Draft proposal concerning communications with a towed vehicle.

Proposal for amendments that allows for tyre marking methods other than moulding.

Proposal to

1. Change the definition of the tyre size designation by including prefixes and suffixes as well as the code for the tyre structure
2. Clarify the use of sizes listed in Annex 5
3. Move the definition of “reinforced” into a paragraph that is not subordinated to the definition of “Structure of a tyre”
4. Correct references and typographical errors
5. Rearrange paragraphs and amendments in order to increase readability
6. Delete an unnecessary cross-reference to UN Regulation No. 54
7. Change the definition of “bias-belted”
8. Amend the definition of “snow tyres” by replacing “ordinary (road-type) tyres” (which is not defined) by “normal tyre”, removing the note that snow tyres generally have more widely spaced ribs or blocks
9. Include a general provision addressing the gap between the effective date of entry into force and the date of notification of the adoption of the Supplement to the Contracting Parties
10. Keep the restriction of measurement of overall diameter after load/speed test only to diagonal tyres (For radial the variation of outer diameter of the tyre, measured six hours after the load/speed performance test as specified in paragraph 2 of Annex 7, is far below ±3.5 per cent from the outer diameter as measured before the test.)
11. Remove use of the word “moulding”
12. Resolve conflicting provisions in Annex 2 concerning the minimum size of the approval mark
13. Clarify that mounting motorcycle tyres on motorcycle rims is the standard configuration and that “M/C” marking is optional for the sizes listed in Annex 5.

Proposal for alternative language regarding markings to avoid use of the term “moulded” which could be interpreted as a technical design restriction and to add a reference to “log-skidder” tyres.

Proposal to align with the provisions of European Union Regulation 2019/2144 and to introduce the TPMS requirements for all vehicle categories.

Proposal to align with the provisions of European Union Regulation 2019/2144 and to introduce the tyre installation requirements for all vehicle categories.

1. Improve the reproducibility of the test method (in alignment with ISO 23671)
2. Include maximum load and pressure information per ASTM F2493-19
3. Update the test report templates accordingly
4. Remove the limitation for “moulded” markings
5. Transition from SRTT14 to SRTT16
6. Align track friction requirements for track characterization per the transition
7. Clarify vehicle selection provisions
8. Introduce transitional provisions

Proposal to expand the scope of the activity to include C2 and C3 tyres.

Proposal from the TPMSTI task force to revise the communication interface protocol of TPMS between towing and towed vehicles of categories N2, N3 and O3, O4, respectively (described in Annex 5 on the basis of the ISO bus requirements) in alignment with UN R13 and ISO updates. The proposal further corrects and clarifies provisions across TPMS, TPRS and CTIS.

Proposal to include requirements for wet grip of tyres of classes C2 and C3 in worn state to the scope of the working group activities.

Overview of UTAC CERAM testing designed to consider the impact of additional tightening of tyre performance limits on the balance
between legal requirements (rolling resistance, wet grip and rolling sound emission) and other performance aspects not subject to legal requirements.