Document ID: chunk:federal_register_of_legislation:F2018L01517:reg:30:p6
Version: federal_register_of_legislation:F2018L01517
Segment Type: reg
Provision Reference: reg 30 (pt 6/12)
Character Range: 29915–32774

the course of production of a particular tyre type, the manufacturer has obtained a new approval for that same tyre type to be marked with a service description indicating a higher load index or different speed symbol than the earlier marking and where the tyre manufacturer authorizes the earlier tyre type to be re-treaded and marked with the later service description, the tyre manufacturer shall complete the Communication document given in Annex 9 to this Regulation and shall submit this to the Type Approval Authority that has granted the new approval.  If the authorization for upgrading only applies to tyres from a particular manufacturing plant, or produced during particular production periods, the information necessary to identify the tyres shall be stated on the Communication document.
The Type Approval Authority shall communicate this information to other Parties to the Agreement, which apply this Regulation, and tyre manufacturers or Type Approval Authorities shall release this information on the request of any re-treading production unit that is approved in accordance with Regulation No. 109.
6. Specifications
6.1. Dimensions of tyres
6.1.1. Section width of a tyre
6.1.1.1. The section width shall be obtained by means of the following formula:
S = S1 + K (A - A1),
                     Where:
                  S is the "section width" rounded to the nearest millimetre and measured on the measuring rim;
                  S1 is "the nominal section width" in millimetres, as shown on the sidewall of the tyre in the tyre designation as prescribed;
                  A is the width of the measuring rim in millimetres, as shown by the manufacturer in the descriptive note; and
A1 is the width of the theoretical rim in millimetres.
A1 shall be taken to equal S1 multiplied by the factor x as specified by the manufacturer, and K shall be taken to equal 0.4.
6.1.1.2. 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 section width shall be deemed to be that given opposite the tyre designation in those tables.
6.1.1.3. However, for tyres identified by the "tyre to rim fitment configuration" (see paragraph 3.1.12.) symbol "A", K shall be taken to equal 0.6.
6.1.2. Outer diameter of a tyre
6.1.2.1. The outer diameter of a tyre shall be obtained by means of the following formula:
D = d + 2H
                     where:
                  D is the outer diameter expressed in millimetres;
                  d is the conventional number defined in paragraph 2.20.1.3. above, 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