| 摘要 |
Tyre having a load index LI, as defined in the ETRTO Standards Manual 2010, lying in the range between 65 and 105, the tyre comprising: two beads (20), two sidewalls (30) extending the beads radially towards the outside, the two sidewalls coming together in a crown (25) comprising a crown reinforcement (80, 90), radially surmounted by a tread (40) provided with a tread pattern formed by motifs in relief, the tread having a maximum value of tan delta at 23°C and 10 Hz between 0.1 and 0.4, and a Shore A hardness between 55 and 65; an under layer (48) extending over the whole width of the tread and having an average radial height that is greater than 20% of the average radial height of the tread and a maximum value of tan delta at 23°C and 10 Hz that is less than the corresponding value of the tread; at least one radial carcass reinforcement (60) extending from the beads across the sidewalls as far as the crown; the tyre having an outside diameter OD and a nominal section width SW, as defined in the ETRTO Standards Manual 2010, in such a way that the following inequality is satisfied: OD/SW > -0.00082641 LI2+0.11266 LI -0.185; wherein the average depth of the tread pattern is greater than or equal to 4.5 mm and less than or equal to 7 mm; and wherein the voluminal cavity ratio of the tread pattern is greater than or equal to 15% and less than or equal to 25%; wherein the transverse radius (RT) of the tread is greater than or equal to the nominal section width SW. |
