UN R30 — Supplement 21 to the 02 series of amendments

New paragraph 2.11. defines an “Extended Mobility Tyre (EMT)”. An EMT has a radial structure that allows the tyre to provide the vehicle with the basic tyre functions in flat tyre running mode. This applies with the tyre mounted on the appropriate wheel and in the absence of any supplementary component. The tyre provides these functions at a speed of 80 km/h and a distance of 80 km. New paragraph 3.1.15. adds to paragraph 3.1. a symbol for a tyre that is an EMT, where “h” is at least 12 mm. The application for approval must specify whether the tyre is an EMT (new paragraph 4.1.9.), and Annex 1 has a new item 4.6.

For EMT type approval, another load/speed test must be carried out on a second sample, as specified in new paragraph 4. of Annex 7. The second test may be carried out on the same sample if the manufacturer agrees (new paragraph 6.2.1.3.). In this test, the tyre runs fully deflated, with 60 per cent of the maximum load rating corresponding to its load capacity index. The test room temperature is 25 ºC ± 3 ºC. The test speed is 80 km/h on a 2.0 m ± 1 per cent drum or 75 km/h on a 1.7 m ± 1 per cent drum. An EMT passes if its deflected section height changes by 20 per cent or less and the tread stays connected to the two sidewalls.

Annex 7, paragraph 3., is now the procedure to assess the “flat tyre running mode” of “run flat tyre”, in place of “run flat system”. In paragraph 3.1., the test rim now has a measuring rim width according to ISO 4000-1, in place of the rim specified by the manufacturer. It also has a contour with hump (round or flat) on both rim sides, according to ISO 4000-2. Paragraph 3.2. adds that the temperature sensor must be not less than 0.15 m and not more than 1.00 m from the tyre sidewall. The test speed in paragraph 3.8.2. is 80 km/h for a 2.0 m drum or 75 km/h for a 1.7 m drum (± 1 per cent).

Paragraphs 6.2.1.2. and 6.2.2.2. now say “run flat tyre” in place of “run flat system”. The definition of “Run flat system” or “Extended mobility system” in former paragraph 2.40. is deleted. For the load and speed conditions marked on the tyre, paragraph 6.2.1.2. now refers to paragraphs 3.1.5. and 3.1.8., in place of paragraph 3.1.4.1. In the table of Annex 7, paragraph 1.2., the title of the third column is now “Radial and Run flat tyres”. In Annex 6, paragraph 1.2.3. now reads “in standard radial tyres and in standard Run Flat tyres: to 1.8 bar”. Paragraph 1.2.4. now reads “in reinforced radial tyres and in reinforced Run Flat tyres: to 2.2 bar”, in place of “In reinforced tyres”.

New paragraphs 2.25.3. to 2.25.3.5. add “An indication of the structure” to the tyre-size designation of paragraph 2.25. They give the letter placed in front of the rim diameter marking for each structure, for example “R” on radial-ply tyres. Paragraphs 3.1.4. to 3.1.4.5. on the indication of the structure are deleted. Paragraph 3.1.5.1. no longer contains the “ZR” requirement for tyres suitable for speeds in excess of 300 km/h; new paragraph 2.25.3.4. contains it. New paragraph 2.25.6. adds, as an option, the letter “P” in front of the nominal section width. Annex 3, paragraph 3.(a) now also shows the examples “P185/70 R 14” and “T185/70 R 14”.

In paragraph 2.1.(d), the list of structures now reads “radial (radial-ply)” in place of “radial-ply”. Paragraph 2.9.3. now gives the term “radial-ply” next to “Radial”. In paragraph 2.10., the definition of “Reinforced” or “Extra Load” now says “a tyre” in place of “a tyre structure”. In paragraph 2.9.4., the “Run flat tyre” definition no longer gives “(50mph)” after the speed of 80 km/h. In the “Deflected section height” definition of paragraph 2.43., the nominal rim diameter is now as defined in paragraph 2.26., not in ISO 4000-1.

Many paragraphs have new numbers, for example former paragraphs 2.9. to 2.15. are now 2.12. to 2.18. In paragraph 4.1., former paragraphs 4.1.9. to 4.1.16. are now 4.1.10. to 4.1.17. Cross-references are updated to the new numbers, for example “3.1.10.” is replaced with “2.27.1.” in paragraph 6.1.1.3. The references in Annex 6, paragraph 1.1., and in Annex 7, paragraphs 1.1., 2.2.2. to 2.2.4., 2.5.2. and 2.6.1., are updated too. In Annex 7, the paragraph “Equivalent test methods” is now paragraph 5., in place of paragraph 4. Its text now refers to a method other than that described in paragraphs 2. and/or 3., and/or 4.