Motorcycle tires

Abstract

A motorcycle tire comprising a radial carcass structure (2) and a tread band (8) applied in a radially outer position with respect to the radial carcass structure (2), the radial carcass structure (2) comprising a first carcass ply (3a) and a second carcass ply (3b) each including a first plurality of textile reinforcement cords (30) and a second plurality of textile reinforcement cords (32), the first textile reinforcement cords (31) being parallel to each other and the second textile reinforcement cords (33) being parallel to each other, the first textile reinforcement cords (31) and the second textile reinforcement cords (33) having first and second inclinations, respectively, with respect to an equatorial plane (XX) of the tire in a crown portion (8c) of the tread band (8), the second inclination being in a direction opposite to the first inclination. The first plurality of textile reinforcing cords (31) and the second plurality of textile reinforcing cords (33) have a tensile strength at 2% elongation comprised between 0.35 cN / Tex and 1.2 cN / Tex and at 5% elongation comprised between 0.5 cN / Tex and 3 cN / Tex. At least one central annular sector (8a) of the tread band (8) arranged astride the equatorial plane (XX) is made of a vulcanized elastomeric material having a static modulus of elasticity Ca3 measured at 70°C comprised between 9.0 and 14.0, a tan delta measured at 70°C and 10 Hz comprised between 0.120 and 0.160, and a dynamic modulus of elasticity E' measured at 70°C and 10 Hz comprised between 3.7 and 4.1.

Description

Technical Field

[0001] The present invention relates to a motorcycle tire.

[0002] The tire of the present invention is intended to be mounted on the front wheel and / or rear wheel of a "big enduro" (or "big adventure touring" or "dual purpose") motorcycle. As is known, these motorcycles are motorcycles with large displacement, high power output, and high mass designed to travel on both tarmac roads and off-road. Such motorcycles generally have a piston displacement of 1000 cm 3 or more, an output of 100 cv or more, a maximum torque of 100 Nm or more, and a mass of 180 kg or more.

[0003] Examples of "big enduro" motorcycles include BMW® R 1250 GS, KTM 1290 Super Adventure R, and Honda® CRF1100L Africa Twin.

[0004] This type of motorcycle has a very wide range of uses, from use mainly on public roads, comparable to sport touring which also extends to super sports, to use on more extreme off-road conditions than simple paved roads, such as traveling on all-terrain circuits, so-called dirt tracks, or tracks including riverbeds, soft ground, mud, sand, and uneven terrain of various types and difficulty levels.

[0005] In order to satisfy all these types of use, the market provides different tire products each focused on clearly defined types of use, for example, sport driving on public roads, touring driving on public roads, driving on public roads combined with unpaved roads, driving on public roads combined with mild off-road, and extreme off-road driving combined with public roads.

[0006] Typically, "big enduro" motorcycle tires, primarily intended for riding on public roads combined with unpaved sections, are permitted for speeds up to at least 210 km / h (ETRTO speed rating: H). Such tires generally have a maximum radial section width ranging from 90 to 170 (e.g., 90 to 120 for front tires and 130 to 170 for rear tires) and are mounted on wheel rims with a mounting diameter ranging from approximately 17 to 21 inches (e.g., 19 to 21 inches for front tires and 17 to 18 inches for rear tires).

[0007] The tires of the present invention are of a type approved for use on public roads, and are intended for use on public roads, primarily in combination with unpaved roads, and are typically intended for use on public roads under different load conditions (driver only, driver and luggage, driver and one passenger, driver, one passenger and luggage), and different weather conditions, as well as for use on unpaved roads to a minimum extent. [Background technology]

[0008] "Big Enduro" motorcycle tires typically feature a tread band with a tread pattern defined by circumferential and transverse grooves that at least partially separate each portion of the tread or tread blocks. Such tires typically have an air-to-solid ratio ranging from approximately 0.1 to approximately 0.65. [Overview of the Initiative]

[0009] In this specification and the following claims, all numerical values ​​representing quantities, parameters, percentages, etc., shall be deemed to be preceded in all cases by the term “approximately” unless otherwise specified. Furthermore, all ranges of magnitude of numbers include all possible combinations of the largest and smallest values, all possible intermediate ranges, and those specifically shown below.

[0010] Unless otherwise specified, all ranges of quantities include the maximum and minimum values.

[0011] The following definitions apply:

[0012] The term "phr" (an acronym for parts per hundred parts of rubber) refers to the parts by weight of a given elastomer compound component per 100 parts by weight of an elastomeric polymer, taking into account the net amount of plasticizer.

[0013] The terms “elastomer material,” “rubber,” “elastomerous polymer,” or “elastomer” are used to describe materials comprising vulcanizable natural or synthetic polymers and reinforcing fillers, which, at room temperature, can be deformed by force after vulcanization and, after the deformable force is removed, can quickly and forcefully return to substantially their original shape and size (according to the standard ASTM D1566-11 Definitions of Standard Terms relating to Rubber).

[0014] The term "diene polymer" means a polymer or copolymer derived from the polymerization of one or more different monomers, of which at least one is a conjugated diene (conjugated diolefin).

[0015] The term "elastomer compound" is intended to refer to a mixture that can be obtained by mixing at least one elastomeric polymer with at least one additive commonly used in the preparation of tire compounds, and optionally by heating.

[0016] The term "vulcanizable elastomer compound" refers to a vulcanization-ready elastomer mixture that can be obtained by incorporating all additives, including vulcanization additives, into an elastomer compound.

[0017] The term "vulcanizable elastomer compound" refers to a material that can be obtained by vulcanization of a vulcanizable elastomer compound.

[0018] The term "vulcanization" typically refers to a crosslinking reaction in natural or synthetic rubber induced by a sulfur-based crosslinking agent.

[0019] The term "vulcanizing agent" refers to a compound that can transform natural or synthetic rubber into an elastic and strong material by forming a three-dimensional network of intermolecular and intramolecular bonds. Typical vulcanizing agents include elemental sulfur, polymeric sulfur, and sulfur donors, such as sulfur compounds like bis[(trialkoxysilyl)propyl]polysulfide, thiuram, dithiodimorpholine, and caprolactam disulfide.

[0020] The term "vulcanization accelerator" refers to compounds that can reduce the duration and / or operating temperature of the vulcanization process, such as TBBS, generally sulfenamides, thiazoles, dithiophosphates, dithiocarbamates, and guanidines, as well as sulfur donors such as thiuram.

[0021] The term "vulcanization activator" refers to a compound that can further accelerate vulcanization by causing it to occur in a shorter time and, in some cases, at a lower temperature. An example of an activator is the stearic acid-zinc oxide system.

[0022] The term "vulcanization inhibitor" refers to a compound that can delay the initiation of a vulcanization reaction and / or suppress undesirable secondary reactions, such as N-(cyclohexylthio)phthalimide (CTP).

[0023] The term "vulcanization package" means a vulcanizing agent and one or more vulcanization additives selected from vulcanization activators, accelerators, and inhibitors.

[0024] The term "reinforcing filler" is meant to denote reinforcing materials typically used in the industry for improving the mechanical properties of tires, preferably selected from carbon black, conventional silica such as sand-derived silica precipitated with a strong acid, preferably amorphous, diatomaceous earth, calcium carbonate, titanium dioxide, talc, alumina, aluminosilicate, kaolin, silicate fibers, and mixtures thereof.

[0025] The term "white filler" is meant to denote conventional reinforcing materials used in the industry, selected from silica, optionally modified by acid treatment and / or derivatization, and conventional silicates, for example, palygorskite (also known as sepiolite, attapulgite), montmorillonite, halloysite, and the like. Typically, white fillers have surface hydroxyl groups.

[0026] The expression "reinforcement cord", or more simply "cord", is meant to denote an elongated element consisting of one or more elongated elements (also called "yarns"), optionally coated with or incorporated into a matrix of an elastomer material.

[0027] Hereinafter, the expression "yarn" is used to refer to an elongated element formed of an aggregate of a plurality of textile filaments.

[0028] Each filament can also be referred to as a "fiber".

[0029] The term "linear density" or "count" of a cord or yarn or plurality of filaments is meant to denote the weight of the cord or yarn or plurality of filaments per unit length. Linear density can be measured in dtex (grams per 10 km of length).

[0030] A yarn can have one or more “ends,” and the term “end” refers to a bundle of filaments twisted together. For example, there may be a single end or at least two ends twisted together.

[0031] Yarn can be identified by a symbol representing the textile material, the fiber count used, and the number of ends that form the yarn. For example, a yarn with ends made of NY (nylon), identified as NY 1400×2, indicates a yarn containing 1400 dtex count NY fibers formed from two ends twisted together.

[0032] The term "thread count" for a layer, ply, or fabric refers to the number of reinforcing cords per unit length present in such a layer / ply / fabric. Thread count can be measured in cords per decimeter or TPI (threads per inch).

[0033] The terms “breaking load” and “breaking elongation” for reinforcing cords or yarns refer to the load and percentage elongation, respectively, at which the reinforcing cord or yarn breaks, as evaluated according to the BISFA standard for materials tested according to the definitions shown below.

[0034] The term "modulus of elasticity" refers to the ratio of load (or force) to elongation measured at any point on the load-elongation curve according to the BISFA standard, for materials tested according to the definition shown below. Such a curve is drawn by calculating the first derivative of the load-elongation function that defines the aforementioned curve, normalized to the linear density expressed in Tex. Thus, the modulus of elasticity is expressed in cN / Tex or Mpa. In the load-elongation graph, the modulus of elasticity is determined by the slope of the aforementioned curve with respect to the x-axis.

[0035] The term "tensile strength (tenacity)" of a reinforcing cord or yarn refers to the calculated ratio between the modulus of elasticity and the linear density. Tensile strength was measured according to BISFA standards for materials tested according to the definitions shown below. Tensile strength can be expressed in cN / Tex or cN / dTex.

[0036] For the purposes of this invention, we refer to flat threads that have not been further aligned during the testing phase, according to the tests specified by the BISFA (Bureau International pour la Standardisation des Fibres Artificielles) standard, for the purpose of measuring linear density and determining tensile properties, particularly tensile strength. In particular, - For nylon (NY), see BISFA - Test Methods for Polyamide Yarn - 2004 Edition: • Determination of Linear Density - Chapter 6 - Procedure A; • Determination of tensile properties - Chapter 7 - Procedure A; • Preparation of research samples: Preparation of samples in a relaxed state - Paragraph 7.4.1.1 => Preparation of samples on a folding reel; • Preparation and test performance of laboratory samples: Manual testing - Paragraph 7.5.2.1 => c); • Starting procedure => e) Pretension at the start of the procedure; • Tension measurements performed with a Zwick-Roell Z010 dynamometer See below. - For cellulose material cords or reinforcing wires, e.g., rayon (Ry) or lyocell (LY), see BISFA - Test Methods for Viscose, Cupro, Acetate, Triacetate and Lyocell Fiber Yarns - 2007 Edition • Determination of tensile properties: Chapter 7 - Tensile test conditions: Oven drying test - Table 7.1 - Test procedure - Section 7.5 - Test on samples in oven relaxation state - Section 7.5.2.4 See below.

[0037] The term "motorcycle tire" refers to a tire that has a large curvature ratio (typically greater than 0.20) and is capable of achieving a large camber angle when cornering.

[0038] The term "curvature ratio" refers to the ratio of the distance (also indicated by an "arrow") between the radially highest point of the tread band and the maximum radial width of the tire's cross-section, to the aforementioned maximum width of the tire.

[0039] The term "axial extension" of the tread band or a portion thereof refers to the extension of the radially outermost profile of the tread band or a portion thereof in a tire cross-section taken to pass through the plane containing the tire's axis of rotation.

[0040] The term "equator plane" of a tire refers to a plane that is perpendicular to the tire's axis of rotation and symmetrically bisects the tire.

[0041] The term "width" refers to a dimension measured along a direction perpendicular to the equatorial plane.

[0042] The term "annular sector" refers to a portion of the tread band with a predetermined axial length that extends circumferentially across the entire tread band.

[0043] The term "tread pattern" refers to all parts of the tread band (including grooves) in a plane perpendicular to the tire's equatorial plane and tangent to the tire's maximum diameter. The tread pattern is defined by multiple blocks, separated by grooves, and sometimes including recesses.

[0044] The term "void / solid ratio" refers to the ratio of the total surface area of ​​the grooves in a particular annular portion of the tire's tread pattern (sometimes the entire tread band or the entire tread pattern) to the surface area of ​​a particular portion of the tread pattern (sometimes the entire tread band or the entire tread pattern).

[0045] The term "footprint" of a tire refers to the portion of the tire that comes into contact with the ground or road surface when the tire is mounted on the wheel rim and a predetermined vertical load is applied to the tire.

[0046] The terms “radial” and “axial,” as well as the expressions “radially inward / outward” and “axially inward / outward,” are used to refer to the direction substantially parallel to the equatorial plane of the tire and the direction substantially perpendicular to the equatorial plane of the tire, respectively; that is, the direction substantially perpendicular to the turning axis of the tire and the direction substantially parallel to the turning axis of the tire, respectively.

[0047] The terms "circumferential" and "circumferential" are used to refer to the direction that extends circumferentially around the tire, i.e., the direction in which the tire rolls, and correspond to a direction on a plane that coincides with or is substantially parallel to the tire's equatorial plane.

[0048] The term "circumferential extension" of a tire, tread band, or any part thereof is used to refer to the extension in plan of the radially outermost surface of the tire, tread band, or any part thereof, on the plane in contact with the tire.

[0049] The terms "axially inward" and "axially outward" indicate the position of the reference element that is close to the equatorial plane and the position that is farther from the equatorial plane, respectively.

[0050] The term “radial carcass structure” refers to a carcass structure in which multiple reinforcing cords, each substantially oriented along the axial direction, are present in the crown portion of the tire. Such reinforcing cords can be incorporated into a single carcass ply or into multiple carcass plies (preferably two) juxtaposed radially to one another.

[0051] The term "effectively axial" refers to a direction inclined at an angle between 60° and 90° relative to the tire's equatorial plane.

[0052] The term "substantially circumferential" is used to indicate a direction that is oriented at an angle between 0° and 20° relative to the tire's equatorial plane.

[0053] The term "static mechanical properties" of a tread compound refers to the tensile stress-strain properties of a vulcanized thermoplastic rubber according to the UNI 6065:2001 standard, measured at a predetermined temperature on a sample of the compound vulcanized at 170°C for 10 minutes. For example, the static modulus of elasticity CA3 at 70°C represents the load at 300% elongation measured at 70°C.

[0054] The term "dynamic mechanical properties" of the tread compound refers to the mechanical properties measured using an Instron Model 1341 dynamic device in tension-compression mode, as described here. A cylindrical specimen of the crosslinked material (length = 25 mm; diameter = 18 mm) was used (15 minutes at 170°C), preloaded under compression up to 25% longitudinal deformation with respect to the initial length, and maintained at predetermined temperatures (e.g., 23°C, 70°C, and 100°C) throughout the test period. After a 2-minute waiting period following 125 cycles of mechanical adjustment at 10 Hz with an amplitude of 7.5% deformation relative to the length under the preload, the specimen was subjected to a dynamic sinusoidal stress at a frequency of 10 Hz under the preload, with an amplitude of ±3.5% relative to the length. Dynamic mechanical properties are expressed in terms of the values ​​of the dynamic modulus (E') and tandelta (loss factor). The tandelta value was calculated as the ratio of the viscous dynamic modulus (E'') to the dynamic modulus (E').

[0055] The applicant recognizes that, in order to optimally cover its entire range of use, a "big enduro" motorcycle must be equipped with tires that are capable of traveling many kilometers and are suitable for enabling high performance on both public roads (primarily high-speed stability, road holding in dry and wet conditions, and handling) and off-road (primarily traction, controllability, and directional stability).

[0056] However, the applicant found that, according to the current and increasingly common trend of seeking extreme performance on public roads on the one hand and extreme performance off-road on the other, the aforementioned performance characteristics are at least partially contrasting with each other.

[0057] The applicant has observed that tires capable of high performance on public roads are typically severely limited in their off-road performance, and vice versa.

[0058] The applicant also noted that tires that strike a good compromise between use on public roads and off-road cannot achieve satisfactory extreme performance in either of the two environments (public roads or off-road).

[0059] The applicant has recently noticed that the market is anticipating many segments of tires for “big enduro” motorcycles, and that each of these segments is moving towards more specialized solutions that match customer demands by focusing on specific applications of motorcycles.

[0060] Therefore, the applicant proposes a “big enduro” motorcycle tire intended for use primarily on public roads, i.e., for use primarily on public roads under different load conditions (driver only, driver and luggage, driver and one passenger, driver, one passenger and luggage), and different weather conditions, as well as for use on public roads combined with unpaved roads, providing minimal use on unpaved roads.

[0061] Tires primarily designed for use on public roads are engineered to maximize performance on tarmac surfaces, including high-speed stability under varying load conditions, road holding in dry and wet conditions, handling, fuel efficiency, and traction and braking in wet conditions.

[0062] The applicant is focusing on the aforementioned segment-type tires for "big enduro" motorcycles, which are designed primarily for on-road use and are expected to be chosen by users who require performance on public roads under various load conditions and do not demand much from off-road use.

[0063] The applicant envisioned creating a "big enduro" motorcycle tire primarily for use on public roads, which would improve performance in terms of high-speed stability under different load conditions (driver only, driver and luggage, driver and one passenger, driver, one passenger and luggage) on tarmac surfaces.

[0064] Motorcycle tires typically consist of a radial carcass structure extending between a bead structure on both sides and a zero-degree reinforcing layer optionally positioned radially outward relative to the carcass structure, or comprising such a zero-degree reinforcing layer, and a belt structure positioned radially outward relative to the carcass structure, as well as a tread band positioned radially outward relative to the belt structure.

[0065] The carcass structure is intended to impart the desired properties of integrity and structural strength to the tire, and the belt structure, which contributes to obtaining the aforementioned properties of integrity and structural strength, is intended to transmit the lateral and longitudinal stresses acting on the tire during travel after contact with the road surface to the carcass structure. If present, the zero-degree reinforcing layer is intended to limit the radial deformation of the belt structure.

[0066] The handling characteristics of a motorcycle as perceived by the driver, and therefore the high-speed stability and handling performance in both dry and wet conditions, depend on the motorcycle's grip under all riding conditions and are therefore related to its footprint area. The stability of the footprint area, i.e., its ability to remain as constant as possible, is conferred by the stiffness of the tire. Within certain limits, the stiffer the tire, the less it deforms, and the faster it recovers from deformation under stress.

[0067] Therefore, the applicant considered using increased stiffness in tires primarily for "big enduro" motorcycles used on public roads to improve their performance in terms of high-speed stability under different load conditions.

[0068] To increase the rigidity of the tire, the applicant considered increasing the rigidity of the carcass structure.

[0069] Multiple reinforcing cords are typically incorporated into the carcass structure to impart structural strength and rigidity to the carcass structure.

[0070] Typically, reinforcing cords made from low modulus textile yarns are used to enhance ride comfort at the expense of performance in terms of stability, directional stability, and controllability.

[0071] On the other hand, reinforcing cords made from high modulus textile yarn are used to enhance absolute performance in terms of ride stability, control, directional stability, and road holding during sudden changes in direction and / or speed, at the expense of ride comfort.

[0072] The applicant has found that by creating a carcass structure using high modulus textile yarn, the rigidity of tires for "big enduro" motorcycles is increased, improving performance in terms of high-speed stability under different load conditions.

[0073] However, the applicant noted that this improvement in high-speed stability under different load conditions was accompanied by a deterioration in handling on both dry and wet surfaces.

[0074] To restore handling on both dry and wet surfaces, the applicant considered using so-called soft compounds that better adapt to road surface roughness by transferring their irregular profile to form tread bands. These compounds typically feature low static mechanical properties and high hysteresis properties (with respect to dynamic mechanical properties under compression, particularly with respect to tandelta).

[0075] The applicant found that using a soft compound in the tread band actually increases handling on both dry and wet surfaces.

[0076] However, the applicant has noticed that the use of soft compounds in the tread band reduces stability at high speeds, particularly under heavy loads, i.e., when there are passengers and / or luggage in addition to the driver, during straight-line driving.

[0077] The applicant has found that, surprisingly, by arranging a radial carcass structure with two juxtaposed carcass plies with reinforcing cords made from low modulus textile yarn, and by arranging at least one annular sector positioned across the equatorial plane with a tread band made of a compound having high static mechanical properties and low hysteresis, it is possible to create a tire for "big enduro" motorcycles, primarily for use on public roads, that improves, in fact surprisingly, the handling performance in dry and wet conditions without deterioration, and improves the performance in terms of high-speed stability under various load conditions.

[0078] The radial carcass structure, with reinforcing cords made from low modulus textile yarn and tread bands having at least one annular sector positioned across the equatorial plane, made from compounds with high static mechanical properties and low hysteresis, does not appear suitable for simultaneously providing high-speed stability under different load conditions, as well as handling in both dry and wet conditions. Therefore, the improvement in the tire's high-speed stability and handling performance in both dry and wet conditions is remarkable.

[0079] The present invention relates to a motorcycle tire comprising a radial carcass structure and a tread band applied to the radially outer position relative to the radial carcass structure.

[0080] Preferably, the radial carcass structure comprises a first carcass ply including a first plurality of textile reinforcing cords.

[0081] Preferably, the carcass structure comprises a second carcass ply including a second plurality of textile reinforcing cords.

[0082] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords are substantially parallel to each other in the crown portion of the tread band and have a first inclination of a predetermined angle with respect to the equatorial plane of the tire.

[0083] Preferably, the textile reinforcing cords of the second plurality of textile reinforcing cords are substantially parallel to each other in the crown portion of the tread band and have a second inclination of a predetermined angle with respect to the equatorial plane of the tire.

[0084] Preferably, the second inclination is in the opposite direction to the first inclination.

[0085] Preferably, the second carcass ply is radially juxtaposed on the first carcass ply.

[0086] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.35 cN / Tex at 2% elongation.

[0087] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength of less than 1.2 cN / Tex at 2% elongation.

[0088] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.5 cN / Tex at 5% elongation.

[0089] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength of less than 3.0 cN / Tex at a 5% elongation.

[0090] Preferably, at least one central annular sector of the tread band, which is positioned across the equatorial plane, is made of a vulcanized elastomer material whose static modulus of elasticity Ca3, measured at 70°C, is greater than 9.0.

[0091] Preferably, at least one central annular sector of the tread band, which is positioned across the equatorial plane, is made of a vulcanized elastomer material with a static modulus of elasticity Ca3 less than 14.0 as measured at 70°C.

[0092] More preferably, the central annular sector is made of a vulcanized elastomer material whose static elastic modulus Ca3 measured at 70°C is greater than 10.0.

[0093] More preferably, the central annular sector is made of a vulcanized elastomer material with a static elastic modulus Ca3 less than 13.0, as measured at 70°C.

[0094] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta greater than 0.120, as measured at 70°C and 10Hz.

[0095] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta less than 0.160, measured at 70°C and 10Hz.

[0096] More preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta greater than 0.135, as measured at 70°C and 10Hz.

[0097] More preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta less than 0.155 as measured at 70°C and 10Hz.

[0098] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is greater than 3.7.

[0099] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is less than 4.1.

[0100] The applicant has experimentally discovered that, surprisingly, by using a cross-ply carcass structure and tread band having the aforementioned characteristics, it is possible to improve the handling performance in dry and wet conditions of "big enduro" type motorcycle tires, which are primarily intended for on-road use and do not require much for off-road use, and to actually improve their high-speed stability under different load conditions, without degrading their handling performance.

[0101] Without being bound by any interpretive theory, the applicant believes that the unexpected improvements in high-speed stability and handling in dry and wet conditions can be attributable, at least in part, to the improvement in tire stiffness and, consequently, high-speed stability under different load conditions, by creating a radial carcass-ply structure having two radially juxtaposed plies, and by controlling the static modulus of elasticity Ca3 at 70°C of the central annular sector of the tread band positioned across the equatorial plane to within the aforementioned value, as well as to the improvement in handling in dry and wet conditions in such a structure by controlling the tensile strength of the textile reinforcing cords of the carcass ply to within the aforementioned value, and by controlling the tan delta at 70°C and the dynamic modulus of elasticity E' at 70°C to within the aforementioned value.

[0102] Surprisingly, this beneficial technical effect was also observed by using relatively "low" tensile strength textile reinforcing cords in the carcass ply, which are known not to be used to make the tire stiffer, as well as a relatively "low" tandelta value at 70°C (and therefore limited hysteresis), which are known not to be beneficial in improving handling in dry and wet conditions.

[0103] The present invention can present at least one of the preferred characteristics described below.

[0104] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.4 cN at a 2% elongation.

[0105] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.45 cN / Tex at 2% elongation.

[0106] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.5 cN / Tex at a 2% elongation.

[0107] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.55 cN / Tex at 2% elongation.

[0108] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 1.0 cN / Tex at 2% elongation.

[0109] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 0.85 cN / Tex at 2% elongation.

[0110] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 0.7 cN / Tex at 2% elongation.

[0111] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 0.6 cN / Tex at 2% elongation.

[0112] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 0.57 cN / Tex at 2% elongation.

[0113] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.6 cN / Tex at 5% elongation.

[0114] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.7 cN / Tex at 5% elongation.

[0115] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.8 cN / Tex at 5% elongation.

[0116] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.85 cN / Tex at 5% elongation.

[0117] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.9 cN / Tex at 5% elongation.

[0118] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength greater than 0.95 cN / Tex at 5% elongation.

[0119] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 2.5 cN / Tex at 5% elongation.

[0120] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 2 cN / Tex at 5% elongation.

[0121] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 1.5 cN / Tex at 5% elongation.

[0122] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 1.2 cN / Tex at 5% elongation.

[0123] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 1.1 cN / Tex at 5% elongation.

[0124] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a tensile strength less than 1 cN / Tex at 5% elongation.

[0125] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 greater than 10.8, as measured at 70°C.

[0126] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material whose static elastic modulus Ca3, measured at 70°C, is greater than 11.

[0127] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 greater than 11.3, as measured at 70°C.

[0128] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 less than 12.5, as measured at 70°C.

[0129] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 less than 12, as measured at 70°C.

[0130] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 less than 11.8, as measured at 70°C.

[0131] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material with a static elastic modulus Ca3 less than 11.7, as measured at 70°C.

[0132] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material having a static elastic modulus Ca3 of 11.5 as measured at 70°C.

[0133] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta greater than 0.140, as measured at 70°C and 10Hz.

[0134] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta greater than 0.142, as measured at 70°C and 10Hz.

[0135] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta less than 0.150, measured at 70°C and 10Hz.

[0136] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta less than 0.148, measured at 70°C and 10Hz.

[0137] Preferably, the central annular sector is made of a vulcanized elastomer material with a tandelta of 0.145 as measured at 70°C and 10Hz.

[0138] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is greater than 3.8.

[0139] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is less than 4.

[0140] Preferably, the central annular sector is made of a vulcanized elastomer material having a dynamic modulus of elasticity E' of 3.9 as measured at 70°C and 10Hz.

[0141] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material in which the ratio of the tandelta measured at 70°C and 10Hz to the dynamic modulus of elasticity E' measured at 70°C and 10Hz is greater than 0.03.

[0142] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material in which the ratio of the tandelta measured at 70°C and 10Hz to the dynamic modulus of elasticity E' measured at 70°C and 10Hz is greater than 0.035.

[0143] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material in which the ratio of the tandelta measured at 70°C and 10Hz to the dynamic modulus of elasticity E' measured at 70°C and 10Hz is less than 0.04.

[0144] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material in which the ratio of the tandelta measured at 70°C and 10Hz to the dynamic modulus of elasticity E' measured at 70°C and 10Hz is less than 0.038.

[0145] Preferably, the central annular sector of the tread band is made of a vulcanized elastomer material having a ratio of 0.037 between the tandelta measured at 70°C and 10Hz and the dynamic modulus of elasticity E' measured at 70°C and 10Hz.

[0146] Preferably, the tread band is positioned on both sides of the tire's equatorial plane and comprises two lateral annular sectors adjacent to the central annular sector.

[0147] Preferably, the central annular sector is made of a different elastomer material than the elastomer material from which the two lateral annular sectors are made.

[0148] Preferably, the central annular sector is made of a vulcanized elastomer material having a tandelta measured at 70°C and 10Hz that is smaller than the tandelta measured at 70°C and 10Hz of the vulcanized elastomer material of the two lateral annular sectors.

[0149] This allows for compounds with higher hysteresis in the shoulders, i.e., the two lateral annular sectors, compared to the crown compound, i.e., the central annular sector, enabling the tire to better adapt to road surface roughness by transferring its irregular profile during cornering.

[0150] The applicant has noted that higher hysteresis in the two lateral annular sectors compared to the central sector does not affect high-speed stability under different load conditions.

[0151] Preferably, the central annular sector is made of a vulcanized elastomer material whose tan delta, measured at 70°C and 10Hz, is greater than a threshold, the threshold being equal to 75% of the tan delta of the vulcanized elastomer material of the lateral annular sectors, measured at 70°C and 10Hz.

[0152] Preferably, the central annular sector is made of a vulcanized elastomer material whose tan delta, measured at 70°C and 10Hz, is greater than a threshold, which is equal to 80% of the tan delta of the vulcanized elastomer material of the lateral annular sector, measured at 70°C and 10Hz.

[0153] Preferably, the central annular sector is made of a vulcanized elastomer material whose tan delta, measured at 70°C and 10Hz, is greater than a threshold, the threshold being equal to 85% of the tan delta of the vulcanized elastomer material of the lateral annular sectors, measured at 70°C and 10Hz.

[0154] Preferably, the central annular sector is made of a vulcanized elastomer material whose tan delta, measured at 70°C and 10Hz, is greater than a threshold, the threshold being equal to 90% of the tan delta of the vulcanized elastomer material of the lateral annular sectors, measured at 70°C and 10Hz.

[0155] Preferably, the central annular sector is made of a vulcanized elastomer material whose tandelta, measured at 70°C and 10Hz, is less than a threshold, which is equal to 98% of the tandelta of the vulcanized elastomer material of the lateral annular sectors, measured at 70°C and 10Hz.

[0156] Preferably, the central annular sector is made of a vulcanized elastomer material whose tandelta, measured at 70°C and 10Hz, is less than a threshold, which is equal to 95% of the tandelta of the vulcanized elastomer material of the lateral annular sectors, measured at 70°C and 10Hz.

[0157] Preferably, the central annular sector is made of a vulcanized elastomer material in which the tandelta measured at 70°C and 10Hz is equal to 92% of the tandelta of the vulcanized elastomer material of the lateral annular sector measured at 70°C and 10Hz.

[0158] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E', measured at 70°C and 10Hz, is greater than the dynamic modulus E', measured at 70°C and 10Hz, of the two lateral annular sector vulcanized elastomer materials.

[0159] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, where the threshold is equal to 115% of the dynamic modulus E' of the vulcanized elastomer material of the two lateral annular sectors measured at 70°C and 10Hz.

[0160] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, the threshold being equal to 112% of the dynamic modulus E' of the vulcanized elastomer material of the two lateral annular sectors measured at 70°C and 10Hz.

[0161] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, the threshold being equal to 109% of the dynamic modulus E' of the vulcanized elastomer material of the two lateral annular sectors measured at 70°C and 10Hz.

[0162] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is greater than a threshold, the threshold being equal to 101% of the dynamic modulus E' of the vulcanized elastomer material of the two lateral annular sectors measured at 70°C and 10Hz.

[0163] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E' measured at 70°C and 10Hz is greater than a threshold, the threshold being equal to 103% of the dynamic modulus E' of the vulcanized elastomer material of the two lateral annular sectors measured at 70°C and 10Hz.

[0164] Preferably, the central annular sector is made of a vulcanized elastomer material whose dynamic modulus E', measured at 70°C and 10Hz, is equal to 106% of the dynamic modulus E' of the two lateral annular sector vulcanized elastomer materials, measured at 70°C and 10Hz.

[0165] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is smaller than the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz for the two lateral annular sector vulcanized elastomer materials.

[0166] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is greater than a threshold, the threshold being equal to 75% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0167] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is greater than a threshold, the threshold being equal to 80% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0168] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is greater than a threshold, the threshold being equal to 85% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0169] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, the threshold being equal to 98% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0170] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, the threshold being equal to 95% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0171] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is less than a threshold, the threshold being equal to 90% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz of the two lateral annular sector vulcanized elastomer materials.

[0172] Preferably, the central annular sector is made of a vulcanized elastomer material in which the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is equal to 87% of the ratio of the tan delta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz for the two lateral annular sector vulcanized elastomer materials.

[0173] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus Ca3, measured at 70°C, is greater than the static modulus Ca3, measured at 70°C, of ​​the vulcanized elastomer material of the two lateral annular sectors.

[0174] This makes it possible to have compounds with lower static mechanical performance in the lateral annular sector compared to compounds in the central annular sector, which contributes to the tire better adapting to road surface roughness by transferring its irregular profile during cornering.

[0175] The applicant has noticed that the static modulus of the lateral annular sector, particularly Ca3, measured at 70°C, is not equal to the value of the static modulus of the central annular sector, and that it is possible to obtain high-speed stability under different load conditions solely by increasing the static modulus of the compound in the central annular sector.

[0176] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is less than a threshold, the threshold being equal to 150% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0177] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is less than a threshold, the threshold being equal to 140% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0178] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is less than a threshold, the threshold being equal to 135% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0179] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is greater than a threshold, the threshold being equal to 101% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0180] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is greater than a threshold, the threshold being equal to 110% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0181] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is greater than a threshold, the threshold being equal to 120% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0182] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus of elasticity Ca3 measured at 70°C is greater than a threshold, the threshold being equal to 125% of the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors.

[0183] Preferably, the central annular sector is made of a vulcanized elastomer material whose static modulus Ca3, measured at 70°C, is equal to 130% of the static modulus Ca3 of the vulcanized elastomer material of the two lateral annular sectors, measured at 70°C.

[0184] Preferably, the central annular sector has an axial extension with a width greater than 15% of the width of the tread band.

[0185] Preferably, the central annular sector has an axial extension with a width greater than 18% of the width of the tread band.

[0186] Preferably, the central annular sector has an axial extension with a width less than 30% of the width of the tread band.

[0187] Preferably, the central annular sector has an axial extension with a width less than 28% of the width of the tread band.

[0188] Preferably, the central annular sector has an axial extension with a width equal to 22% of the width of the tread band.

[0189] Preferably, the two lateral annular sectors each have an axial extension of equal width.

[0190] Preferably, the sum of the widths of the axial extensions of the two lateral annular sectors and the axial extension of the central annular sector matches the width of the axial extension of the tread band.

[0191] Preferably, the tread band has a void / solid ratio contained in 0.4 to 0.65.

[0192] Preferably, the tread band has a tread pattern that is symmetrical with respect to the equatorial plane of the tire.

[0193] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords are made of the same material.

[0194] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords are made of fibers selected from the group including aliphatic polyamide fibers (e.g., nylon 6, nylon 6.6, nylon 4.6, nylon 4.10, nylon 10.10, nylon 11, nylon 12, nylon 6.10, nylon 6.12), polyester fibers (e.g., polyethylene terephthalate), and rayon fibers.

[0195] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords are made of nylon.

[0196] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords are made of nylon 6.6.

[0197] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have equal linear density.

[0198] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density greater than 2000.

[0199] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density greater than 2200.

[0200] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density greater than 2400.

[0201] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density greater than 2600.

[0202] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density less than 4600.

[0203] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density less than 4200.

[0204] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density less than 3800.

[0205] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density less than 3200.

[0206] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density less than 3000.

[0207] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a linear density of 2800 dTex.

[0208] Preferably, the textile reinforcing cords of the first and second plurality of textile reinforcing cords have a line density greater than 1100 × 2dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0209] Preferably, the textile reinforcing cords of the first and second plurality of textile reinforcing cords have a line density greater than 1200 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0210] Preferably, the textile reinforcing cords of the first and second sets of textile reinforcing cords have a linear density less than 1840 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0211] Preferably, the textile reinforcing cords of the first and second plurality of textile reinforcing cords have a line density less than 1600 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0212] Preferably, the textile reinforcing cords of the first and second plurality of textile reinforcing cords have a linear density less than 1400 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0213] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have the same thread count.

[0214] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count greater than 80 cords / dm.

[0215] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count greater than 90 cords / dm.

[0216] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count greater than 100 cords / dm.

[0217] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count less than 130 cords / dm.

[0218] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count less than 125 cords / dm.

[0219] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count less than 120 cords / dm.

[0220] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count of 112 cords / dm.

[0221] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have equal twists applied to each end and to the entirety of the ends that form the textile reinforcing cord.

[0222] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist applied to each end and the entirety of the ends forming the textile reinforcing cord, with more than 30 twists per decimeter.

[0223] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist applied to each end and the entirety of the ends forming the textile reinforcing cord, with a twist of more than 35 times per decimeter.

[0224] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist applied to each end and the entirety of the ends forming the textile reinforcing cord, with a twist of more than 38 twists per decimeter.

[0225] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist imparted to each end and the entirety of the ends forming the textile reinforcing cord, with fewer than 65 twists per decimeter.

[0226] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist imparted to each end and the entirety of the ends forming the textile reinforcing cord, with fewer than 55 twists per decimeter.

[0227] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist imparted to each end and the entirety of the ends forming the textile reinforcing cord, with fewer than 45 twists per decimeter.

[0228] Preferably, the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a twist applied to each end and the entirety of the ends forming the textile reinforcing cord, forming 40 twists per decimeter.

[0229] Preferably, the predetermined inclination angle of the textile reinforcing cords of the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords is in the range of 65° to 90° in the crown portion of the tread band, more preferably in the range of 65° to 75°, for example, 70°.

[0230] Preferably, the first carcass ply and the second carcass ply consist of sheets of elastomer material incorporating the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords, respectively.

[0231] Preferably, the belt structure is located radially outward relative to the radial carcass structure and radially inward relative to the tread band.

[0232] Preferably, the belt structure comprises a belt layer having at least one reinforcing cord that forms a plurality of windings substantially in the direction of the circumferential direction of the tire.

[0233] Preferably, the belt layer comprises a rubberized fabric reinforcing ribbon-like element that includes a plurality of axially aligned reinforcing cords forming a plurality of windings substantially in the direction of the circumferential direction of the tire.

[0234] Preferably, the multiple windings are angled within 0° to 5° with respect to the equatorial plane of the tire.

[0235] Preferably, at least one reinforcing cord is made of a metallic material.

[0236] Preferably, at least one reinforcing cord is made of high-carbon steel, with a carbon content of at least 0.6% by weight.

[0237] Preferably, the carcass reinforcement structure is made of an elastomer material radially positioned between the radial carcass structure and the belt structure.

[0238] Preferably, the carcass reinforcement structure made of elastomer material extends axially over a surface substantially corresponding to the surface of the extension of the belt structure.

[0239] Further characteristics and advantages of the tire of the present invention will become more apparent from the following detailed description of its preferred embodiments, made with reference to the accompanying drawings. [Brief explanation of the drawing]

[0240] [Figure 1] This is a schematic perspective view of the radial cross-section of a motorcycle tire according to the present invention. For the sake of simplicity in the illustration, the grooves and blocks of the tread band are not shown. [Figure 1A] This is a schematic perspective view of a further radial cross-section of a motorcycle tire according to the present invention, where the grooves and blocks of the tread band are not shown for the sake of simplicity in the illustration. [Figure 2] This is a schematic diagram of the radial cross-section of a motorcycle tire according to the present invention. [Modes for carrying out the invention]

[0241] Referring to Figures 1 and 2, reference numeral 1 indicates a motorcycle tire according to the present invention.

[0242] The tire shown is the rear tire, but the following description also applies to the front tire unless otherwise specifically mentioned.

[0243] Tire 1 is for high displacement (e.g., 1000cm²) 3 These are motorcycle tires designated as "big enduro" tires, which have a high output (e.g., equal to 100 hp) and a mass of, for example, 200 kg or more in riding position.

[0244] Tire 1 is generally intended to be mounted on a wheel rim having a maximum radial cross-sectional width in the range of 90 to 170 (e.g., 90 to 120 for front tires, and 130 to 170 for rear tires) and a mounting diameter in the range of approximately 17 inches to approximately 21 inches (e.g., 19 to 21 inches for front tires, and 17 to 18 inches for rear tires).

[0245] An equatorial plane "XX" and a rotation axis R (not shown) are defined on tire 1. A circumferential direction is defined according to the direction of rotation of tire 1, and therefore parallel to the equatorial plane XX, as well as an axial direction perpendicular to the equatorial plane "XX" and / or parallel to the rotation axis.

[0246] The tire 1 comprises a radial carcass structure 2 formed from a first carcass ply 3a and a second carcass ply 3b.

[0247] The first carcass ply 3a consists of a sheet of elastomer material incorporating the first plurality of textile reinforcing cords 30.

[0248] The second carcass ply 3b consists of a sheet of elastomer material incorporating a second set of textile reinforcing cords 32.

[0249] The elastomer material used to make the sheet of elastomer material for the first carcass ply 3a is the same as the elastomer material used to make the sheet of elastomer material for the second carcass ply 3a.

[0250] In one embodiment, the first ply 3a is made by joining together multiple strips of elastomer material reinforced with a first plurality of textile reinforcing cords 30.

[0251] In one embodiment, the second ply of the carcass 3b is made by joining together multiple strips of elastomer material reinforced with a second plurality of textile reinforcing cords 32.

[0252] The textile reinforcing cords 31 of the first plurality of textile reinforcing cords 30 are arranged substantially parallel to each other and are substantially oriented along the axial direction. The textile reinforcing cords 31 of the first plurality of textile reinforcing cords 30 have a first inclination of a predetermined inclination angle A1 with respect to the equatorial plane XX of the tire at the crown portion 8C of the tread band. Each textile reinforcing cord 31 of the first plurality of textile reinforcing cords 30 belongs to the respective radial plane of the tire 1.

[0253] Similarly, the textile reinforcing cords 33 of the second plurality of textile reinforcing cords 32 are arranged substantially parallel to each other and oriented substantially along the axial direction. The textile reinforcing cords 33 of the second plurality of textile reinforcing cords 32 have a second inclination of the same predetermined inclination angle A1 as the textile reinforcing cords 31 of the first plurality of textile reinforcing cords 30 with respect to the equatorial plane XX of the tire. Each textile reinforcing cord 33 of the second plurality of textile reinforcing cords 32 belongs to the respective radial plane of the tire 1.

[0254] Such predetermined inclination angles A1 fall within the absolute range of 65° to 90° with respect to the circumferential direction. The first inclination is in the opposite direction to the second inclination with respect to the circumferential direction. In other words, the predetermined inclination angle A1 of the first inclination is measured along the first angular direction with respect to the circumferential direction, and the predetermined inclination angle A1 of the second inclination is measured along the second angular direction with respect to the circumferential direction, with the first and second angular directions being opposite.

[0255] In a preferred embodiment of the present invention, the predetermined inclination angle A1 is an absolute value of approximately 70°.

[0256] As best shown in Figure 1, the first carcass ply 3a and the second carcass ply 3b are radially juxtaposed, preferably radially adjacent. The second carcass ply 3b is radially outward relative to the first carcass ply 3a.

[0257] The textile reinforcement cords 31 and 33 of the first set of textile reinforcement cords 30 and the second set of textile reinforcement cords 32 are identical to one another.

[0258] The radial carcass structure 2 is typically covered on its inner wall by a sealing layer 100, a so-called "liner," which essentially consists of an airtight layer of elastomer material configured to ensure an airtight seal of the tire 1 itself when inflated.

[0259] The first carcass ply 3a and the second carcass ply 3b are substantially toroidal in shape, as best shown in Figure 1, and have axial side edges 3c, 3d on each side, which are folded over by the respective annular reinforcement structures 4. The annular reinforcement structures 4 are intended to hold the tire 1 to the corresponding mounting rim (not shown). The annular reinforcement structures 4 are typically referred to as the "bead core".

[0260] A tapered elastomer filler 5 is applied to the outer edge of the bead core 4, occupying the space defined between the first carcass ply 3 and the folded side edge 3c of the first carcass ply 3a.

[0261] In an alternative embodiment, although not shown, the first carcass ply 3a and the second carcass ply 3b may have side edges 3c, 3d on both sides, which are associated with a specific annular reinforcing structure having two metal annular inserts without being folded over.

[0262] The area of ​​the tire 1 comprising the bead core 4 and elastomer filler 5 forms a so-called bead 9, which is intended to secure the tire 1 to a rim (not shown).

[0263] The tire 1 comprises a pair of sidewalls 7 applied laterally to both sides of a radial carcass structure 2.

[0264] In a possible preferred embodiment, the rigidity of the sidewall 7 of the tire 1 can be improved by providing a reinforcing layer 12 (shown in Figure 2, not shown in Figure 1) or an additional strip-shaped insert on the bead 9, which is commonly known as a "flipper".

[0265] The flippers 12 are reinforcing layers wrapped around each bead wire 4 and elastomer filler 5, at least partially enclosing them. Such reinforcing layers are positioned between the radial carcass structure 2 and the bead 9.

[0266] Preferably, the flipper 12 is in contact with the first carcass ply 3a and the bead 9.

[0267] In a possible preferred embodiment, the bead 9 may be provided with an additional protective layer 13 (shown in Figure 2, not shown in Figure 1) commonly known as a “chafer” or protective strip, which serves to increase the rigidity and integrity of the bead 9.

[0268] In a preferred embodiment, the carcass reinforcement structure 11 is located radially outward from the radial carcass structure 2. Such a carcass reinforcement structure 11 includes a crown ply 11a located radially outward from the second carcass ply 3b and positioned on at least one crown portion of the second carcass ply 3b.

[0269] The crown ply 11a comprises reinforcing elements arranged parallel to each other. The crown ply 11a is positioned on the second carcass ply 3b such that the reinforcing elements of the crown ply 11a are at opposite angles to the reinforcing elements of the second carcass ply 3b with respect to the equatorial plane. Optionally, the carcass reinforcement structure 11 also comprises two plies (not shown) positioned on either side of the crown ply 11a and not associated with their respective beads.

[0270] The belt structure 6 (shown in Figure 2) is applied circumferentially to the radial carcass structure 2 at a position radially outward.

[0271] The belt structure 6 comprises a belt layer 6a having at least one reinforcing cord 6b that forms multiple windings.

[0272] Preferably, the belt structure 6 is of the zero-degree type, i.e., the belt layer 6a is made up of reinforcing cords 6b arranged substantially parallel to each other to form multiple windings. The orientation of such windings is substantially circumferential (typically an angle between 0° and 5°), and such orientation is usually referred to as "zero-degree" in reference to how it is arranged with respect to the circumferential direction of the tire 1.

[0273] Preferably, the belt layer 6a comprises axially aligned windings of a ribbon-like reinforcing element of rubberized fabric, which includes a plurality of axially aligned reinforcing cords 6b that form a plurality of windings oriented substantially in accordance with the circumferential direction of the tire 1.

[0274] When a ribbon-like reinforcing element is used, it may comprise up to seven reinforcing cords 6b, more preferably three.

[0275] Preferably, the windings defined by the windings extend axially across the entire crown portion of the radial carcass structure 2, and the pitch of the windings is preferably constant in the axial direction.

[0276] The reinforcing cord 6b of the belt layer 6a is made of metal, specifically steel wire with a high carbon content, i.e., steel wire with a carbon content of at least 0.6 to 0.7% by weight. Preferably, such metal cord has high elongation (HE).

[0277] The belt structure 6 has tread bands 8 arranged circumferentially thereon, and the tread bands 8 have circumferential and transverse grooves 10 formed thereon, typically arranged to define the boundaries of multiple blocks, after a molding process that is carried out simultaneously with the vulcanization step of the tire 1.

[0278] Referring to Figure 1, the tire 1 has a cross-sectional height "H" measured between the top of the tread band 8 and the mounting diameter, which is determined by a reference line "r" passing through the bead 9 of the tire 1, at the equatorial plane "XX".

[0279] The tire 1 also has a maximum radial cross-sectional width "C" defined by the distance between the lateral ends "E" of the tread band 8, and an arrow "f" defined by the distance from a line passing through the lateral ends "E" to the top of the tread band 8, measured at the equatorial plane "XX" of the tire 1. The lateral ends "E" of the tread band 8 can be formed to have edges.

[0280] Tire 1 has a "curvature ratio" (f / C) defined by the ratio of the arrow "f" to the aforementioned maximum radial cross-sectional width "C".

[0281] Tire 1 has a ratio of "arrow to total height" (f / H) given by the ratio of arrow "f" to the cross-sectional height "H".

[0282] The indicated reference symbols ("H", "XX", "r", "C", "f", "E") are the same for both the front and rear tires.

[0283] Preferably, the arrow "f" of tire 1 is located between approximately 40mm and 60mm.

[0284] Tire 1 has a curvature ratio "f / C" that falls within the range of approximately 0.25 to approximately 0.35, for example, a curvature ratio "f / C" equal to approximately 0.26.

[0285] Tire 1 has an arrow-to-overall height ratio "f / H" that falls within the range of approximately 0.40 to approximately 0.60, for example, an "f / H" equal to approximately 0.43.

[0286] For the front tire, the arrow "f" falls within a range of approximately 35mm to 60mm, and the curvature ratio "f / C" falls within a range of approximately 0.30 to 0.40, which is equal to, for example, 0.38.

[0287] In the case of the front tires, the ratio of the arrow to the overall height "f / H" falls within the range of approximately 0.40 to 0.60, and is, for example, equal to approximately 0.53.

[0288] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 incorporated into the first carcass ply 3a and the second carcass ply 3b, respectively, have a tensile strength greater than 0.52 cN / Tex at 2% elongation.

[0289] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 incorporated into the first carcass ply 3a and the second carcass ply 3b, respectively, have a tensile strength of less than 0.65 cN / Tex at 2% elongation.

[0290] For example, the tensile strength of the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 is 0.57 cN / Tex at 2% elongation.

[0291] In a preferred embodiment of the present invention, the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a tensile strength greater than 0.87 cN / Tex at 5% elongation.

[0292] In a preferred embodiment of the present invention, the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a tensile strength of less than 1.2 cN / Tex at 5% elongation.

[0293] For example, the tensile strength of the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 is 1 cN / Tex at 5% elongation.

[0294] A preferred material for producing the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 is nylon 6.6.

[0295] In a preferred embodiment of the present invention, the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a linear density greater than 2600 dTex.

[0296] In a preferred embodiment of the present invention, the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a linear density less than 3000 dTex.

[0297] For example, the textile reinforcement cords 31 and 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a linear density of 2800 dTex.

[0298] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have a linear density higher than 1300 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0299] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have a linear density of less than 1500 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcing cord.

[0300] For example, the textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a linear density of 1400 × 2 dTex, where the term × 2 represents the number of ends of yarn twisted together in each reinforcement cord.

[0301] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have a thread count greater than 105 cords / dm.

[0302] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have a thread count of less than 120 cords / dm.

[0303] For example, the textile reinforcement cords 31 and 33 of the first plurality of textile reinforcement cords 30 and the second plurality of textile reinforcement cords 32 have a thread count of 112 cords / dm.

[0304] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have twists applied to each end and the entire end forming the textile reinforcing cord, forming more than 38 twists and 42 twists per decimeter.

[0305] In a preferred embodiment of the present invention, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have a twist imparted to each end and the entirety of the ends forming the textile reinforcing cord, with fewer than 42 twists per decimeter.

[0306] For example, the textile reinforcing cords 31, 33 of the first plurality of textile reinforcing cords 30 and the second plurality of textile reinforcing cords 32 have fewer than 40 twists per decimeter, with each end and each end forming the textile reinforcing cord having a twist.

[0307] The tread band 8 comprises at least one central annular sector 8a (illustrated in Figure 2) made of elastomer material and positioned across the equatorial plane XX.

[0308] According to a preferred embodiment of the present invention, the tread band 8 may be of the so-called "cap and base" type or made of two different elastomer materials.

[0309] In a preferred embodiment of the present invention, the tread band 8 has a central annular sector 8a, as well as two lateral annular sectors 8b arranged symmetrically on both sides with respect to the equatorial plane XX of the tire and adjacent to the central annular sector.

[0310] The two lateral annular sectors 8b are made of an elastomer material different from the elastomer material from which the central annular sector 8a is made.

[0311] The central annular sector 8a has an axially extending portion with a width greater than 18% of the width of the tread band 8.

[0312] The central annular sector 8a has an axially extending portion with a width less than 26% of the width of the tread band 8.

[0313] In a preferred embodiment of the present invention, the central annular sector 8a has an axially extending portion with a width greater than 20 percent of the width of the tread band.

[0314] In a preferred embodiment of the present invention, the central annular sector 8a has an axially extending portion with a width less than 24%.

[0315] For example, the central annular sector 8a has an axially extending portion with a width equal to 22% of the width of the tread band 8.

[0316] The two lateral annular sectors 8b are arranged at respective distances along the axial extension, with respect to the equatorial plane X-X, greater than 9% of the axial extension of the tread band 8, preferably greater than 11% of the axial extension of the tread band 8.

[0317] The axial extensions of the two lateral annular sectors have equal widths.

[0318] The sum of the widths of the axial extension of the two lateral annular sectors 8b and the axial extension of the central annular sector 8a matches the width of the axial extension of the tread band 8.

[0319] Typically, for the tire compound according to the present invention, the components listed below and other components typically used in the tire industry can be used.

[0320] In particular, for the tread compounds of the lateral annular sector 8b and the central annular sector 8a, it is possible to use an elastomer composition that includes at least one diene elastomer polymer selected from, for example, diene elastomer polymers commonly used in sulfur crosslinkable elastomer compositions (vulcanization), peroxides or other systems known to those skilled in the art and particularly suitable for tire manufacturing, or elastomer polymers or copolymers having unsaturated chains with a glass transition temperature (Tg) usually less than 20°C, preferably in the range of 0°C to -110°C.

[0321] Preferably, the tread compound of the lateral annular sector 8b and the central annular sector 8a contains at least one diene elastomer polymer in 100 phr, with at least one styrene-butadiene rubber (dry polymer) selected from solution styrene-butadiene rubber (S-SBR), emulsion styrene-butadiene rubber (E-SBR), or a mixture thereof, in an amount contained in 50 to 90 phr.

[0322] Examples of commercially available SBR polymers useful in the present invention include Tufdene polymers E581 and E680 from Ashai-Kasei (Japan), SPRINTAN SLR4602, SLR3402 and SLR4630 from Trinseo (Germany), HPR621 from JSR Corporation (Japan), BUNA SL-4518, BUNA SE 1502 and BUNA CB 22 from Arlanxeo (Germany), Europrene 5543T, Europrene 1739 and Intol 1789 from Versalis (Italy), HP 755 from Japan Synthetic Rubber Co. (Japan), and NIPOL NS 522 from Zeon Co. (Japan).

[0323] Preferably, the tread compounds of the lateral annular sector 8b and the central annular sector 8a include at least one butadiene polymer (BR) with a density of 10 to 50 phr, preferably a low-cis functionalized BR.

[0324] Preferably, the tread compounds of the lateral annular sector 8b and the central annular sector 8a comprise one or more liquid polymers selected from 1 to 20 phr of alkylene-based liquid polymers and copolymers, preferably butadiene-based (BR), isoprene (IR), isoprene / butadiene (IBR), styrene / butadiene (SBR), optionally functionalized hydroxy and epoxy, or natural depolymerized liquid polymers (NR).

[0325] Preferably, one or more liquid polymers are selected from butadiene-based liquid polymers (BR).

[0326] Preferably, the tread compound of the lateral annular sector 8b and the central annular sector 8a comprises at least one resin.

[0327] Preferably, the resin is a polyterpene resin selected from alpha-pinene, beta-pinene, limonene, and homo- or copolymers of vinyl aromatic monomers (styrene) and / or aromatic monomers (phenol).

[0328] Examples of commercially available terpene-based natural resins include Piccolyte F90 and Piccolyte F105 resins manufactured by PINOVA, and Dercolyte A 115 and Dercolyte M 115 manufactured by DRT.

[0329] At least one of the resins can be a hydrocarbon.

[0330] Preferably, the hydrocarbon resin is selected from coumarone-indene, styrene-indene, styrene-alkylstyrene, and aliphatic resins.

[0331] A specific example of a commercially available hydrocarbon resin is NOVARES C resin (synthetic indene-coumarone resin) manufactured by RUTGERS CHEMICAL GmbH, with NOVARES C10, C30, and C90 being particularly preferred.

[0332] Examples of commercially available styrene-indene hydrocarbon resins include UNILENE A 100 manufactured by Braskem and Novares TT 90 manufactured by Ruetgers.

[0333] Preferably, at least one resin is present in an amount of 5 to 50 phr, more preferably 10 to 40 phr.

[0334] Preferably, the tread compound of the lateral annular sector 8b and the central annular sector 8a according to the present invention comprises at least one plasticizing oil.

[0335] The term "plasticizing oil" refers to process oils derived from petroleum or mineral oil, or oils of plant or synthetic origin, or combinations thereof.

[0336] Plasticizing oils can be petroleum-derived process oils selected from paraffins (saturated hydrocarbons), naphthenes, aromatic polycyclic substances, and mixtures thereof.

[0337] Suitable examples of petroleum-derived process oils include aromatic, paraffinic, and naphthenic oils, such as MES (Mild Extract Solvated), DAE (Distilled Aromatic Extract), TDAE (Treated Distilled Aromatic Extract), TRAE (Treated Residual Aromatic Extract), and RAE (Residual Aromatic Extract), which are known in the industry.

[0338] Plasticizing oils may be naturally occurring or synthetically occurring oils derived from the esterification of glycerol with fatty acids, including glycerol triglycerides, diglycerides, monoglycerides, or mixtures thereof.

[0339] Suitable vegetable oils include sunflower oil, soybean oil, linseed oil, rapeseed oil, castor oil, and cottonseed oil.

[0340] Examples of oils used in compounds include tri-(2-ethylhexyl)-phosphate (TOF) and Lanxess.

[0341] Plasticizing oils may be synthetic oils selected from alkyl or aryl esters of phthalic acid or phosphoric acid.

[0342] Preferably, oils of natural (e.g., plant) or synthetic origin have a glass transition temperature (Tg) of less than -70°C (according to ISO 28343:2010).

[0343] Suitable examples of commercially available plasticizers include petroleum-based oils: NYTEX 4700 sold by Nynas, EXTENSOIL 1471 sold by Repsol, and VIVATEC 500 sold by H&R; and vegetable oils: RADIA 6132RADIA sold by Oleon, and Agripure AP 18 and Agripure AP 75 sold by Cargill.

[0344] Preferably, the total amount of oil, including both the oil added as a diluent for the elastomeric polymer and any oil already present, is 10 to 70 phr, more preferably 20 to 60 phr.

[0345] The elastomer composition for tires according to the present invention may contain at least one reinforcing filler in an amount of at least 20 phr, preferably at least 30 phr, more preferably at least 40 phr, and even more preferably at least 50 phr.

[0346] This composition may contain at least one reinforcing filler with a strength of 10 phr to 150 phr or 30 phr to 120 phr.

[0347] Preferably, the reinforcing filler is selected from carbon black, white filler, silicate fibers, and mixtures thereof.

[0348] In one embodiment, the reinforcing filler is a white filler selected from hydroxides, oxides and hydrated oxides, metal salts and hydrated salts, silicate fibers, or mixtures thereof. Preferably, the white filler is silica.

[0349] Preferably, silica is present in the elastomer composition in an amount of 10 phr to 130 phr, more preferably 40 phr to 110 phr, and even more preferably 70 to 100 phr.

[0350] Suitable commercially available examples of conventional silica include Solvay's Zeosil 1165 MP and Evonik's Ultrasil 7000 GR.

[0351] In one embodiment, the reinforcing filler is carbon black.

[0352] Preferably, carbon black is present in the elastomer composition in an amount containing 1 phr to 100 phr, more preferably 5 phr to 70 phr.

[0353] Preferably, the carbon black is selected from those having a surface area of ​​20 m² / g or more, preferably greater than 50 m² / g (determined by the statistical thickness specific surface area according to STSA-ISO 18852:2005).

[0354] Carbon black can be, for example, N234, N326, N330, N375 or N550, N660 sold by Birla Group (India), or CRX 1391 manufactured by Cabot Corporation.

[0355] Preferably, the reinforcing filler comprises carbon black and silica, particularly preferably 2 to 15 phr of carbon black and 40 to 110 phr of silica, more preferably 5 to 10 phr of carbon black and 70 to 100 phr of silica.

[0356] The elastomer composition for tire compounds preferably contains at least one vulcanizing agent in an amount of at least 0.7 phr, more preferably at least 1 phr.

[0357] The elastomer composition for tire compounds preferably contains 0.5 to 7 phr, more preferably 1 to 5 phr of vulcanizing agent.

[0358] At least one vulcanizing agent is preferably selected from sulfur, or instead from sulfur-containing molecules (sulfur donors), such as bis[(trialkoxysilyl)propyl]polysulfide, and mixtures thereof.

[0359] Preferably, the vulcanizing agent is sulfur, and is preferably selected from soluble sulfur (crystalline sulfur), insoluble sulfur (polymeric sulfur), oil-dispersible sulfur, and mixtures thereof.

[0360] Examples of commercially available vulcanizing agents suitable for use in the elastomer composition of the present invention include Rhenocure® IS90P from RheinChemie or Redball Superfine sulfur from International Sulphur Inc.

[0361] In this elastomer compound, the vulcanizing agent can be used together with adjuvants such as vulcanizing activators, accelerators, and / or inhibitors known to those skilled in the art.

[0362] The elastomer compound may, in some cases, contain at least one vulcanizing activator.

[0363] Suitable vulcanizing activators for use in this elastomer compound are zinc compounds, particularly ZnO, ZnCO3, and zinc salts of saturated or unsaturated fatty acids containing 8 to 18 carbon atoms, which are preferably formed in situ in the elastomer compound by a reaction between ZnO and fatty acids or mixtures thereof. For example, preferably, zinc stearate formed in situ in the elastomer compound from ZnO and fatty acids, or magnesium stearate formed from MgO, or mixtures thereof are used.

[0364] The vulcanizing activator may be present in the elastomer compound of the present invention in an amount of preferably 0.2 phr to 15 phr, more preferably 1 phr to 5 phr.

[0365] The preferred activator is derived from the reaction of zinc oxide and stearic acid.

[0366] Examples of activators include Aktiplast ST Rheinchemie and zinc bis-neodecanoate VALIKAT Zn 1910 Umicore.

[0367] The elastomer compound may further contain at least one vulcanization accelerator.

[0368] Primary and secondary vulcanization accelerators can generally be selected from, for example, dithiocarbamates, guanidines, thioureas, thiazoles, sulfenamides, sulfenimides, thiurams, amines, xanthetes, or mixtures thereof.

[0369] Preferably, the accelerator is selected from mercaptobenzothiazole (MBT), N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (TBBS) dibenzothiazole disulfide (MBTS), and mixtures thereof.

[0370] Examples of commercially available accelerators suitable for use with this elastomer compound include Vulkacit® N-cyclohexyl-2-benzothiazolyl sulfenamide (CBS or CZ) sold by Lanxess, and N-tert-butyl-2-benzothiadyl sulfenamide, Vulkacit® NZ / EGC, tetrabenzyl thiuram disulfide (Perkacit® TBzTD), dibenzothiazole disulfide Rhenogran MBTS 80, and N-tert-butyl-2-benzothiadyl sulfenamide manufactured by Huatai Chemicals TBBS.

[0371] The vulcanization accelerator can be used in this elastomer compound in an amount of preferably 0.05 phr to 10 phr, preferably 0.1 phr to 7 phr, and more preferably 0.5 phr to 5 phr.

[0372] The elastomer compound may, in some cases, contain at least one vulcanization inhibitor.

[0373] Suitable vulcanization inhibitors for use in elastomer compounds are preferably selected from urea, phthalic anhydride, N-nitrosodiphenylamine N-cyclohexylthiophthalimide (CTP or PVI), and mixtures thereof.

[0374] A suitable commercially available inhibitor is VULKALENT G, an N-cyclohexylthiophthalimide manufactured by Lanxess.

[0375] The vulcanization inhibitor may be present in the elastomer compound in an amount of preferably 0.05 phr to 2 phr.

[0376] This elastomer compound may contain one or more of the vulcanization inhibitors specified above in the mixture.

[0377] The elastomer compound may further contain at least one silane coupling agent in an amount of at least 0.05 phr, preferably at least 0.1 phr or 0.5 phr, more preferably at least 1 phr or 2 phr.

[0378] Preferably, the elastomer compound contains at least one silane coupling agent in a concentration of 0.5 phr to 10.0 phr, more preferably 1.0 phr to 8.0 phr, and even more preferably 5 to 8 phr.

[0379] Preferably, the coupling agent is a silane coupling agent selected from those having at least one hydrolyzable silane group, which is, for example, the following general formula (III): (R')3Si-CnH2n-X (III) (In the formula, the R' groups may be the same or different, and are selected from alkyl, alkoxy, or aryloxy groups, or halogen atoms, provided that at least one of the R' groups is an alkoxy or aryloxy group; n is an integer from 1 to 6; X is a group selected from nitroso, mercapto, amino, epoxide, vinyl, imide, chlorine, -(S)mCnH2n-Si-(R')3, and -S-COR', where m and n are integers from 1 to 6, and the R' group is defined as above.) It can be identified by this.

[0380] Particularly preferred silane coupling agents are bis(3-triethoxysilyl-propyl)tetrasulfide and bis(3-triethoxysilyl-propyl)disulfide. The coupling agents can be added as is or in mixtures with inert fillers (e.g., carbon black) to promote their incorporation into elastomer compounds.

[0381] An example of a silane coupling agent is TESPT: bis(3-triethoxysilylpropyl)tetrasulfide Si69, sold by Evonik.

[0382] The elastomer compound may further contain one or more additional components commonly used in this industry, such as antioxidants and / or ozone inhibitors (degradation inhibitors), waxes, adhesives, and the like.

[0383] The elastomer compound may, in some cases, contain at least one wax.

[0384] For example, the wax could be a mixture of petroleum wax or paraffin.

[0385] Suitable commercially available waxes include N-paraffin from Repsol and Antilux® 654 crystalline cellulose wax from Rhein Chemie.

[0386] The wax may generally be present in the elastomer compound in a total amount of 0.1 phr to 20 phr, preferably 0.5 phr to 10 phr, and more preferably 1 phr to 5 phr.

[0387] The elastomer compound may, in some cases, contain at least one antioxidant.

[0388] The antioxidants are preferably N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), N-(1,3-dimethyl-butyl)-N'-phenyl-p-phenylenediamine (6PPD), N,N'-bis-(1,4-dimethyl-pentyl)-p-phenylenediamine (77PD), N,N'-bis-(1-ethyl-3-methylpentyl)-p-phenylenediamine (DOPD), N,N'-bis-(1,4-dimethylpentyl)-p-phenylenediamine, N,N'-diphenyl-p-phenylenediamine (DPPD), and N,N'-ditril-p-phenylenediamine. It is selected from phenylenediamine (DTPD), N,N'-di-beta-naphthyl-p-phenylenediamine (DNPD), N,N'-bis(1-methylheptyl)-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine (44PD), N-phenyl-N'-cyclohexyl-p-phenylenediamine, N-phenyl-N'-1-methylheptyl-p-phenylenediamine and similar, as well as mixtures thereof, and preferably it is N-1,3-dimethylbutyl-N-phenyl-p-phenylenediamine (6-PPD).

[0389] A suitable commercially available antioxidant is 6PPD manufactured by Solutia / Eastman.

[0390] The antioxidant may be present in the elastomer composition in a total amount of preferably 0.1 phr to 20 phr, preferably 0.5 phr to 10 phr.

[0391] All elastomer compositions used in tires according to the present invention may contain the aforementioned components and other additives that are generally selected based on the specific application for which each composition is intended.

[0392] In a preferred embodiment of the present invention, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static modulus of elasticity Ca3 in the central annular sector 8a that is measured at 70°C and ranges from 9.0 to 14.0, a tandelta 8a that is measured at 70°C and ranges from 0.120 to 0.160, and a dynamic modulus of elasticity E' that is measured at 70°C and ranges from 3.7 to 4.1.

[0393] Preferably, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static elastic modulus Ca3 greater than 10.8 when measured at 70°C in the central annular sector 8a.

[0394] Preferably, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static elastic modulus Ca3 less than 11.9 when measured at 70°C in the central annular sector 8a.

[0395] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static elastic modulus Ca3 of 11.5 when measured at 70°C in the central annular sector 8a.

[0396] Preferably, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a tandelta greater than 0.138 when measured at 70°C and 10Hz in the central annular sector 8a.

[0397] Preferably, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a tandelta of less than 0.152 when measured at 70°C and 10Hz in the central annular sector 8a.

[0398] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a tandelta of 0.145 when measured at 70°C and 10Hz in the central annular sector 8a.

[0399] In a preferred embodiment of the present invention, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a dynamic modulus of elasticity E' greater than 3.8 when measured at 70°C and 10Hz in the central annular sector 8a.

[0400] In a preferred embodiment of the present invention, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a dynamic modulus of elasticity E' less than 4.0 when measured at 70°C and 10Hz in the central annular sector 8a.

[0401] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a dynamic modulus of elasticity E' of 3.9 when measured at 70°C and 10Hz in the central annular sector 8a.

[0402] In a preferred embodiment of the present invention, the ratio of the tan delta of the elastomer material of the central annular sector 8a of the tread band 8, measured at 70°C and 10Hz, to the dynamic modulus of elasticity E', measured at 70°C and 10Hz, is greater than 0.034.

[0403] In a preferred embodiment of the present invention, the ratio of the tandelta of the elastomer material of the central annular sector 8a of the tread band 8, measured at 70°C and 10Hz, to the dynamic modulus of elasticity E', measured at 70°C and 10Hz, is less than 0.039.

[0404] For example, the ratio of the tan delta of the elastomer material in the central annular sector 8a of tread band 8, measured at 70°C and 10Hz, to the dynamic modulus of elasticity E', also measured at 70°C and 10Hz, is 0.037.

[0405] Preferably, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a tandelta in the central annular sector 8a that is smaller than the tandelta of the vulcanized elastomer material of the two lateral annular sectors 8b, measured at 70°C and 10Hz.

[0406] The elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a dynamic modulus of elasticity E' measured at 70°C and 10Hz that is greater than the dynamic modulus of elasticity E' measured at 70°C and 10Hz of the vulcanized elastomer material of the two lateral annular sectors 8b.

[0407] The elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static modulus of elasticity Ca3 measured at 70°C that is greater in the central annular sector 8a than in the vulcanized elastomer material of the two lateral annular sectors 8b measured at 70°C.

[0408] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a tandelta in the central annular sector 8a that is equal to 92% of the tandelta in the two lateral annular sectors 8b measured at 70°C and 10Hz.

[0409] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a dynamic modulus of elasticity E' measured at 70°C and 10Hz that is equal to 106% of the dynamic modulus of elasticity E' measured at 70°C and 10Hz of the vulcanized elastomer material of the two lateral annular sectors 8b.

[0410] For example, the elastomer material of the central annular sector 8a of the tread band 8 is selected such that the final (vulcanized) tire has a static modulus of elasticity Ca3 measured at 70°C that is equal to 130% of the static modulus of elasticity Ca3 of the vulcanized elastomer material of the lateral annular sector 8b measured at 70°C in the central annular sector 8a.

[0411] Official Exam The applicant has produced a sample of a rear tire 1 according to an embodiment of the present invention. Hereinafter, such a tire will be referred to as INV.

[0412] The tire INV had the same dimensions as the applicant's currently available rear tires for motorcycles, which are primarily intended for use on public roads and have limited off-road use. Such tires are referred to as Ref below.

[0413] The structures of the INV and Ref tires were identical in terms of their belt and bead structures, and both had a cap and base type tread band. In particular, both tires had a central annular sector and two lateral annular sectors of the same axial dimension.

[0414] The two tires had the characteristics shown in Table 1 regarding their carcass structure.

[0415] [Table 1]

[0416] As can be seen from Table 1 above, the reinforcing cord used in the carcass ply according to the present invention has lower mechanical properties compared to the reinforcing cord of the comparative tire.

[0417] The elastomer compositions used to produce the vulcanized elastomer material for the lateral annular portions of the two tires are identical and are shown in the column labeled "Lateral Portion" in Table 2.

[0418] Table 2 shows the elastomer compositions used to produce the vulcanized elastomer material for the central annular sector of the two tires.

[0419] [Table 2] S-SBR: Solution-polymerized styrene-butadiene rubber, spread with 37.5 parts TDAE oil per 100 parts dry polymer (110 phr of spread polymer corresponds to 80 phr of dry polymer, 96.2 phr of spread polymer corresponds to 70 phr of dry polymer, and 100.4 phr of spread polymer corresponds to 73 phr of dry polymer), Tufdene E680, Asahi Kasei. Functionalized BR: Low-cis functionalized polybutadiene YB03, Asahi Kasei BR: High-cis polybutadiene EUROPRENE NEOCIS BR 60 from solution, Versalis CB1: Carbon Black CRX 1391, Cabot CB2: Carbon Black N234, Cabot Silica 1: ZEOSIL 1165 MP, Solvay Silica 2: ULTRASIL 7000, Evonik TDAE oil-treated distillate aromatic extract, Vivatec® 500 (plasticizer), Hansen & Rosenthal, Germany Liquid Butadiene 1:RICON 100, Cray Valley Liquid Butadiene 2: Polyvest 130, Evonik TOF plasticizer: Tri-(2-ethylhexyl)-phosphate (TOF), Lanxess Terpene resin: Resin 2495, Pinova Styrene indene resin: Novares TT90; Reutgers Germany GmbH Zinc salt 1: Zinc bis-neodecanoate VALIKAT Zn 1910 Umicore Zinc salt 2: Zinc stearate Aktiplast ST (Rheinchemie) Zinc salt 3:75% zinc octanoate, Purus Silane: Si 69(registered trademark)-Bis[3-(triethoxysilyl)propyl]polysulfide, Evonik Wax: N-paraffin and isoparaffin mixture BMO1, Repsol 6PPD:N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine, Solutia Eastman; Sulfur: Rhenocure (registered trademark) IS 90 P (Rhein Chemie) TBBS: N-tert-butyl-2-benzothiazilsulfenamide, manufactured by Huatai Chemicals. MBTS 80: Rhenogran MBTS 80 Dibenzothiazole Disulfide, Rhein Chemie TBzTD: Tetrabenzylthioram disulfide (Perkacit® TBZTD) DPG 80: N,N'-Diphenylguanidine accelerator Rhenogran(registered trademark) RheinChemie PVI N-cyclohexylthiophthalimide, manufactured by Brenntag Spa, Milan, Italy.

[0420] Table 3 below shows the results of static and dynamic mechanical analysis performed on samples of vulcanized elastomer materials used in the central annular sector of the tire and comparative tire according to the present invention, obtained by vulcanizing the elastomer compositions shown in Table 2 above.

[0421] The elastomer material was obtained by vulcanizing the elastomer composition shown in Table 2 above at 170°C for 15 minutes.

[0422] [Table 3]

[0423] As can be seen from Table 3 above, the elastomer material used in the central annular sector of the tire according to the present invention has a static stiffness under deformation that is 300% higher than the corresponding static stiffness of the elastomer material used in the central annular sector of the comparative tire: according to the applicant, this property may be a predictor of high driving stability. The elastomer material used in the central annular sector of the tire according to the present invention has a dynamic modulus at 70°C that is slightly higher than that of the comparative tire at 70°C, and a significantly lower tandelta, resulting in a tandelta / E' ratio that can correlate with a parameter index of tire grip being lower than that of the elastomer material used in the central annular sector of the comparative tire. Such a low tandelta / E' ratio in the crown portion of the tread band of the tire according to the present invention should be a predictor of deterioration in tire grip performance. Surprisingly, the driving tests conducted (as described below) yielded the opposite results.

[0424] We conducted outdoor comparative tests using the Ref tire, which is highly regarded by customers for its excellent on-road performance and above-average off-road performance.

[0425] The tests were conducted under identical environmental conditions, specifically at temperatures of 10°C to 40°C for dry asphalt tests and 10°C to 20°C for wet asphalt tests. Both tires (pressurized to the same tire pressure of 2.9 bar) were mounted on the rear wheel of a BMW R1250 GS motorcycle, and the same tire was mounted on the front wheel.

[0426] The behavior of the two tires, INV and Ref, was evaluated by the driver's judgment on both (dry and wet) roads and non-extreme off-road conditions. In particular, the items listed in Table 4 below were evaluated, and the driver's comments are also included.

[0427] Road tests were conducted by driving on both dry and wet roads, covering both straight and curved sections.

[0428] In Table 4, "=" indicates a positive evaluation obtained for the Ref. tire, "+" indicates an improvement over the Ref. tire, and "++" indicates an even greater improvement over the Ref. tire.

[0429] [Table 4]

[0430] Table 4 shows that the INV tire offers improved road surface performance compared to the Ref tire, particularly in terms of stability and handling in both dry and wet conditions.

[0431] The tests also showed that the INV tires performed better than the Ref tires in terms of comfort on dry surfaces, comfort in terms of driving safety in dry conditions, and braking in wet conditions.

[0432] The applicant has therefore confirmed that by using a cross-ply carcass structure and tread band having adapted characteristics in the tire of the present invention, it has been possible to achieve a very desirable improvement in high-speed stability on the road surface, with a remarkable improvement in handling in both dry and wet conditions.

[0433] Of course, a person skilled in the art could make further modifications and alterations to tire 1 above to satisfy specific and extraordinary application requirements, and in any case such modifications and alterations would be included within the scope of protection as defined by the following claims.

Claims

1. A motorcycle tire (1) comprising a radial carcass structure (2) and a tread band (8) applied to the radial carcass structure (2) at a radially outward position, The radial carcass structure (2) comprises a first carcass ply (3a) including a first plurality of textile reinforcing cords (30) and a second carcass ply (3b) including a second plurality of textile reinforcing cords (32), The textile reinforcing cords (31) of the first plurality of textile reinforcing cords (30) are substantially parallel to each other, and the crown portion (8c) of the tread band (8) has a first inclination of a predetermined inclination angle (A1) with respect to the equatorial plane (X-X) of the tire, and the textile reinforcing cords (33) of the second plurality of textile reinforcing cords (32) are substantially parallel to each other, and the crown portion (8c) of the tread band (8) has a second inclination of the predetermined inclination angle (A1) with respect to the equatorial plane (X-X) of the tire, and the second inclination is in the opposite direction to the first inclination. The second carcass ply (3b) is radially positioned on the first carcass ply (3a), The textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) have a tensile strength that is included in 0.35 cN / Tex to 1.2 cN / Tex with a 2% elongation and in 0.5 cN / Tex to 3 cN / Tex with a 5% elongation. At least one central annular sector (8a) of the tread band (8) arranged across the equatorial plane (X-X) is made of a vulcanized elastomer material having a static modulus of elasticity Ca3 measured at 70°C in the range of 9.0 to 14.0, preferably 10.0 to 13.0, a tandelta measured at 70°C and 10 Hz in the range of 0.120 to 0.160, preferably 0.135 to 0.155, and a dynamic modulus of elasticity E' measured at 70°C and 10 Hz in the range of 3.7 to 4.

1. Motorcycle tire (1).

2. The tire (1) according to claim 1, wherein the central annular sector (8a) of the tread band (8) is made of a vulcanized elastomer material in which the ratio of the tandelta measured at 70°C and 10Hz to the dynamic modulus E' measured at 70°C and 10Hz is 0.03 to 0.

04.

3. The tire (1) according to claim 1, wherein the tread band (8) comprises two lateral annular sectors (8b) positioned on both sides with respect to the equatorial plane (X-X) of the tire and adjacent to the central annular sector (8a); and the central annular sector (8a) is made of a vulcanized elastomer material having a tandelta measured at 70°C and 10Hz that is smaller than the tandelta of the vulcanized elastomer material of the two lateral annular sectors (8b) measured at 70°C and 10Hz.

4. The tire (1) according to claim 3, wherein the central annular sector (8a) is made of a vulcanized elastomer material having a static modulus of elasticity Ca3 measured at 70°C that is greater than the static modulus of elasticity Ca3 measured at 70°C of the vulcanized elastomer material of the two lateral annular sectors (8b).

5. The tire (1) according to claim 3 or 4, wherein the central annular sector (8a) is made of a vulcanized elastomer material having a ratio of tandelta to dynamic modulus E' measured at 70°C and 10Hz that is greater than the ratio of tandelta to dynamic modulus E' measured at 70°C and 10Hz of the vulcanized elastomer material of the two lateral annular sectors (8b).

6. The tire (1) according to claim 1, wherein the central annular sector (8a) has an axial extension having a width greater than 15% of the width of the tread band (8) and less than 30% of the width of the tread band (8).

7. The tire (1) according to claim 1, wherein the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) are made of nylon.

8. The tire (1) according to claim 1, wherein the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) have a linear density in the range of 2000 to 4600 dTex.

9. The tire (1) according to claim 8, wherein the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) have a linear density ranging from 1100 × 2 dTex to 1840 × 2 dTex, and the term "×2" represents the number of ends of yarn twisted together in each reinforcing cord.

10. The tire (1) according to claim 1, wherein the first plurality of textile reinforcing cords and the second plurality of textile reinforcing cords have a thread count that is included in 80 cords / dm to 130 cords / dm.

11. The tire (1) according to claim 1, wherein the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) have a twist applied to each end and to the entire end, forming the textile reinforcing cord which is twisted 30 to 65 times per decimeter.

12. The tire (1) according to claim 1, wherein the predetermined inclination angle (A1) of the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and the second plurality of textile reinforcing cords (32) is in the range of 65° to 90°.

13. The tire (1) according to claim 1, further comprising a belt structure (6) located radially outward from the radial carcass structure (2) and radially inward from the tread band (8).

14. The tire (1) according to claim 13, wherein the belt structure (6) comprises a belt layer (6a) having at least one reinforcing cord (6b) that forms a plurality of windings substantially in the direction of the circumferential direction of the tire.

15. The tire (1) according to claim 1, wherein the tread band (8) has a void / solid ratio contained in 0.4 to 0.65 and has a tread pattern symmetrical with respect to the equatorial plane (X-X) of the tire.

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