Document ID: chunk:federal_register_of_legislation:F2018L01518:reg:30:p1
Version: federal_register_of_legislation:F2018L01518
Segment Type: reg
Provision Reference: reg 30 (pt 1/2)
Character Range: 16855–19839

30                                      762

2.24. "Rim" means the support for a tyre-and-tube assembly, or for a tubeless tyre, on which the tyre beads are seated;2/

2.24.1. "Tyre to rim fitment configuration" means the type of rim to which the tyre is designed to be fitted.  In the case of non-standard rims this will be identified by a symbol applied to the tyre, for example, "CT", "TR", "TD", "A" or "U".

2.25. "Theoretical rim" means the notional rim whose width would be equal to x times the nominal section width of a tyre. The value of x shall be specified by the manufacturer of that tyre;

2.26. "Measuring rim" means the rim on which a tyre is required to be fitted for size measurements;

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

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

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

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

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

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

2.33. "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.

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

2.34.1. The categories of speed are those indicated in the table below:

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

2.35. Tread pattern grooves

2.35.1. "Principal grooves" means the wide circumferential grooves positioned in the central zone of the tyre tread, which have the tread-wear indicators located in the base.

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

2.36. "Void to fill ratio" means the ratio between the area of voids in a reference surface and the area of this reference surface calculated from the mould drawing.

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

2.37.1. 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;

2.37.2. 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