Motorcycle tire set

Patent metadata

Field	Value
Publication number	US-2023271461-A1
Application number	US-202318096821-A
Country	US
Kind code	A1
Filing date	Jan 13, 2023
Priority date	Feb 28, 2022
Publication date	Aug 31, 2023
Grant date	—

Abstract

A motorcycle tire set includes a front-wheel tire and a rear-wheel tire. Each of the front and rear-wheel tires includes a carcass, a band layer arranged radially outwardly of the carcass in the tread portion, and a tread rubber arranged radially outwardly of the band layer. The carcass includes a carcass ply including carcass cords. The band layer includes a jointless band ply in which a band cord is circumferentially wound spirally at an angle equal to or less than 5 degrees. The tread rubber includes a crown rubber portion. An angle θ1 of the carcass cords of the front-wheel tire is 65 degrees or more with respect to the tire circumferential direction. A rubber hardness of the crown rubber portion of the rear-wheel tire is greater than a rubber hardness of the crown rubber portion of the front-wheel tire.

First claim

1 . A motorcycle tire set comprising:
a front-wheel tire; and a rear-wheel tire, wherein
each of the front-wheel tire and the rear-wheel tire comprises a tread portion, a toroidal carcass, a band layer arranged outwardly in a tire radial direction of the carcass in the tread portion, and a tread rubber arranged outwardly in the tire radial direction of the band layer,
the carcass comprises a carcass ply comprising a plurality of carcass cords,
the band layer comprises a jointless band ply in which a band cord is wound spirally in a tire circumferential direction at an angle equal to or less than 5 degrees, and
the tread rubber comprises a crown rubber portion disposed in a tread crown region, wherein
an angle θ1 of the plurality of carcass cords of the front-wheel tire is equal to or less than 65 degrees with respect to the tire circumferential direction, and
a rubber hardness Hc2 of the crown rubber portion of the rear-wheel tire is greater than a rubber hardness Hc1 of the crown rubber portion of the front-wheel tire.

2 . The motorcycle tire set according to claim 1 , wherein
a difference (Hc2 — Hc1) between the rubber hardness Hc2 of the crown rubber portion of the rear-wheel tire and the rubber hardness Hc1 of the crown rubber portion of the front-wheel tire is in a range from 2 to 8.

3 . The motorcycle tire set according to claim 1 , wherein
the angle θ1 of the plurality of carcass cords of the front-wheel tire is smaller than an angle θ2 of the plurality of carcass cords of the rear-wheel tire with respect to the tire circumferential direction.

4 . The motorcycle tire set according to claim 3 , wherein
a difference (θ2 - θ1) between the angle θ2 of the plurality of carcass cords of the rear-wheel tire and the angle θ1 of the plurality of carcass cords of the front-wheel tire is equal to or more than 15 degrees.

5 . The motorcycle tire set according to claim 1 , wherein
each of the front-wheel tire and the rear-wheel tire further comprises a pair of shoulder rubber portions arranged on both sides of crown rubber portions in a tire axial direction, and in the rear-wheel tire, a rubber hardness Hc2 of the crown rubber portion is different from a rubber hardness Hs2 of the pair of shoulder rubber portions.

6 . The motorcycle tire set according to claim 5 , wherein
each of the front-wheel tire and the rear-wheel tire further comprises a base rubber portion arranged inwardly in the tire radial direction of the crown rubber portion and the pair of shoulder rubber portions, and a rubber hardness of the base rubber portion of each of the front and rear wheel tires is different from the rubber hardness of the crown rubber portion and the rubber hardness of the pair of shoulder rubber portions of each of the front and rear wheel tires.

7 . The motorcycle tire set according to claim 5 , wherein
in the rear-wheel tire, the rubber hardness Hs2 of the pair of shoulder rubber portions is greater than the rubber hardness Hc2 of the crown rubber portion.

8 . The motorcycle tire set according to claim 7 , wherein
a difference (Hs2 - Hc2) between the rubber hardness Hs2 of the pair of shoulder rubber portions and the rubber hardness Hc2 of the crown rubber portion ranges from 1 to 5.

9 . The motorcycle tire set according to claim 7 , wherein
in the front-wheel tire, a rubber hardness Hc1 of the crown rubber portion is different from a rubber hardness Hs1 of the pair of shoulder rubber portions.

10 . The motorcycle tire set according to claim 9 , wherein
in the front-wheel tire, the rubber hardness Hc1 of the crown rubber portion is greater than the rubber hardness Hs1 of the pair of shoulder rubber portions.

11 . The motorcycle tire set according to claim 10 , wherein
a difference (Hc1 - Hs1) between the rubber hardness Hc1 of the crown rubber portion and the rubber hardness Hs1 of the pair of shoulder rubber portions ranges from 1 to 5.

12 . The motorcycle tire set according to claim 1 , wherein
the rubber hardness Hc1 of the crown rubber portion of the front-wheel tire ranges from 55 to 68.

13 . The motorcycle tire set according to claim 6 , wherein
a rubber hardness of the base rubber portion of each of the front and rear wheel tires ranges from 55 to 70.

14 . The motorcycle tire set according to claim 1 , wherein
the crown rubber portion of each of the front and rear wheel tires ranges from 55 to 70.

15 . The motorcycle tire set according to claim 1 , wherein
the crown rubber portion of each of the front and rear wheel tires has a width in a tire axial direction in a range from 20% to 80% of a tread width.

16 . The motorcycle tire set according to claim 3 , wherein
the angle θ1 of the plurality of carcass cords of the front-wheel tire ranges from 20 to 65 degrees, and the angle θ2 of the plurality of carcass cords of the rear-wheel tire is equal to or more than 80 degrees.

17 . The motorcycle tire set according to claim 4 , wherein
the angle θ1 of the plurality of carcass cords of the front-wheel tire ranges from 20 to 65 degrees, and the angle θ2 of the plurality of carcass cords of the rear-wheel tire is equal to or more than 80 degrees.

18 . The motorcycle tire set according to claim 17 , wherein
a difference (θ2 - θ1) between the angle θ2 of the plurality of carcass cords of the rear-wheel tire and the angle θ1 of the plurality of carcass cords of the front-wheel tire is equal or less than 60 degrees.

19 . The motorcycle tire set according to claim 17 , wherein
a difference (θ2 - θ1) between the angle θ2 of the plurality of carcass cords of the rear-wheel tire and the angle θ1 of the plurality of carcass cords of the front-wheel tire is equal or less than 30 degrees.

20 . The motorcycle tire set according to claim 1 , wherein
the band layer has a width in a tire axial direction in a range from 60% to 100% of a tread width.

Assignees

• Sumitomo Rubber Ind

Inventors

• Nonaka Kenji

Classifications

• B60C9/023 Primary

  built up from narrow strips, individual cords or filaments, e.g. using filament winding · CPC title

• B60C9/0238

  characterised by special physical properties of the carcass ply · CPC title

• B60C2009/0276

  Modulus; Hardness; Loss modulus or "tangens delta" · CPC title

• B60C2200/10

  for motorcycles, scooters or the like · CPC title

• B60C9/06 Primary

  the cords extend diagonally from bead to bead and run in opposite directions in each successive carcass ply, i.e. bias angle ply (B60C9/07, B60C9/09 take precedence) · CPC title