Patent ID: 9688103
Date: 2017-06-27
CPC Classifications: B60C

Claim:
1. A motorcycle tire comprising a tread portion provided with tread grooves defining a unidirectional tread pattern having an intended tire rotational direction, the tread grooves including a center main groove and a plurality of main oblique grooves each with a branch groove, wherein the center main groove extends along the tire equator continuously in the tire circumferential direction, the main oblique grooves are disposed on both sides of the center main groove so that each of the main oblique grooves has an axially inner end at a distance from the center main groove and extends axially outwardly from the axially inner end, wherein each of the axially inner ends of the main oblique grooves is positioned at an axial distance from the tire equator in a range of not less than 5% and not more than 15% of the developed half tread width so that the axially inner ends of the main oblique grooves are positioned within a zero-chamber ground contact width, and each of axially outer ends of the main oblique grooves is positioned at the tread edge so that the axially outer ends of the main oblique grooves are positioned outside the zero-chamber ground contact width, the main oblique grooves extend from their axially inner ends to axially outer ends, while inclining to the opposite direction to the intended tire rotational direction over their respective entire lengths, at an angle of from 30 to 45 degrees with respect to the tire circumferential direction, the branch groove is branched off from the main oblique groove and extends toward the opposite direction to the intended tire rotational direction, while inclining to the axially inside, and terminates at a distance from the center main groove without being connected thereto, a branch point of the branch groove from the main oblique groove, which is defined by an intersecting point between widthwise center lines of the main oblique groove and the branch groove, is in a range between 40% and 60% of the developed half tread width from the tire equator, wherein the branch groove is a bent groove made up of a first inclined part extending from the main oblique groove at a substantially constant angle θ in a range from 30 to 45 degrees with respect to the tire circumferential direction, and a second inclined part extending at a substantially constant angle δ in a range from 5 to 20 degrees with respect to the tire circumferential direction, on each side of the center main groove, a single sub oblique groove shorter than the main oblique grooves, is disposed between every two of the main oblique grooves so that the sub oblique grooves are inclined to the same direction as the main oblique grooves, and on each side of the tire equator, when the developed half tread width is axially equally divided into five portions, the land ratio of each of the five portions is in a range of 75% to 85%.