Document ID: chunk:federal_register_of_legislation:F2018C00788:reg:60:p7
Version: federal_register_of_legislation:F2018C00788
Segment Type: reg
Provision Reference: reg 60 (pt 7/11)
Character Range: 40300–43159

as specified in paragraph 3. of Annex 7. The second test may be carried out on the same sample if the manufacturer agrees.

         6.2.2.  A tyre which after undergoing the load/speed test does not exhibit any tread separation, ply separation, cord separation, chunking or broken cords shall be deemed to have passed the test.

         6.2.2.1. However, a tyre marked with the speed symbol "Y" which, after undergoing the relevant test, exhibits superficial blistering of the tyre tread caused by the specific test equipment and conditions, is deemed to have passed the test.

         6.2.2.2. If a "run flat system" tyre which, after undergoing the test as specified in paragraph 3. of Annex 7, does not exhibit a change in the deflected section height, compared to the deflected section height at the start of the test, higher than 20 per cent and retains the tread connected to the two sidewalls, it is deemed to have passed the test.

         6.2.3.  The outer diameter of the tyre, measured six hours after the load/speed performance test, must not differ by more than  3.5 per cent from the outer diameter as measured before the test.

         6.3.  Tread-wear indicators

         6.3.1.  The pneumatic tyre shall include not less than six transverse rows of wear indicators, approximately equally spaced and situated in the principal grooves of the tread.  The tread-wear indicators shall be such that they cannot be confused with the rubber ridges between the ribs or blocks of the tread.

         6.3.2.  However, in the case of tyres of dimensions appropriate for mounting on rims of a nominal diameter of 12 or less, four rows of tread-wear indicators shall be accepted.

         6.3.3.  The  tread-wear indicators  must  provide  a means of  indicating,  with  a  tolerance of +0.60/-0.00 mm, when the tread grooves are no longer more than 1.6 mm deep.

         6.3.4.  The height of tread-wear indicators is determined by measuring the difference between the depth, from the tread's surface, to the top of the tread-wear indicator and to the bottom of the tread groove close to the slope at the base of the tread-wear indicator.

         7.  MODIFICATIONS OF THE TYPE OF PNEUMATIC TYRE AND EXTENSION OF APPROVAL

         7.1.  Every modification of the type of pneumatic tyre shall be notified to the Administrative Department which approved the type of pneumatic tyre.  The department may then either:

         7.1.1.  Consider that the modifications made are unlikely to have an appreciable adverse effect and that in any case, the pneumatic tyre still complies with the requirements; or

         7.1.2.  Require a further test report from the Technical Service responsible for conducting the tests.

         7.2.  A modification of the tread pattern of the tyre shall not be considered to necessitate a repetition of the tests