considered GRB-56-02 tabled by the expert from the Russian Federation aimed at providing detailed elaboration of the concept of tyre deceleration (dω/dt) in the test technology. The secretariat was requested to distribute it with an official symbol at its February 2013 session, pending the clarification of the reference to the “deceleration calculator” mentioned in the proposal.
15. GRB resumed discussion on ECE/TRANS/WP.29/GRB/2012/11, amended by GRB-57-03. The expert from EC expressed reservation on the term of differential lock that could lead to misconception. GRB endorsed the reservation of the expert from EC and agreed to inform GRRF.