Document ID: chunk:federal_register_of_legislation:F2018L01517:reg:30:p8
Version: federal_register_of_legislation:F2018L01517
Segment Type: reg
Provision Reference: reg 30 (pt 8/12)
Character Range: 34885–37496

configuration" (see paragraph 3.1.12.) symbol "A", the nominal section height H is equal to:
 H = 0.5 (D-d), rounded to the nearest mm - for references see paragraph 6.1.2.1.
6.1.5.2. For other sizes, not listed in Annex 5
 "H" and "d" are as defined in paragraph 6.1.2.1.
6.1.5.3. Coefficients "a" and "b" are respectively:
6.1.5.3.1. Coefficient "a" = .97
6.1.5.3.2. Coefficient "b"   Radial  Diagonal
 For normal use tyres   1.04  1.07
 For special use tyres   1.06  1.09
6.1.5.3.3. For snow tyres the outer diameter shall not exceed the following value
Dmax,snow = 1.01 • Dmax  rounded to the nearest mm
where Dmax is the maximum outer diameter established in conformity with the above.
For tyres of the category of use, "snow tyre" the outer diameter (Dmax) established in conformity with the above may be exceeded by one per cent.
6.2. Load/speed endurance test
6.2.1. Each type of tyre shall undergo at least one load/speed endurance tests carried out by the procedure described in Annex 7 to this Regulation.
6.2.2. A tyre which, after undergoing the endurance test, does not exhibit any tread separation, ply separation, cord separation, chunking or broken cords shall be deemed to have passed the test.
6.2.3. The outer diameter of the tyre, measured six hours after the load/speed endurance test, must not differ by more than 3.5 per cent from the outer diameter as measured before the test.
6.2.4. Where application is made for the approval of a type of tyre for the load/speed combinations given in the table in Annex 8, the endurance test prescribed in paragraph 6.2.1. above need not be carried out for load and speed values other than the nominal values.
6.2.5. Where application is made for the approval of a type of tyre, which has a load/speed combination in addition to the one that is subject to the variation of load with speed given in the table in Annex 8, the endurance test prescribed in paragraph 6.2.1. above shall also be carried out on a second tyre of the same type at the additional load/speed combination.
6.3. Tread pattern of a tyre
6.3.1. In order to be classified as a "special use tyre" a tyre shall have a block tread pattern in which the blocks are larger and more widely spaced than for normal tyres and have the following characteristics:
For C2 tyres: a tread depth ≥ 11 mm and void to fill ratio ≥ 35 per cent
For C3 tyres: a tread depth ≥ 16 mm and void to fill ratio ≥ 35 per cent
6.3.2. In order to be classified as a 'professional off-road tyre', a tyre shall have all of the following characteristics:
                  (a) For C2 tyres:
                   (i) A