Document ID: chunk:federal_register_of_legislation:F2018L01517:reg:30:p7
Version: federal_register_of_legislation:F2018L01517
Segment Type: reg
Provision Reference: reg 30 (pt 7/12)
Character Range: 32505–35116

expressed in millimetres;
                  H is the nominal section height rounded to the nearest millimetre and is equal to
                  H = S1 • 0.01 Ra, where
S1 is the nominal section width in millimetres;
                  Ra is the nominal aspect ratio;
all as shown on the sidewall of the tyre in the tyre-size designation in conformity with the requirements of paragraph 3.4. above.
6.1.2.2. However, for the existing types of tyres whose designation is given in the first column of the tables in Annex 5 to this Regulation, the outer diameter shall be deemed to be that given opposite the tyre designation in those tables.
6.1.2.3. However, for tyres identified by the "tyre to rim fitment configuration" (see paragraph 3.1.12.) symbol "A", the outer diameter shall be that specified in the tyre-size designation as shown on the sidewall of the tyre.
6.1.3. Method of measuring tyres
 The dimensions of tyres shall be measured by the procedure described in Annex 6 to this Regulation.
6.1.4. Tyre section width specifications
6.1.4.1. The overall width of a tyre may be less than the section width or widths determined pursuant to paragraph 6.1.1. above.
6.1.4.2. It may exceed that value by 4 per cent in case of radial-ply tyres and by 8 per cent in the case of diagonal (bias-ply) tyres.  However, for tyres with nominal section width exceeding 305 mm intended for dual mounting (twinning), the value determined pursuant to paragraph 6.1.1. above shall not be exceeded by more than 2 per cent for radial-ply tyres with nominal aspect ratio higher than 60, or 4 per cent for diagonal (bias-ply) tyres. The respective limits shall be rounded to the nearest millimetre (mm).
6.1.4.3. However, for tyres identified by the "tyre to rim fitment configuration" (see paragraph 3.1.12.) symbol "A", the overall width of the tyre, in the lower area of the tyre, equals the nominal width of the rim on which the tyre is mounted, as shown by the manufacturer in the descriptive note, increased by 27 mm.
6.1.5. Tyre outer diameter specifications
 The outer diameter of a tyre must not be outside the values dmin and dmax obtained from the following formulae:
Dmin = d + 2 • Hmin
Dmax = d + 2 • Hmax
where:
Hmin = H • a rounded to the nearest mm
Hmax = H • b rounded to the nearest mm
6.1.5.1. For sizes listed in Annex 5 and for tyres identified by the "tyre to rim fitment 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