UN Regulation No. 54
Commercial Vehicle Tyres

Series of Amendments, Supplements, and Corrigenda

Proposal adopted by the GRRF to harmonize the definitions used in UN R54 with the amendments (ECE/TRANS/WP29/2010/63) to UN R117 approved by the World Forum at its June 2010 session.

Proposal to incorporate additional tire sizes within the regulation for commercial vehicle tires sold in countries requiring type approval according to UN Regulation No. 54. This proposal was adopted by the GRRF at its 75th session based upon a proposal by the ETRTO (document GRRF/2013/19).

No objections to the proposal which is passed for consideration to adopt during the AC.1 session.

Proposal to permit the “LT” marking as a prefix or suffix to align the requirements with the current practice for C2 tyres with metric size designation. The proposed text for a prefix is in line with the latest draft of the gtr on tyres. The proposed text for a suffix is necessary for tyres designed to Japan Automobile Tyre Manufacturers Association (JATMA) standards. The proposal would add new tyres for light commercial vehicles (high flotation tyres) in Annex 5 of UN Regulation No. 54.

Proposal to:

• correct the code 19 rim diameter, amend the tyre dimension requirements,
• modify the marking requirements to replace PSI with kilopascals (“kPa”),
• change the measurement units for drum speed from min-1 to km.h-1 and align the wording in Annex 7, Appendix 1 with the text of the Regulation,
• add new tyre sizes to Annex 5, allow for special tyres that can also be used as snow tyres to be marked with the inscription M+S, M.S, or M&S while remaining in the category of use “special”,
• align definitions and content with the other tyre regulations (UN Regulations Nos. 30, 117, 75 etc.),
• include a definition of “manufacturer” extracted from the resolution “R.E.3”
• adopt a common definition and use of the terms “Manufacturer’s name”, “Brand name”, “Trademark”, “Trade description” and “Commercial name” and their links, and
• add information in the certificate to enable approval authorities to more easily understand the products the certificate addresses.

58. Agenda item 4.9.4., in ECE/TRANS/WP.29/2016/52, amend the title of the document to read: “Proposal for Supplement 21 to Regulation No. 54”, amend the title on page 2, to read: “Supplement 21 to Regulation No. 54 (Tyres for commercial vehicles and their trailers)”

Proposal to introduce formulae for tyre sizes in Annex 5, Table B, add sizes in Annex 5, Part II, Tables C and E for old sizes that do not follow the guidelines/formulae applicable for high flotation tyres, amends footnotes in Annex 5, Part II, Table B in order to clarify categories of use, clarify tyre width tolerances, correct paragraph numbering and references, align the text editorially with UN R30 and to make other editorial improvements.

Proposal to

• Clarify the minimum heights for markings of tyres with nominal rim diameter codes ≥ 20 and nominal section width ≤ 235
• Clarify the minimum heights for markings of tyres with nominal rim diameter codes < 20 and nominal section width > 235
• Correct the use of uppercase letters to denote dimensions where lowercase letters had been inserted
• Correct the paragraph numbering pursuant to the adoption of Supplement 21
• Delete a redundant note at the end of paragraph 6.1.5.3.3., and
• Add specifications for tyre sizes 33×11.50R20LT, 35×11.50R17LT, 37×13.50R26LT, 36×15.50R20LT and 40×15.50R26LT.

Proposal from GRBP to clarify the use of an additional load/speed combination for a tyre type, to consolidate the calculation of reference dimensions with that provided in GTR 16, and to avoid placing requirements in the Definitions section and otherwise improving the text via use of the term “service description” (as introduced in Supplement 24).

Proposal to introduce amendments addressing the following:

1. “Special use” tyres with nominal rim diameters larger than those listed in the present table (rim diameters up to 42, section widths up to 750 mm and overall diameters over 2 meters) and with speed symbols F and above have been announced in the European market as original equipment of N3G “special purpose vehicles” (i.e., special high speed self-propelled vehicles for agricultural and forestry use, like wood choppers).

2. Existing multi-purpose tyres (MPT) (classified as “special use tyres” as per paragraphs 2.5.3. and 3.1.13.), already type approved since years, have a tread pattern with lugs or cleats in addition to those with blocks, as evidenced by the attached slide showing some examples. It is proposed to amend paragraph 6.3.1. by clarifying that lugs and cleats are possible shapes of the mentioned blocks.

3. Testing tyres with very large overall diameters, sometimes over 2 m, on a test drum with a diameter of 1.70 m ± 1 % would be unpracticable. For practical reasons most of those tyres are regularly tested on drums with a diameter of 3 m or even larger. The proposal carries equivalence provisions from UN R106 to justify the equivalence of the test method as required by Annex 7 in point 4 “Equivalent test methods" and clarifies based on UN R117 the formula already used indirectly.

4. Some commercial vehicles are often used in the market at a reduced speed of 70 km/h with a load-capacity of the tyres increased as per load/speed combination defined in the table of Annex 8. The proposal would allow use of the speed category symbol E (but restrict it to “additional service description”) to provide this information.

5. Considering that 32 km/h is already a floor value for the test-drum speed for diagonal tyres, ETRTO proposes not to apply to E speed category symbol tyres the linear decrease of the test-drum speed in function of the decrease of the speed category symbol by keeping, for safety reasons, the same test-drum speed as for F speed category symbol tyres, i.e., 32 km/h).

6. In the case of additional service descriptions mentioned in paragraph 6.2.5.1., it is proposed not to perform the additional load/speed test because the load-capacity approximates with a negligeable difference the reduction or the increase in percentage of the nominal load/speed combination applicable to the nominal speed category symbol (see Annex 8). An example of the actual differences (in percentage and in absolute value) is provided.

7. Type approval applications for radial tyres with load capacity index greater or equal to 122 and without the additional marking “LT”, or “C” have been done in the past for the speed category symbol N for which the load/speed endurance test procedure is not described in Annex 7, Appendix 1. To type approve such tyres the test speed was separately defined by the different involved Type Approval Authorities. In order to harmonize the test procedure to be used for the type approval of such tyres, it is proposed to amend the Annex 7, Appendix 1 by introducing testing conditions in line with the rule applied for defining the test speed of radial tyres with load capacity index greater or equal to 122 (i.e. starting from 32 km/h set for F speed category symbol, the test speed is increased by 8 km/h respect to the one set for the previous speed category symbol).

8. The definition of “snow tyre” is amended to clarify that “snow tyres” are not only suitable for the use in snow conditions but also on mud and by replacing the term “maintain vehicle motion” (i.e. keeping the vehicle speed and direction of movement constant) by a more general concept of “controlling vehicle motion” (i.e. also being able to change the vehicle speed and direction of movement as intended).

9. It is proposed to explicitly allow other technical measurement solutions of the tyre overall width by removing the words “by caliper” which fix a technical limitation. The removal of this technical limitation would be advisable following the principle of not stopping the technical innovations.

Proposal To specify a tolerance for the maximum overall width of tyres identified by the “tyre to rim fitment configuration” symbol A.

Proposal to align Annex 9 with Annex 1 (paragraphs 5., 6. and 7.) and to enable type approval authorities to make the connection with the relevant reports.