UN R109 — Supplement 11 to the 00 series of amendments

Paragraph 2.8.2. now adds that special use tyres “are primarily designed to initiate and maintain the vehicle in motion in off-road conditions”. New paragraph 2.8.4. defines a “Traction tyre” as “a tyre in class C2 or C3 bearing the inscription TRACTION and intended to be fitted primarily to the drive axle(s) of a vehicle to maximize force transmission in various circumstances”. New paragraphs 2.58. to 2.60. define “Professional off-road tyre”, “Tread depth”, “Principal grooves” and “Void to fill ratio”. To be classified as a “traction tyre”, a tyre must have “a tread pattern with minimum two circumferential ribs, each containing a minimum of 30 block-like elements, separated by grooves and/or sipe elements the depth of which has to be minimum of one half of the tread depth” (paras. 7.3. and 7.3.1.). To be classified as a “special use tyre” (para. 7.4.) or “professional off-road tyre” (para. 7.5.), a tyre needs a tread depth ≥ 11 mm (C2) or ≥ 16 mm (C3). Both paragraphs also set a void to fill ratio ≥ 35 per cent, and paragraph 7.5. adds a maximum speed rating ≤ Q (C2) or ≤ K (C3).

Paragraph 3.2.13. now covers the inscription “MPT” (or alternatively “ML” or “ET”) and/or “POR” if the tyre is classified in the category of use “special”. New paragraph 3.2.18. adds the inscription “TRACTION” if the tyre is classified as traction, with new footnote 10 on the minimum height of marking. Under paragraph 3.5., the markings of paragraph 3.2. and the approval mark must now be “clearly legible and indelible”, in place of “clearly legible”. They must be “raised above or sunk below the tyre surface” or permanently marked on to the tyre, in place of “moulded on to or into the tyre”. New paragraph 3.5.1. is “[Reserved]”, and under new paragraph 3.5.2. a date of manufacture that is not moulded must be applied “not later than 24 hours after the tyre is removed from the mould”. Annex 3 now has Example 1, Example 2, new footnotes, dimensional requirements for further markings and new item (f) on two test inflation pressure indications.

Paragraph 2.7.3. now names the tyre structure “Radial” or “radial-ply”, in place of “Radial”. Paragraph 2.26. now excepts types of tyre for which the tyre-size designation is shown in the first column of the tables in Annex 5. Before, paragraphs 2.26.1. and 2.26.2. each gave this exception. New paragraphs 2.26.3. to 2.26.3.2. add an indication of the structure placed in front of the rim diameter marking. This is a dash or the letter “D” on diagonal (bias-ply) tyres, and the letter “R” on radial-ply tyres. Former paragraphs 2.26.3., 2.26.3.1. and 2.26.4. are now paragraphs 2.26.4., 2.26.4.1. and 2.26.5.

Paragraph 6.4.4.1. now also covers “an identical tread pattern design in a mould cure product”, and paragraph 4.1.5.3.1.1. now covers “either pre-cured or mould cure tread material”. Under paragraphs 6.4.4.1. and 6.4.4.2., the documents now go to the TAA and the Technical Service issuing the approval, and optionally to the retreader. The former separate lines “To the retreader” are deleted. New paragraph 6.4.4.3. covers tyres retreaded “by using mould cure tread material(s) and design(s) not covered by paragraphs 6.4.4.1. or 6.4.4.2.” that have to fulfil paragraph 7.2. For these tyres, the retreader must provide to the TAA and the Technical Service issuing the approval the documents in items (a) to (d). Paragraphs 4.1.5.3.1.3., 5.4., 9.2.2., 9.4. and 9.4.2. now refer to paragraph 6.4.4.3.

Paragraph 2.52. now refers to the standards of ASTM International and lists four SRTTs: “SRTT16C”, “SRTT19.5”, “SRTT22.5” and “SRTT16”. Before, the list had E1136-93 (2003) for the size P195/75R14 and the other three standards with “(2011)”. In the table of paragraph 7.2.1., the reference tyre “SRTT14” is replaced by “SRTT16”. Paragraph 2.54. now defines the snow grip index (“SG”) as the snow grip performance of a candidate tyre relative to that of the applicable SRTT. Before, it was the ratio between the performance of the candidate tyre and the performance of the standard reference test tyre. In Annex 10, Appendix 2, item 7 of the report now reads “Snow grip index SG”, and the test data table adds a “Factor f” row.

Before, paragraph 6.4.10. permitted upgrading of the service description only for the first retread of an original, first life tyre. It now also permits upgrading for a used casing, if the traceability of the carcasses to be retreaded is guaranteed (item (b)). The speed symbol or load index used for retreading must then “not exceed the conditions mentioned in the standard form in Annex 9 of UN Regulation No. 54 for these carcasses”. For a used casing whose traceability is not guaranteed till the original, first life, tyre, “the speed symbol or the load index shall then not be raised above that shown on the used casing” (item (c)). The retreader must demonstrate to the approval authority the traceability of retreaded carcasses. The former sentence on tyres which have been previously retreaded is deleted.

Under paragraph 7.1.4.4., the additional sidewall protective rubber layer (ASP) rule now applies to retreaded C3 radial tyres. Before, it applied to retreaded radial tyres “with nominal section width exceeding 305 mm for dual mounting (twinning) and a nominal aspect ratio higher than 60”. New item (d) says: “In case of a dual mounting (twinning) only one tyre with ASP is allowed and has to be mounted on the outer wheel position”.