Document ID: chunk:federal_register_of_legislation:F2018C00788:front:0:p7
Version: federal_register_of_legislation:F2018C00788
Segment Type: other
Provision Reference: 
Character Range: 20148–22729

which a tyre is required to be fitted for size measurements;

2.22.  "Test rim" means the rim on which a tyre is required to be fitted for testing;

2.23.  "Chunking" means the breaking away of pieces of rubber from the tread;

2.24.  "Cord separation" means the parting of the cords from their rubber coating;

2.25.  "Ply separation" means the parting of adjacent plies;

2.26.  "Tread separation" means the pulling away of the tread from the carcass;

         2.27.  "Tread-wear indicators" means the projections within the tread grooves designed to give a visual indication of the degree of wear of the tread;

         2.28.  "Load-capacity index" means a number associated to the reference mass a tyre can carry when operated in conformity with requirements governing utilization specified by the manufacturer.

         2.29.  "Speed category" means the maximum speed which the tyre can sustain, expressed by speed category symbol (see table below).

2.29.1.  The categories of speed are those indicated in the table below:
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2/ See explanatory figure.

Speed-category symbol  Maximum speed
                       (km/h)

L                      120
M                      130
N                      140
P                      150
Q                      160
R                      170
S                      180
T                      190
U                      200
H                      210
V                      240
W                      270
Y                      300

2.30.  Tread pattern grooves

         2.30.1.  "Principal grooves" means the wide grooves positioned in the central zone of the tyre tread, which have the tread-wear indicators (see para. 2.27.) located inside them.

         2.30.2.  "Secondary grooves" means the supplementary grooves of the tread pattern which may disappear in the course of the tyre's life.

         2.31.  "Maximum load rating" means the maximum mass the tyre is rated to carry;

         2.31.1.  for speed not exceeding 210 km/h the maximum load rating shall not exceed the value associated with the load capacity index of the tyre;

         2.31.2.                           for speed higher than 210 km/h, but not exceeding 240 km/h, (tyres classified with speed category symbol "V") the maximum load rating shall not exceed the percentage of the value associated with the load capacity index of the tyre, indicated in the table below, with reference to the speed capability of the car to which the tyre is fitted.

Maximum speed     Maximum load rating
(km/h)            (per cent)