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 tire for a motorcycle.

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

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

[0004] This type of motorcycle has a very wide range of uses, from mainly road use, comparable to sport touring, even going as far as supersports, to more extreme off-road use than simple paved roads, such as, for example, all-terrain circuits, so-called dirt tracks, or tracks including river beds, soft ground, mud, sand, and other uneven terrain of various types and difficulties.

[0005] In order to satisfy all these types of use, the market offers different tire products each focused on a clearly defined type of use, e.g. sports driving on open roads, touring driving on open roads, driving on open roads combined with unpaved roads, driving on open roads combined with easy off-road driving, extreme off-road driving combined with open roads.

[0006] Typically, "big enduro" motorcycle tyres, intended primarily for driving on open roads combined with unpaved roads, are approved for a maximum speed of at least 210 km / h (ETRTO speed symbol: H). Such tyres generally have a maximum radial cross-sectional width comprised between 90 and 170 (for example 90-120 for front tyres and 130-170 for rear tyres) and are typically mounted on wheel rims having a mounting diameter comprised between about 17 inches and about 21 inches (for example 19-21 inches for front tyres and 17-18 inches for rear tyres).

[0007] The tire of the present invention is of a type approved for overland use and is intended primarily for overland use in combination with off-road driving, typically primarily for overland use under different load conditions (driver only, driver and luggage, driver and one passenger, driver, one passenger and luggage) and different weather conditions, and, to a minimum, for off-road use. [Background technology]

[0008] "Big enduro" motorcycle tires typically include a tread band having a tread pattern defined by circumferential and transverse grooves at least partially separating a plurality of tread blocks or portions of the tread; such tires typically have a void / solids ratio comprised between about 0.1 and about 0.65. Summary of the Invention

[0009] In this specification and the following claims, all numerical values ​​expressing quantities, parameters, percentages and the like, unless otherwise indicated, are deemed to be preceded in all instances by the term "about." Moreover, all ranges of numerical magnitudes include all possible combinations of maximum and minimum numerical values, all possible intermediate ranges, as well as those specifically set forth below.

[0010] Unless otherwise indicated, all ranges of quantities include both maximum and minimum numerical values.

[0011] Hereinafter, the following definitions apply:

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

[0013] The terms "elastomeric material", "rubber", "elastomeric polymer" or "elastomer" are meant to denote a material comprising a vulcanizable natural or synthetic polymer and a reinforcing filler, such that at room temperature, after vulcanization, such a material can be deformed by a force and can rapidly and forcefully return to substantially its original shape and size after the deforming force is removed (as defined in standard ASTM D1566-11 Standard Terminology for Rubber).

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

[0015] The term "elastomeric compound" is meant to denote a mixture obtainable by mixing, and optionally heating, at least one elastomeric polymer with at least one additive commonly used in the preparation of tire compounds.

[0016] The term "vulcanizable elastomeric compound" is meant to denote an elastomeric mixture ready for vulcanization that can be obtained by incorporating all the additives, including the vulcanization additives, into an elastomeric compound.

[0017] The term "vulcanized elastomeric compound" is meant to denote a material obtainable by vulcanization of a vulcanizable elastomeric compound.

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

[0019] The term "vulcanizing agent" is meant to denote a compound capable of converting natural or synthetic rubber into an elastic and strong material by the formation of a three-dimensional network of intermolecular and intramolecular bonds. Typical vulcanizing agents include elemental sulfur, polymeric sulfur, sulfur donors, such as sulfur-based compounds such as bis[(trialkoxysilyl)propyl] polysulfides, thiurams, dithiodimorpholine, and caprolactam-disulfide.

[0020] The term "vulcanization accelerators" is meant to indicate compounds capable of reducing the duration and / or the operating temperature of the vulcanization process, such as, for example, TBBS, sulfenamides in general, thiazoles, dithiophosphates, dithiocarbamates, guanidines, and sulfur donors, such as thiurams.

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

[0022] The term "vulcanization inhibitor" is meant to denote compounds capable of delaying the initiation of the vulcanization reaction and / or inhibiting undesirable secondary reactions, such as N-(cyclohexylthio)phthalimide (CTP).

[0023] The term "vulcanization package" is meant to refer to a vulcanizing agent and one or more vulcanization additives selected from vulcanization activators, accelerators and retarders.

[0024] The term "reinforcing filler" is meant to denote reinforcing materials typically used in the industry to improve the mechanical properties of tires, preferably selected from carbon black, conventional silica such as silica from sand precipitated with strong acids, preferably amorphous, diatomaceous earth, calcium carbonate, titanium dioxide, talc, alumina, aluminosilicates, 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 and conventional silicates, such as sepiolite, paligorskite, also known as attapulgite, montmorillonite, halloysite, etc., optionally modified by acid treatment and / or derivatization. Typically, white fillers have surface hydroxyl groups.

[0026] The expression "reinforcing cord", or more simply "cord", is meant to denote an elongated element consisting of one or more elongated elements (also called "yarns") coated with or embedded in a matrix of elastomeric material, as the case may be.

[0027] Hereinafter, the expression "yarn" will be used to refer to an elongated element consisting of an assembly of a plurality of textile filaments.

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

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

[0030] A yarn can have one or more "ends," and the term "end" is meant to refer to a bundle of filaments that are twisted together. For example, there can be a single end or at least two ends twisted together.

[0031] Yarns can be identified by a designation representing the textile material, the count of fibers used, and the number of ends that make up the yarn. For example, a yarn with an end made of NY (nylon) identified as NY 1400 x 2 indicates a yarn that includes fibers made of NY with a 1400 dtex count formed from two ends twisted together.

[0032] The term "thread count" of a layer or ply or fabric is meant to indicate the number of reinforcing cords per unit length present in such 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" of a reinforcing cord or yarn are meant to indicate the load and percentage elongation, respectively, at which the reinforcing cord or yarn breaks, evaluated according to BISFA standards, for materials tested according to the definitions set forth below.

[0034] The term "elastic modulus" is meant to indicate the ratio of load (or force) to elongation measured at any point of the load-elongation curve according to the BISFA standard, for a material tested according to the definition given below. Such a curve is drawn by calculating the first derivative of the load-elongation function that defines said curve, normalized to the linear density in Tex. The elastic modulus is therefore expressed in cN / Tex or Mpa. In a load-elongation graph, the elastic modulus is identified by the slope of said curve relative to the X-axis.

[0035] The term "tenacity" of a reinforcing cord or yarn is meant to indicate the calculated ratio between the modulus of elasticity and the linear density. Tensile strength was measured according to BISFA standards, with the material tested according to the definition given below. Tensile strength can be expressed in cN / Tex or cN / dTex.

[0036] For the purposes of the present invention, for the measurement of the linear density and for the determination of the tensile properties, in particular the tensile strength, reference is made to flat threads that are not twisted during the test phase, according to the tests prescribed by the BISFA (Bureau International pour la Standardisation des Fibres Artificielles) standard. 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 relaxation state - paragraph 7.4.1.1 => Preparation of samples on folding reels; 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; Tensile tests performed on a Zwick-Roell Z010 dynamometer For more information, please refer to. - for cords or reinforcing wires of cellulosic materials, e.g. rayon (Ry) or lyocell (LY), see BISFA - Test methods for viscose, cupro, acetate, triacetate and lyocell fibre yarns - 2007 edition Determination of tensile properties: Chapter 7 - Tensile test conditions: Oven dry test - Table 7.1 - Test procedure - Section 7.5 - Tests on specimens in oven relaxation condition - Subsection 7.5.2.4 For more information, please refer to.

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

[0038] The term "curvature ratio" is meant to indicate the ratio of the distance contained in the cross-section of the tire between the radially highest point of the tread band and the tire's radial cross-sectional maximum width (such distance also shown as "arrow") to said maximum width of the tire.

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

[0040] The term "equatorial plane" of a tire is meant to denote the plane perpendicular to the tire's axis of rotation and which bisects the tire symmetrically.

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

[0042] The term "annular sector" is meant to denote a portion of the tread band of a predetermined axial length extending circumferentially around the entire tread band.

[0043] The term "tread pattern" is meant to describe all points of the tread band (including grooves) in a plane perpendicular to the tire's equatorial plane and tangent to its maximum diameter. The tread pattern is defined by a number of blocks, possibly containing recesses, separated by grooves.

[0044] The term "void / solid ratio" is meant to indicate the ratio of the total surface of the grooves of a particular annular portion of the tread pattern of a tire (as the case may be, the entire tread band or the entire tread pattern) to the surface of a particular portion of the tread pattern (as the case may be, the entire tread band or the entire tread pattern).

[0045] The term "footprint" of a tire is meant to indicate that part of the tire that is in contact with the ground or road surface when the tire is mounted on a wheel rim and a predetermined vertical load is applied to the tire.

[0046] The terms "radial" and "axial" as well as the expressions "radially inner / outer" and "axially inner / outer" are used to refer to directions substantially parallel to and substantially perpendicular to the tire's equatorial plane, respectively, i.e., directions substantially perpendicular to and substantially parallel to the tire's pivot axis, respectively.

[0047] The terms "circumferential" and "circumferentially" are used to refer to directions extending circumferentially about the tire, i.e., in the direction of rolling of the tire, which corresponds to directions in a plane coincident with or substantially parallel to the equatorial plane of the tire.

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

[0049] The terms "axially inner" and "axially outer" refer to positions closer to and further from the equatorial plane, respectively, relative to a reference element.

[0050] The term "radial carcass structure" is meant to denote a carcass structure comprising a plurality of reinforcing cords each oriented substantially axially in the crown portion of the tire. Such reinforcing cords may be incorporated in a single carcass ply or in a plurality of carcass plies (preferably two) radially juxtaposed to one another.

[0051] The term "substantially axial" is meant to indicate a direction inclined at an angle comprised between 60° and 90° relative to the equatorial plane of the tire.

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

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

[0054] The term "dynamic mechanical properties" of a tread compound is meant to refer to mechanical properties measured using an Instron Model 1341 dynamic device in tension-compression mode as described herein. Test specimens of crosslinked material (170°C for 15 minutes) having a cylindrical shape (length = 25 mm; diameter = 18 mm) were used, preloaded under compression to a longitudinal deformation of 25% with respect to the initial length, and maintained throughout the test time at predefined temperatures (e.g., 23°C, 70°C, and 100°C). After 125 cycles of mechanical preconditioning at 10 Hz with an amplitude of 7.5% deformation with respect to the length under preload, followed by a waiting period of 2 minutes, the test specimens were subjected to a dynamic sinusoidal stress with an amplitude of ±3.5% with respect to the length under preload at a frequency of 10 Hz. The dynamic mechanical properties are expressed in terms of the values ​​of the dynamic modulus of elasticity (E') and tan delta (loss factor). The tan delta value was calculated as the ratio between the viscous dynamic modulus of elasticity (E'') and the dynamic modulus of elasticity (E').

[0055] The Applicant has realized that, in order to optimally cover its entire range of use, a "big enduro" motorcycle must be fitted with tyres suitable for covering many kilometres and enabling high performance both on the road (mainly stability at high speeds, roadholding, handling in dry and wet conditions) and off-road (mainly traction, controllability and direction keeping).

[0056] However, the applicant has discovered that, due to the current and increasingly prevalent trend towards extreme on-road performance on the one hand, and extreme off-road performance on the other, the aforementioned performance characteristics are at least partially in contrast to one another.

[0057] The applicant has indeed found that tires which enable high performance on the road usually have severe limitations in their off-road performance, and vice versa.

[0058] Applicant has also realized that a tire that provides a good compromise between on-road and off-road use cannot provide satisfactory extreme performance in either of the two environments (on-road and off-road).

[0059] The Applicant has recently noticed that the market foresees many segments of tyres for "big enduro" motorcycles, each such segment moving towards more specialised solutions aligned with customer requirements by focusing on a specific application of the motorcycle.

[0060] The Applicant therefore proposes a "big enduro" motorcycle tyre intended for mainly open road use, i.e. for use on mainly open roads with 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 open roads combined with off-road driving, providing for a minimal use on off-roads.

[0061] Tyres intended primarily for use on roads are designed to maximise performance on tarmac surfaces in terms of stability at high speeds under different load conditions, road holding in dry and wet conditions, handling, fuel economy, traction and braking in wet conditions.

[0062] The Applicant focuses on said segment type tyres for "big enduro" motorcycles, designed primarily for on-road use, chosen by users looking for performance in road driving under various load conditions, but who are expected to make less demanding off-road use.

[0063] The applicant envisaged creating a "big enduro" motorcycle tyre for use primarily on open roads, which would improve performance in terms of stability at high speeds on tarmac and under different load conditions (driver only, driver and luggage, driver and one passenger, driver, one passenger and luggage).

[0064] Motorcycle tyres typically comprise a radial carcass structure extending between a belt structure disposed radially outwardly relative to the carcass structure, optionally consisting of or comprising a bead structure on either side and a zero degree reinforcing layer disposed radially outwardly relative to the carcass structure, and a tread band disposed radially outwardly relative to the belt structure.

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

[0066] The controllability of the motorcycle as perceived by the driver, and therefore the achievable high-speed stability, performance in terms of handling in dry and wet conditions, depends on the grip of the motorcycle under all riding conditions and is therefore related to the footprint area. The stability of the footprint area, i.e. its ability to remain as constant as possible, is imparted by the stiffness of the tire. Within certain limits, the stiffer the tire is, the less it deforms and the faster it recovers from deformations under stress.

[0067] The Applicant has therefore considered using an increase in the stiffness of tyres intended primarily for "big enduro" motorcycles for public roads in order to improve their performance in terms of high-speed stability under different load conditions.

[0068] In order to increase the stiffness of the tire, the applicant has considered increasing the stiffness of the carcass structure.

[0069] A plurality of reinforcing cords are typically provided in the carcass structure to impart structural strength and stiffness properties 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 control.

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

[0072] The Applicant has in fact found that by making the carcass structure of high modulus textile yarns, the stiffness of a tire for a "big enduro" motorcycle is increased and the performance in terms of high speed stability under different load conditions is improved.

[0073] However, the Applicant has realised that this improvement in stability at high speeds under different load conditions is accompanied by a deterioration in handling on both dry and wet surfaces.

[0074] To regain the handling on dry and wet surfaces, the Applicant considered using so-called soft compounds, which adapt better to the roughness of the road surface by transferring its irregular profile to create a tread band. These compounds are typically characterized by low static mechanical properties and high hysteresis properties (regarding the dynamic mechanical properties under compression, in particular tan delta).

[0075] The applicant has realised that the use of a softer 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 and in straight-line driving, particularly at high loads and speeds, i.e. when there are passengers and / or luggage in addition to the driver.

[0077] The Applicant has surprisingly found that by arranging a radial carcass construction comprising two juxtaposed carcass plies with reinforcing cords made from low modulus textile yarns and a tread band with at least one annular sector arranged astride the equatorial plane made of a compound with high static mechanical properties and low hysteresis, it is possible to make a tyre for "big enduro" motorcycles, primarily for use on open roads, with improved performance in terms of high speed stability under various loading conditions, without worsening and in fact surprisingly improving the performance in terms of handling in dry and wet conditions.

[0078] The improvement in the high-speed stability of the tire, as well as the handling performance in dry and wet conditions, is surprising, since a radial carcass structure with reinforcing cords made of low modulus textile yarns, as well as a tread band having at least one annular sector arranged astride the equatorial plane, made from a compound with high static mechanical properties and low hysteresis, does not seem suitable for simultaneously providing high-speed stability under different loading conditions, as well as handling in dry and wet conditions.

[0079] The present invention relates to a motorcycle tire having a radial carcass structure and a tread band applied at a 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 one another in the crown portion of the tread band and have a first inclination at a predetermined inclination angle relative 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 one another in the crown portion of the tread band and have a second inclination at a predetermined inclination angle relative to the equatorial plane of the tire.

[0084] Preferably, the second slope is opposite to the first slope.

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

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

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

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

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

[0090] Preferably, at least one central annular sector of the tread band arranged astride the equatorial plane is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C greater than 9.0.

[0091] Preferably, at least one central annular sector of the tread band arranged astride the equatorial plane is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C of less than 14.0.

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

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

[0094] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta greater than 0.120 measured at 70° C. and 10 Hz.

[0095] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta of less than 0.160 measured at 70° C. and 10 Hz.

[0096] More preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta greater than 0.135 measured at 70° C. and 10 Hz.

[0097] More preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta of less than 0.155 measured at 70° C. and 10 Hz.

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

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

[0100] The Applicant has found through experiments that by using a cross-ply carcass structure and a tread band having the aforementioned characteristics, it is surprisingly possible to improve, without compromising, the dry and wet handling performance of "big enduro" type motorcycle tyres, which are primarily intended for on-road use and do not make many demands on off-road use, and to improve the high-speed stability performance under different load conditions.

[0101] Without being bound by any theory of interpretation, the Applicant believes that the unexpected improvement in high speed stability and dry and wet handling can be at least partially attributed to the fact that an improvement in tire stiffness, and therefore high speed stability under different loading conditions, is obtained by making a radial carcass ply structure having two radially juxtaposed plies and by controlling the static modulus of elasticity at 70°C Ca3 of the central annular sector of the tread band positioned astride the equatorial plane within the aforementioned values, and that dry and wet handling is obtained in such a structure by controlling the tensile strength of the textile reinforcing cords of the carcass ply within the aforementioned values ​​and by controlling the tan delta at 70°C and the dynamic modulus of elasticity at 70°C E' within the aforementioned values.

[0102] Surprisingly, this beneficial technical effect was also observed by using in the carcass ply relatively "low" tensile strength textile reinforcing cords, which are known not to be used to make the tire stiffer, and relatively "low" tan delta values ​​at 70°C (hence limited hysteresis), which are known not to be beneficial to improve handling in dry and wet conditions.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0125] Preferably, the central annular sector of the tread band is made of a vulcanised elastomeric material having a static modulus of elasticity Ca3 measured at 70°C greater than 10.8.

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

[0127] Preferably, the central annular sector of the tread band is made of a vulcanised elastomeric material having a static modulus of elasticity Ca3 measured at 70°C greater than 11.3.

[0128] Preferably, the central annular sector of the tread band is made of a vulcanised elastomeric material having a static modulus of elasticity Ca3 measured at 70°C of less than 12.5.

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

[0130] Preferably, the central annular sector of the tread band is made of a vulcanised elastomeric material having a static modulus of elasticity Ca3 measured at 70°C of less than 11.8.

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

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

[0133] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta greater than 0.140 measured at 70° C. and 10 Hz.

[0134] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta greater than 0.142 measured at 70° C. and 10 Hz.

[0135] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta of less than 0.150 measured at 70° C. and 10 Hz.

[0136] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta of less than 0.148 measured at 70° C. and 10 Hz.

[0137] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta of 0.145 measured at 70° C. and 10 Hz.

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

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

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

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

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

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

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

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

[0146] Preferably, the tread band comprises two lateral annular sectors arranged on either side of the equatorial plane of the tire and adjacent to a central annular sector.

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

[0148] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta measured at 70° C. and 10 Hz that is less than the tan delta measured at 70° C. and 10 Hz of the vulcanized elastomeric materials of the two lateral annular sectors.

[0149] This makes it possible to have a higher hysteresis compound in the shoulders, i.e. the two lateral annular sectors, relative to that in the crown, i.e. the central annular sector, allowing the tire to better adapt to the roughness of the road surface by transferring its irregular profile when cornering.

[0150] Applicant has found that the higher hysteresis in the two lateral annular sectors compared to the central sector does not affect high speed stability under different loading conditions.

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

[0152] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta measured at 70°C and 10 Hz that is greater than a threshold value, the threshold value being equal to 80% of the tan delta of the vulcanized elastomeric material of the lateral annular sectors measured at 70°C and 10 Hz.

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

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

[0155] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta measured at 70°C and 10 Hz that is less than a threshold value, the threshold value being equal to 98% of the tan delta of the vulcanized elastomeric material of the lateral annular sectors measured at 70°C and 10 Hz.

[0156] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta measured at 70°C and 10 Hz that is less than a threshold value, the threshold value being equal to 95% of the tan delta of the vulcanized elastomeric material of the lateral annular sectors measured at 70°C and 10 Hz.

[0157] Preferably, the central annular sector is made of a vulcanized elastomeric material having a tan delta measured at 70° C. and 10 Hz that is equal to 92% of the tan delta of the vulcanized elastomeric material of the lateral annular sectors measured at 70° C. and 10 Hz.

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

[0159] Preferably, the central annular sector is made of a vulcanized elastomeric material having a dynamic elastic modulus E' measured at 70°C and 10 Hz that is less than a threshold value, the threshold value being equal to 115% of the dynamic elastic modulus E' measured at 70°C and 10 Hz of the vulcanized elastomeric materials of the two lateral annular sectors.

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

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

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

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

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

[0165] Preferably, the central annular sector is made of a vulcanized elastomeric material having a ratio of tan delta measured at 70°C and 10 Hz to the dynamic modulus of elasticity E' measured at 70°C and 10 Hz that is less than the ratio of tan delta measured at 70°C and 10 Hz to the dynamic modulus of elasticity E' measured at 70°C and 10 Hz of the two lateral annular sector vulcanized elastomeric materials.

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

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

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

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

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

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

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

[0173] Preferably, the central annular sector is made of a vulcanized elastomeric 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 elastomeric material of the two lateral annular sectors.

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

[0175] The Applicant has noticed that the static modulus measured at 70°C in the lateral annular sectors, in particular Ca3, is not equal to the value of the static modulus in the central annular sector, and that only an increase in the static modulus of the compound in the central annular sector makes it possible to obtain high-speed stability under different loading conditions.

[0176] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is less than a threshold value, the threshold value being equal to 150% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0177] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is less than a threshold value, the threshold value being equal to 140% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0178] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is less than a threshold value, the threshold value being equal to 135% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0179] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is greater than a threshold value, the threshold value being equal to 101% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0180] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is greater than a threshold value, the threshold value being equal to 110% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0181] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is greater than a threshold value, the threshold value being equal to 120% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

[0182] Preferably, the central annular sector is made of a vulcanized elastomeric material having a static elastic modulus Ca3 measured at 70°C that is greater than a threshold value, the threshold value being equal to 125% of the static elastic modulus Ca3 measured at 70°C of the vulcanized elastomeric materials of the two lateral annular sectors.

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

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

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

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

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

[0188] Preferably, the central annular sector has an axial extension of 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 extension of the two lateral annular sectors and of the axial extension of the central annular sector corresponds to the width of the axial extension of the tread band.

[0191] Preferably, the tread band has a void / solid ratio comprised between 0.4 and 0.65.

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

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

[0194] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement 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), rayon fibers.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[0213] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have equal thread counts.

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

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

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

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

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

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

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

[0221] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have equal twists imparted both at each end and throughout the ends forming the textile reinforcement cords, respectively.

[0222] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each of the ends forming the textile reinforcement cords that exceeds 30 twists per decimeter.

[0223] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each of the ends forming the textile reinforcement cords that exceeds 35 twists per decimeter.

[0224] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each end forming the textile reinforcement cord that exceeds 38 twists per decimeter.

[0225] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each end forming the textile reinforcement cord of less than 65 twists per decimeter.

[0226] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each end forming the textile reinforcement cord of less than 55 twists per decimeter.

[0227] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each end forming the textile reinforcement cord of less than 45 twists per decimeter.

[0228] Preferably, the textile reinforcement cords of the first plurality of textile reinforcement cords and the second plurality of textile reinforcement cords have a twist imparted to each end and across each of the ends forming the textile reinforcement cords forming 40 twists per decimeter.

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

[0230] Preferably, the first carcass ply and the second carcass ply are comprised of respective sheets of elastomeric material incorporating a first plurality of textile reinforcing cords and a second plurality of textile reinforcing cords, respectively.

[0231] Preferably, the belt structure is provided radially outer relative to the radial carcass structure and radially inner relative to the tread band.

[0232] Preferably, the belt structure comprises a belt layer comprising at least one reinforcing cord forming a plurality of turns oriented substantially according to the circumferential direction of the tire.

[0233] Preferably, the belt layer comprises a reinforcing ribbon-like element of rubberized fabric including a plurality of axially aligned reinforcing cords forming a plurality of turns oriented substantially along the circumferential direction of the tire.

[0234] Preferably, the plurality of turns are inclined at an angle comprised between 0° and 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 content steel, the carbon content being at least 0.6% by weight.

[0237] Preferably, the carcass reinforcing structure is made of an elastomeric material disposed radially between the radial carcass structure and the belt structure.

[0238] Preferably, the carcass reinforcing structure made of elastomeric material extends axially over a surface that substantially corresponds to the surface of the extension of the belt structure.

[0239] Further features and advantages of the tire of the present invention will become more apparent from the following detailed description of preferred embodiments thereof, which proceeds with reference to the accompanying drawings. [Brief description of the drawings]

[0240] [Figure 1] 1 is a schematic perspective view in radial section of a motorcycle tyre according to the invention, the grooves and blocks of the tread band not being shown for ease of illustration; FIG. [Figure 1A] 2 is a schematic perspective view of a further radial section of a motorcycle tyre according to the invention, the grooves and blocks of the tread band being not shown for ease of illustration; [Diagram 2] 1 is a schematic view of a radial section of a motorcycle tire according to the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0242] The tire 1 shown is a rear tire, but the following description applies equally to front tires, except when specific reference is made to rear tires.

[0243] Tire 1 is a high displacement tire (e.g. 1000 cm 3 The tire is for motorcycles defined as "big enduro" having a mass of, for example, 200 kg or more in a riding configuration, with a torque of, for example, 100 cv, and high power (for example, equal to 100 cv).

[0244] The tire 1 generally has a maximum radial cross-sectional width comprised between 90 and 170 (e.g., between 90 and 120 for a front tire and between 130 and 170 for a rear tire) and is intended to be mounted on a wheel rim having a mounting diameter comprised between about 17 inches and about 21 inches (e.g., between 19 and 21 inches for a front tire and between 17 and 18 inches for a rear tire).

[0245] An equatorial plane "XX" and a rotation axis R (not shown) are defined on the tire 1. A circumferential direction arranged according to the direction of rotation of the tire 1 and thus 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 are also defined.

[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 3 a comprises a sheet of elastomeric material incorporating a first plurality of textile reinforcing cords 30 .

[0248] The second carcass ply 3 b comprises a sheet of elastomeric material incorporating a second plurality of textile reinforcing cords 32 .

[0249] The elastomeric material making up the sheet of elastomeric material of the first carcass ply 3a is the same as the elastomeric material making up the sheet of elastomeric material of the second carcass ply 3a.

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

[0251] In one embodiment, the second ply of the carcass 3 b is made by bonding together a plurality of strips of elastomeric 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 one another and are oriented substantially axially. The textile reinforcing cords 31 of the first plurality of textile reinforcing cords 30 have a first inclination with a predetermined inclination angle A1 relative to the equatorial plane XX of the tire in the crown portion 8C of the tread band. Each textile reinforcing cord 31 of the first plurality of textile reinforcing cords 30 belongs to a respective radial plane of the tire 1.

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

[0254] Such a predetermined inclination angle A1 is included in an absolute value of 65° to 90° with respect to the circumferential direction. The first inclination is opposite 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 a first angular direction with respect to the circumferential direction, and the predetermined inclination angle A1 of the second inclination is measured along a second angular direction with respect to the circumferential direction, and the first angular direction and the second angular direction are opposite to each other.

[0255] In a preferred embodiment of the present invention, the predetermined tilt angle A1 has an absolute value of about 70°.

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

[0257] The textile reinforcement cords 31, 33 of the first plurality of textile reinforcement cords 30 and the second plurality 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", consisting essentially of an airtight layer of elastomeric 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 conform substantially to a toroidal form, as best shown in Figure 1, and have respective axially opposed side edges 3c, 3d which are turned up at respective annular reinforcing structures 4. The annular reinforcing structures 4 are intended to retain the tire 1 on a corresponding mounting rim (not shown). The annular reinforcing structures 4 are typically referred to as "bead cores."

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

[0261] In an alternative embodiment, not shown, the first carcass ply 3a and the second carcass ply 3b may have opposite side edges 3c, 3d which are not turned up and are associated with a specific annular reinforcing structure with two metal annular inserts.

[0262] The area of ​​the tire 1 comprising the bead core 4 and the elastomeric filling 5 forms a so-called bead 9, which is intended to fix the tire 1 to a rim, not shown.

[0263] The tire 1 comprises a pair of sidewalls 7 applied laterally on either side of a radial carcass structure 2 .

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

[0265] The flipper 12 is a reinforcing layer wrapped around and at least partially surrounding each of the bead wires 4 and the elastomeric filler material 5. Such a reinforcing layer is disposed between the radial carcass structure 2 and the beads 9.

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

[0267] In a possible preferred embodiment, the bead 9 may be provided with a further protective layer 13 (shown in FIG. 2, not shown in FIG. 1), commonly known as a "chafer" or protective strip, which has the function of increasing the rigidity and integrity of the bead 9.

[0268] In a preferred embodiment, the carcass reinforcing structure 11 is provided at a radially outer position with respect to the radial carcass structure 2. Such a carcass reinforcing structure 11 comprises a crown ply 11a arranged at a radially outer position with respect to the second carcass ply 3b and in at least one crown portion of the second carcass ply 3b.

[0269] The crown ply 11a comprises reinforcing elements arranged parallel to one another. The crown ply 11a is arranged on the second carcass ply 3b such that the reinforcing elements of the crown ply 11a have an opposite angle relative to the equatorial plane to the reinforcing elements of the second carcass ply 3b. Optionally, the carcass reinforcing structure 11 also comprises two plies (not shown) arranged on either side of the crown ply 11a and not associated with the respective beads.

[0270] A belt structure 6 (shown in FIG. 2) is applied circumferentially at a radially outer location relative to the radial carcass structure 2 .

[0271] The belt structure 6 comprises a belt layer 6a comprising at least one reinforcing cord 6b forming a plurality of turns.

[0272] Preferably, the belt structure 6 is of the zero degree type, i.e. the belt layer 6a is made of reinforcing cords 6b arranged substantially parallel side-by-side to form a number of turns, the orientation of such turns being substantially circumferential (typically at an angle between 0° and 5°), such an orientation being usually referred to as "zero degree" with reference to how it is positioned with respect to the circumferential direction of the tire 1.

[0273] Preferably, the belt layer 6a comprises axially aligned windings of ribbon-like reinforcing elements of rubberized fabric comprising a plurality of axially aligned reinforcing cords 6b forming a plurality of turns oriented substantially according to the circumferential direction of the tire 1.

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

[0275] Preferably, the windings defined by the turns 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 cords 6b of the belt layer 6a are made of metal, that is, steel wires having a high carbon content, i.e., a carbon content of at least 0.6 to 0.7% by weight. Preferably, such metal cords have high elongation (HE).

[0277] The belt structure 6 has thereon a circumferentially juxtaposed tread band 8 which, after a moulding operation carried out simultaneously with the vulcanisation step of the tyre 1, is typically formed with circumferential and transverse grooves 10 arranged to define the boundaries of a number of blocks.

[0278] Referring to FIG. 1, the tire 1 has a section height "H" measured at the equatorial plane "XX" between the top of the tread band 8 and a mounting diameter identified by a reference line "r" passing through the bead 9 of the tire 1.

[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 may be formed with edges.

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

[0281] The tire 1 has an "arrow to total height" ratio (f / H) given by the ratio of the arrow "f" to the section height "H".

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

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

[0284] The tire 1 has a curvature ratio "f / C" comprised between about 0.25 and about 0.35, for example equal to about 0.26.

[0285] The tire 1 has a ratio "f / H" of the arrow to the overall height comprised between about 0.40 and about 0.60, for example "f / H" equal to about 0.43.

[0286] For the front tire, the arrow "f" is comprised between about 35 mm and about 60 mm, and the curvature ratio "f / C" is comprised between about 0.30 and about 0.40, for example equal to 0.38.

[0287] Also, in the case of the front tire, the ratio of the arrow to the overall height "f / H" is included in the range of about 0.40 to about 0.60, and is, for example, equal to about 0.53.

[0288] 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 incorporated in the first carcass ply 3a and the second carcass ply 3b, respectively, have a tensile strength of greater than 0.52 cN / Tex at 2% elongation.

[0289] 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 incorporated in 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 textile reinforcement cords 31, 33 of first plurality of textile reinforcement cords 30 and 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 at 5% elongation of less than 1.2 cN / Tex.

[0293] 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 tensile strength of 1 cN / Tex at 5% elongation.

[0294] A preferred material for making 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 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 of less than 3000 dTex.

[0297] 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 2800 dTex.

[0298] In a preferred embodiment of the 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 1300 x 2 dTex, where the term x 2 represents the number of yarn ends twisted together in each reinforcement cord.

[0299] In a preferred embodiment of the 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 of less than 1500 x2 dTex, where the term x2 represents the number of yarn ends twisted together in each reinforcement 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 x 2 dTex, where the term x 2 represents the number of yarn ends twisted together in each reinforcement cord.

[0301] 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 thread count greater than 105 cords / dm.

[0302] 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 thread count of less than 120 cords / dm.

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

[0304] In a preferred embodiment of the 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 twist imparted at each end and across the ends forming the textile reinforcement cords, respectively, that forms greater than 38 and greater than 42 twists per decimeter.

[0305] In a preferred embodiment of the 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 twist imparted to each end and across the ends forming the textile reinforcement cords, respectively, of less than 42 twists per decimeter.

[0306] 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 twist imparted to each end and throughout the ends forming the textile reinforcement cords, respectively, of less than 40 twists per decimeter.

[0307] The tread band 8 comprises at least one central annular sector 8a (illustrated in FIG. 2) made of elastomeric material and arranged astride the equatorial plane XX.

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

[0309] In a preferred embodiment of the invention, the tread band 8 has, in addition to a central annular sector 8a, two lateral annular sectors 8b arranged symmetrically on either side relative 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 elastomeric material different from the elastomeric material from which the central annular sector 8a is made.

[0311] The central annular sector 8 a has an axial extension whose width is greater than 18% of the width of the tread band 8 .

[0312] The central annular sector 8 a has an axial extension whose width is less than 26% of the width of the tread band 8 .

[0313] In a preferred embodiment of the invention, the central annular sector 8a has an axial extension whose width is greater than 20 percent of the width of the tread band.

[0314] In a preferred embodiment of the invention, the central annular sector 8a has an axial extension of less than 24% of its width.

[0315] For example, the central annular sector 8 a has an axial extension whose width is equal to 22% of the width of the tread band 8 .

[0316] The two lateral annular sectors 8b are arranged, at a respective distance along their axial extension, relative to the equatorial plane XX which is 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 8 b and the axial extension of the central annular sector 8 a corresponds to the width of the axial extension of the tread band 8 .

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

[0320] In particular, for the tread compounds of the lateral annular sectors 8b and the central annular sector 8a, it is possible to use elastomer compositions comprising at least one diene elastomeric polymer chosen, for example, from diene elastomeric polymers commonly used in sulphur crosslinkable elastomeric compositions (vulcanized), peroxide or other systems known to those skilled in the art and particularly suitable for tire production, or from elastomeric polymers or copolymers having unsaturated chains, usually having a glass transition temperature (Tg) below 20°C, preferably in the range from 0°C to -110°C.

[0321] Preferably, the tread compound of the lateral annular sector 8b and the central annular sector 8a comprises 100 phr of at least one diene elastomeric polymer, including at least one styrene-butadiene rubber (dry polymer) selected from solution styrene-butadiene rubber (S-SBR), emulsion styrene-butadiene rubber (E-SBR) or mixtures thereof, in an amount comprised between 50 and 90 phr.

[0322] Commercially available examples of 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 compound of the lateral annular sector 8b and the central annular sector 8a comprises 10 to 50 phr of at least one butadiene polymer (BR), preferably a low cis functionalized BR.

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

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

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

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

[0328] Examples of commercially available terpene-based natural resins include Piccolyte F90 and Piccolyte F105 resins 2495 manufactured by PINOVA; Dercolyte A 115 and Dercolyte M 115 manufactured by DRT.

[0329] At least one resin can be a hydrocarbon.

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

[0331] Specific examples of commercially available hydrocarbon resins include NOVARES C resins (synthetic indene-coumarone resins) manufactured by RUTGERS CHEMICAL GmbH, with NOVARES C10, C30 and C90 being particularly preferred.

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

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

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

[0335] The term "plasticizing oil" is meant to denote a processing oil derived from petroleum or mineral oil, or an oil of vegetable or synthetic origin, or a combination thereof.

[0336] The plasticizing oil may be a petroleum derived process oil selected from paraffins (saturated hydrocarbons), naphthenes, polycyclic aromatics, and mixtures thereof.

[0337] Examples of suitable 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), as known in the industry.

[0338] The plasticizing oil may be an oil of natural or synthetic origin derived from the esterification of glycerol with fatty acids, including triglycerides, diglycerides, monoglycerides of glycerin or mixtures thereof.

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

[0340] An example of an oil used in the compound is tri-(2-ethylhexyl)-phosphate (TOF), Lanxess.

[0341] The plasticizing oil may be a synthetic oil selected from alkyl or aryl esters of phthalic or phosphoric acids.

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

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

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

[0345] The elastomeric composition for tires according to the invention may comprise at least 20 phr, preferably at least 30 phr, more preferably at least 40 phr, and even more preferably at least 50 phr of at least one reinforcing filler.

[0346] The composition may comprise from 10 phr to 150 phr, from 30 phr to 120 phr of at least one reinforcing filler.

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

[0348] In certain embodiments, the reinforcing filler is a white filler selected from hydroxides, oxides and hydrated oxides, salts and hydrated salts of metals, silicate fibers, or mixtures thereof. Preferably, the white filler is silica.

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

[0350] Commercially available examples of suitable conventional silicas include Zeosil 1165 MP from Solvay, and Ultrasil 7000 GR from Evonik.

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

[0352] Preferably, carbon black is present in the elastomeric composition in an amount comprised between 1 phr and 100 phr, more preferably between 5 phr and 70 phr.

[0353] Preferably, carbon blacks are selected from those having a surface area (determined by statistical thickness specific surface area according to STSA-ISO 18852:2005) of at least 20 m2 / g, preferably greater than 50 m2 / g.

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

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

[0356] Elastomeric compositions for tire compounds preferably contain at least 0.7 phr, more preferably at least 1 phr, of at least one vulcanizing agent.

[0357] Elastomer compositions for tire compounds preferably contain 0.5 to 7 phr, more preferably 1 to 5 phr, of vulcanizing agent.

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

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

[0360] Commercially available examples of vulcanizing agents suitable for use in the elastomeric compositions of the present invention are Rhenocure® IS90P manufactured by RheinChemie or Redball Superfine sulfur manufactured by International Sulphur Inc.

[0361] In the present elastomeric compounds, the vulcanizing agents may be used together with adjuvants such as vulcanization activators, accelerators and / or retarders known to those skilled in the art.

[0362] The elastomeric compound may optionally include at least one vulcanization activator.

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

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

[0365] A preferred active agent is derived from the reaction of zinc oxide and stearic acid.

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

[0367] The elastomeric compound may further comprise at least one vulcanization accelerator.

[0368] The primary and secondary accelerators may generally be selected from, for example, dithiocarbamates, guanidines, thioureas, thiazoles, sulfenamides, sulfenimides, thiurams, amines, xanthates, 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] Commercially available examples of accelerators suitable for use in the present elastomeric compounds include Vulkacit® N-cyclohexyl-2-benzothiazolylsulfenamide (CBS or CZ) sold by Lanxess, and N-tertbutyl 2-benzothiazylsulfenamide, Vulkacit® NZ / EGC, tetrabenzyl thiuram disulfide (Perkacit® TBzTD), dibenzothiazole disulfide Rhenogran MBTS 80, N-tert-butyl-2-benzothiazylsulfenamide from Huatai Chemicals TBBS.

[0371] The vulcanization accelerator may be used in the present elastomeric compound in an amount of preferably 0.05 phr to 10 phr, preferably 0.1 phr to 7 phr, more preferably 0.5 phr to 5 phr.

[0372] The elastomeric compound may optionally include at least one vulcanization inhibitor.

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

[0374] A commercially available example of a suitable inhibitor is N-cyclohexylthiophthalimide VULKALENT G manufactured by Lanxess.

[0375] Vulcanization inhibitors may be present in the elastomeric compound, preferably in an amount of from 0.05 phr to 2 phr.

[0376] The elastomeric compound may contain in the mixture one or more vulcanization inhibitors as defined above.

[0377] The elastomeric compound may further comprise at least 0.05 phr, preferably at least 0.1 phr or 0.5 phr, more preferably at least 1 phr or 2 phr of at least one silane coupling agent.

[0378] Preferably, the elastomeric compound comprises 0.5 phr to 10.0 phr, more preferably 1.0 phr to 8.0 phr, even more preferably 5 to 8 phr of at least one silane coupling agent.

[0379] Preferably, the coupling agent is a silane coupling agent selected from those having at least one hydrolyzable silane group, which is, for example, represented by the following general formula (III): (R')3Si-CnH2n-X (III) wherein the R' groups, which may be the same or different, are selected from among alkyl, alkoxy or aryloxy groups, or halogen atoms, with the proviso 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', m and n are integers from 1 to 6, and the R' groups are defined as above. It can be identified by:

[0380] Particularly preferred silane coupling agents are bis(3-triethoxysilyl-propyl) tetrasulfide and bis(3-triethoxysilyl-propyl) disulfide. The coupling agents can be added neat or in admixture with inert fillers (e.g., carbon black) to facilitate their incorporation into the elastomeric compound.

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

[0382] The elastomeric compound may further comprise one or more additional ingredients commonly used in the industry, such as antioxidants and / or antiozonants (antidegradants), waxes, adhesives, and the like.

[0383] The elastomeric compound may optionally include at least one wax.

[0384] For example, the wax may be a mixture of petroleum waxes or paraffins.

[0385] Commercially available examples of suitable waxes include N-Paraffin from Repsol and Antilux® 654 microcrystalline cellulose wax from Rhein Chemie.

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

[0387] The elastomeric compound may optionally include at least one antioxidant.

[0388] The antioxidant is 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), N,N'-ditolyl-p-phenylenediamine (DPPD), N,N'-diisopropyl-N' ... Preferably, the diphenylenediamine is selected from N-1,3-dimethylbutyl-N-phenyl-p-phenylenediamine (6-PPD), N,N'-di-beta-naphthyl-p-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 the like, and mixtures thereof, and preferably, it is N-1,3-dimethylbutyl-N-phenyl-p-phenylenediamine (6-PPD).

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

[0390] Antioxidants may be present in the elastomeric composition in a total amount preferably from 0.1 phr to 20 phr, preferably from 0.5 phr to 10 phr.

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

[0392] In a preferred embodiment of the invention, the elastomeric material of the central annular sector 8a of the tread band 8 is selected in such a way that the final (vulcanized) tire has, in the central annular sector 8a, a static modulus of elasticity Ca3, measured at 70 ° C, comprised between 9.0 and 14.0, a tan delta 8a, 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.

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

[0394] Preferably, the elastomeric material of the central annular sector 8a of the tread band 8 is selected so that the finished (vulcanized) tire has, in the central annular sector 8a, a static modulus of elasticity Ca3, measured at 70°C, of ​​less than 11.9.

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

[0396] Preferably, the elastomeric material of the central annular sector 8a of the tread band 8 is selected so that the finished (vulcanized) tire has, in the central annular sector 8a, a tan delta greater than 0.138 measured at 70° C. and 10 Hz.

[0397] Preferably, the elastomeric material of the central annular sector 8a of the tread band 8 is selected so that the finished (vulcanized) tire has, in the central annular sector 8a, a tan delta measured at 70° C. and 10 Hz of less than 0.152.

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

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

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

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

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

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

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

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

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

[0407] The elastomeric material of the central annular sector 8a of the tread band 8 is selected so that the final (vulcanized) tire has, in the central annular sector 8a, a static modulus of elasticity C3 measured at 70°C that is greater than the static modulus of elasticity C3 measured at 70°C of the vulcanized elastomeric material of the two lateral annular sectors 8b.

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

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

[0410] For example, the elastomeric material of the central annular sector 8a of the tread band 8 is selected so that the final (vulcanized) tire has, in the central annular sector 8a, a static modulus of elasticity C3 measured at 70°C that is equal to 130% of the static modulus of elasticity C3 measured at 70°C of the vulcanized elastomeric material of the lateral annular sectors 8b.

[0411] Comparative Test The Applicant has produced a sample of a rear tire 1 according to an embodiment of the invention, hereinafter such a tire will be designated INV.

[0412] The tyre INV had the same dimensions as the Applicant's rear tyres for motorcycles currently on the market, intended primarily for road use and with limited off-road use, hereinafter such tyres will be designated Ref.

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

[0414] The two tires had the properties shown in Table 1 for the carcass construction.

[0415] [Table 1]

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

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

[0418] The elastomer compositions used to make the vulcanized elastomeric material of the central annular sector of the two tires are shown in Table 2.

[0419] [Table 2] S-SBR: Solution polymerized styrene-butadiene rubber, extended with 37.5 parts TDAE oil per 100 parts dry polymer (110 phr extended polymer is equivalent to 80 phr dry polymer, 96.2 phr extended polymer is equivalent to 70 phr dry polymer, 100.4 phr extended polymer is equivalent to 73 phr dry polymer), Tufdene E680, Asahi Kasei. Functionalized BR: Low cis functionalized polybutadiene YB03, Asahi Kasei BR: High cis polybutadiene from solution EUROPRENE NEOCIS BR 60, 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 Extracts, 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 Resins: 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®-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® IS 90 P (RheinChemie) TBBS: N-tert-butyl-2-benzothiazolesulfenamide from Huatai Chemicals MBTS 80: Rhenogran MBTS 80 dibenzothiazole disulfide, Rhein Chemie TBzTD: Tetrabenzyl thiuram disulfide (Perkacit® TBZTD) DPG 80: N,N'-diphenylguanidine accelerator Rhenogran® RheinChemie PVI N-Cyclohexylthiophthalimide manufactured by Brenntag Spa, Milan, Italy.

[0420] Table 3 below shows the results of static and dynamic mechanical analyses carried out on samples of the vulcanized elastomeric materials used in the central annular sector of tires according to the invention and comparative tires, obtained by vulcanizing the elastomeric compositions shown in Table 2 above.

[0421] The elastomeric materials were obtained by vulcanizing the elastomeric compositions shown in Table 2 above at 170° C. for 15 minutes.

[0422] [Table 3]

[0423] As can be seen from table 3 above, the elastomeric material used in the central annular sector of the tire according to the invention has a static stiffness under deformation that is 300% higher than the corresponding static stiffness of the elastomeric material used in the central annular sector of the comparative tire: according to the applicant, this property may be a predictor of high running stability. The elastomeric material used in the central annular sector of the tire according to the invention has a dynamic modulus of elasticity at 70 ° C that is slightly higher than that of the comparative tire at 70 ° C, and a significantly lower tan delta, with the result that the tan delta / E' ratio, which may be correlated to a parameter indicator of the grip of the tire, is lower with respect to the tan delta / E' ratio of the elastomeric material used in the central annular sector of the comparative tire. Such a low value of the tan delta / E' ratio of the crown portion of the tread band of the tire according to the invention should be a predictor of a deterioration of the grip performance of the tire. Surprisingly, the running tests carried out (as described below) instead produced results opposite to those expected.

[0424] Outdoor comparison tests were conducted using the Ref tire, which is highly rated by customers for its excellent on-road behavior and more than acceptable off-road behavior.

[0425] The tests were carried out under identical environmental conditions, in particular at temperatures between 10°C and 40°C for tests on dry asphalt and 10°C and 20°C for tests on wet asphalt, with both tyres (pressurised to the same tyre pressure of 2.9 bar) mounted on the rear wheel of a BMW R1250 GS motorcycle and an identical tyre mounted on the front wheel.

[0426] The behavior of the two tyres INV and Ref was evaluated by the drivers on both road (dry and wet) and non-extreme off-road conditions. In particular, the items listed in table 4 below were evaluated and the opinions expressed by the drivers are also given.

[0427] Road tests were carried out by driving on both dry and wet roads, in straight and curved sections.

[0428] In Table 4, "=" indicates a positive rating 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 performance on the road, especially in terms of stability and handling in dry and wet conditions, compared to the performance of the Ref tire.

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

[0432] The Applicant has therefore determined that by using a cross-ply carcass structure and tread band with adapted characteristics in the tire of the present invention, it has in fact been possible to achieve a highly desirable improvement in stability at high speeds relative to the road surface, without compromising, and in fact surprisingly improving, handling in dry and wet conditions.

[0433] Of course, a person skilled in the art may make further modifications and variations to the above tire 1 to meet specific and temporary application requirements, and these modifications and variations shall in any case fall within the scope of protection as defined by the following claims.

Claims

1. A tire (1) for a motorcycle comprising a radial carcass structure (2) and a tread band (8) applied in a radially outer position relative to the radial carcass structure (2), 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 reinforcement cords (31) of the first plurality of textile reinforcement cords (30) are substantially parallel to one another and have, in the crown portion (8c) of the tread band (8), a first inclination with respect to the equatorial plane (X-X) of the tire at a predetermined inclination angle (A1); the textile reinforcement cords (33) of the second plurality of textile reinforcement cords (32) are substantially parallel to one another and have, in the crown portion (8c) of the tread band (8), a second inclination with respect to the equatorial plane (X-X) of the tire at the predetermined inclination angle (A1), said second inclination being opposite to said first inclination; The second carcass ply (3b) is radially juxtaposed on the first carcass ply (3a); said textile reinforcement cords (31, 33) of said first plurality of textile reinforcement cords (30) and said second plurality of textile reinforcement cords (32) have a tensile strength comprised between 0.35 cN / Tex and 1.2 cN / Tex at 2% elongation and between 0.5 cN / Tex and 3 cN / Tex at 5% elongation; at least one central annular sector (8a) of said tread band (8) arranged astride said equatorial plane (X-X) 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, preferably between 10.0 and 13.0, a tan delta measured at 70°C and 10 Hz comprised between 0.120 and 0.160, preferably between 0.135 and 0.155, and a dynamic modulus of elasticity E' measured at 70°C and 10 Hz comprised between 3.7 and 4.1, A tire for a motorcycle (1).

2. Tyre (1) according to claim 1, wherein said central annular sector (8a) of said tread band (8) is made of a vulcanised elastomeric material for which the ratio between tan delta, measured at 70°C and 10 Hz, and the dynamic modulus of elasticity E', measured at 70°C and 10 Hz, is comprised between 0.03 and 0.

04.

3. 3. Tyre (1) according to claim 1 or 2, wherein the tread band (8) comprises two lateral annular sectors (8b) arranged on either side with respect to the equatorial plane (X-X) of the tyre and adjacent to the central annular sector (8a); and the central annular sector (8a) is made of a vulcanised elastomeric material having a tan delta measured at 70°C and 10 Hz that is smaller than the tan delta measured at 70°C and 10 Hz of the vulcanised elastomeric material of the two lateral annular sectors (8b).

4. 4. Tyre (1) according to claim 3, wherein said central annular sector (8a) is made of a vulcanized elastomeric 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 elastomeric material of said two lateral annular sectors (8b).

5. 5. Tyre (1) according to claim 3 or 4, wherein said central annular sector (8a) is made of a vulcanised elastomeric material having a ratio between tan delta, measured at 70°C and 10 Hz, and a Dynamic Modulus of Elasticity E', measured at 70°C and 10 Hz, which is greater than the ratio between tan delta, measured at 70°C and 10 Hz, and a Dynamic Modulus of Elasticity E', measured at 70°C and 10 Hz, of the vulcanised elastomeric material of said two lateral annular sectors (8b).

6. 6. Tyre (1) according to any one of the preceding claims, wherein said central annular sector (8a) has an axial extension of a width greater than 15% of the width of said tread band (8) and less than 30% of the width of said tread band (8).

7. 7. Tyre (1) according to any one of claims 1 to 6, wherein the textile reinforcement cords (31, 33) of the first plurality of textile reinforcement cords (30) and the second plurality of textile reinforcement cords (32) are made of nylon.

8. Tyre (1) according to any one of claims 1 to 7, wherein the textile reinforcing cords (31, 33) of the first plurality of textile reinforcing cords (30) and of the second plurality of textile reinforcing cords (32) have a linear density comprised between 2000 and 4600 dTex.

9. 9. Tire (1) according to claim 8, wherein said textile reinforcement cords (31, 33) of said first plurality of textile reinforcement cords (30) and said second plurality of textile reinforcement cords (32) have a linear density comprised between 1100x2 dTex and 1840x2 dTex, the term "x2" representing the number of yarn ends twisted together in each reinforcement cord.

10. 10. Tire (1) according to any one of claims 1 to 9, wherein the textile reinforcement cords of the first plurality of textile reinforcement cords and of the second plurality of textile reinforcement cords have a thread count comprised between 80 cords / dm and 130 cords / dm.

11. 11. The tire (1) according to any one of claims 1 to 10, wherein 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 twist imparted at each end and across the ends respectively, forming the textile reinforcement cords twisted between 30 and 65 turns per decimeter.

12. 12. Tyre (1) according to any one of claims 1 to 11, wherein the predetermined inclination angle (A1) of the textile reinforcement cords (31, 33) of the first plurality of textile reinforcement cords (30) and of the second plurality of textile reinforcement cords (32) is comprised between 65° and 90°.

13. 13. Tyre (1) according to any one of the preceding claims, comprising a belt structure (6) in a radially outer position relative to said radial carcass structure (2) and in a radially inner position relative to said tread band (8).

14. Tyre (1) according to claim 13, wherein the belt structure (6) comprises a belt layer (6a) comprising at least one reinforcing cord (6b) forming a plurality of turns oriented substantially according to the circumferential direction of the tyre.

15. Tyre (1) according to any one of the preceding claims, wherein said tread band (8) has a voids / solids ratio comprised between 0.4 and 0.65 and has a tread pattern symmetrical relative to the equatorial plane (X-X) of the tyre.

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