Document ID: chunk:federal_register_of_legislation:F2018L01518:front:0:p5
Version: federal_register_of_legislation:F2018L01518
Segment Type: other
Provision Reference: 
Character Range: 12933–15647

tyre on it;[2]/

2.10. "Cord" means the strands forming the fabric of the plies in the pneumatic tyre;2/

2.11. "Ply" means a layer of rubber-coated parallel cords;2/

2.12.  "Carcass" means that part of a pneumatic tyre other than the tread and the rubber side walls which, when inflated, bears the load;2/

2.13. "Tread" means that part of a pneumatic tyre which comes into contact with the ground;2/

2.14. "Side wall" means the part of a pneumatic tyre between the tread and the bead;2/
2.15. "Lower area of tyre" means the area included between the point of maximum section width of the tyre and the area designed to be covered by the edge of the rim;2/

2.15.1. However, in case of tyres identified by the "tyre to rim fitment configuration" (see para. 3.1.13.) symbol "A" or "U", it means the area of the tyre which is seating on the rim.

2.16. "Tread pattern groove" means the space between two adjacent ribs or blocks in the tread pattern;2/

2.17. "Section width" means the linear distance between the outsides of the side walls of an inflated pneumatic tyre, excluding elevations due to labelling (marking), decoration or protective bands or ribs;2/

2.18. "Overall width" means the linear distance between the outsides of the side walls of an inflated pneumatic tyre, including labelling (marking), decoration and protective bands or ribs;2/

2.19. "Section height" means a distance equal to half the difference between the outer diameter of the tyre and the nominal rim diameter;2/

2.20. "Nominal aspect ratio (Ra)" means the centuple of the number obtained by dividing the number expressing the section height in mm by the number expressing the nominal section width in mm;

2.21. "Outer diameter" means the overall diameter of an inflated new pneumatic tyre;2/

2.22. "Tyre-size designation" is

2.22.1. a designation showing:

2.22.1.1. the nominal section width.  This width must be expressed in mm, except in the case of the types of tyre for which the size designation is shown in the first column of the tables in Annex 5 to this Regulation;

2.22.1.2. the nominal aspect ratio except in the case of certain types of tyre, for which the size designation is shown in the first column of the tables in Annex 5 to this Regulation, or, depending on the tyre design type, the nominal outer diameter expressed in mm;

2.22.1.3. a conventional number denoting the nominal rim diameter and corresponding to its diameter expressed either by codes (numbers below 100) or in millimetres (numbers above 100);

2.22.1.4. the letter "T" in front of the nominal section width in case of T‑type temporary use spare tyres;

2.22.1.5. an indication of the tyre to rim fitment configuration when it differs from