Abstract: A pneumatic tire according to the present invention includes a tread surface having a tire rotation direction designated in one direction. The tread surface has a straight main groove extending in a circumferential direction of the tire in the center, and lateral grooves obliquely extending in a width direction of the tire on both sides thereof, defining blocks thereon. On both sides of the straight main groove, left and right slant main grooves are arranged to cross three or more lateral grooves. Both ends of-the slant main grooves are positioned within the blocks, and the groove width thereof is gradually enlarged from both end portions toward the center portion of the slant main groove. The inclination angle of the slant main grooves relative to the tire circumferential direction is set in a range of 10 to 45°, and the maximum groove width thereof is set to 80 to 110% of the groove width of the straight main groove.

Abstract: An All Terrain Vehicle Tire (10) for the drive axle positions has a tread (12) having three circumferentially continuous channels (61 62, 63). Two of the channels (62, 63) divide the elongated lugs (40, 42) into an axially inner portion (40A, 42A) and an axially outer portion (40B, 42B). The channels (61, 62, 63) and soil discharge channels (60) between elongated lugs (40, 42) facilitate mud cleaning of the tread (12).

Abstract: A tire for vehicle wheels provided with a tread pattern includes at least one continuous central circumferential groove straddling an equatorial plane of the tire, at least two continuous lateral circumferential grooves having median planes substantially parallel to the equatorial plane of the tire, and a plurality of transverse grooves. These grooves delimit at least four circumferential rows of blocks, two central rows and two shoulder rows. Each block of the central rows is defined by a plurality of sides and at least four vertices, a pair of front vertices and a pair of rear vertices, in relation to a predetermined running direction of the tire. The blocks of the central rows include a first transverse notch having a first terminal end inside a respective block of the central rows and a first starting end communicating with the at least one central circumferential groove.

Abstract: A pneumatic tire comprises a tread portion having a plurality of slant grooves, in which each slant groove has a steeply slant groove portion and a gently slant groove portion, and the steeply slant groove portion comprises a pseudo-land part of a given shape, and can improve a drainage performance without sacrificing the other tire performances.

Abstract: A pneumatic radial tire for all-season passenger car comprises a tread with a tread block pattern defined by plural slant grooves and at least one circumferential center groove and consisting of a central zone having a width corresponding to 30-60% of a tread width and a pair of side zones located on both sides of the central zone, wherein the slant grooves comprise steeply slant grooves and gently slant grooves each having a given shape, and the number of the gently slant grooves is made two times or more than the number of the steeply slant grooves, and the block is provided with at least one sipe, and each of the blocks defined by the circumferential center groove and the steeply slant grooves is chamfered from a tapered top end over a given range toward a longitudinal direction of the block.

Abstract: The invention relates to pattern blocks in the tread of a vehicle tire, the tread comprising the tread layer (20) on the tire carcass (25) and on that pattern blocks (1) separated from each other by wider grooves (21). At least part of these pattern blocks comprise fine slits (2), which are substantially narrower than the grooves, each slit comprising within the area (A1) of the pattern block at least one bend (5) or at least one end (4). Two adjacent slits (2) form surface tear points (10), each of which is formed of: webs (3a, 3b) between at least one end (4) of one slit and at least one second slit or its end; or webs (3c, 3d) between the bend of one slit and one second slit or its bend (5). The web width (W2) of the webs is at most five times the slit width (W2), and the adjacent slits restrict between their mutual webs (3a-3d) between them nubs (8) inside the pattern block.

Abstract: A pneumatic tire in which a sipe, which is substantially parallel to a contour line of a trailing edge of a ground-contact configuration, is formed in a trailing edge region of each block at shoulder sides of the pneumatic tire. From a time of step-in to a time of kick-out of a block, the effect of shearing strain which is transmitted to a trailing edge from a preceding trailing edge portion is mitigated, and movement of the trailing edge of the block with respect to a road surface is suppressed. Accordingly, wear at the trailing edge of the block, i.e., heel-and-toe wear, is suppressed, and noise caused by heel-and-toe wear is reduced.

Abstract: A tire tread for a pneumatic tire has a center rib and a series of steeply slanted grooves in each side region of the tread, the circumferentially adjacent grooves form blocks extending through the tread side regions. The center rib has a serrated configuration along each lateral side and a supporting chamfer extending from each serration point. Adjacent to each rib chamfer is a chamfer extending from the axially innermost point of the rib at the junction of two adjacent steeply slanted grooves. The rib is provided with high density siping. The tread blocks are siped wherein the siping density decreases from the tread center to the tread shoulders.

Abstract: A tire tread for a pneumatic tire has a center rib and a series of steeply slanted grooves in each side region of the tread, the circumferentially adjacent grooves form blocks extending through the tread side regions. The center rib has a serrated configuration along each lateral side and a supporting chamfer extending from each serration point. Adjacent to each rib chamfer is a chamfer extending from the axially innermost point of the rib at the junction of two adjacent steeply slanted grooves. The rib is provided with high density siping. The tread blocks are siped wherein the siping density decreases from the tread center to the tread shoulders.

Abstract: There is provided a pneumatic tire, particularly a high-performance tire capable of effectively enhancing a drainage property without sacrificing the other tire properties, wherein a pseudo-land portion (11) promoting a smooth inflow of water flowing in circumferential grooves (3), (4) into slant grooves (7a), (7b) is formed in the circumferential groove (3), (4).

Abstract: In a pneumatic tire comprising a tread portion divided into a central region and both side regions, at least one rib-shaped main land part is formed in the central region and a plurality of main slant grooves are arranged so as to extend obliquely from the central region toward each tread end of the tread portion with respect to the equatorial plane to form first slant land parts among these main slant grooves, in which the first slant land part has a plane form of approximately a triangle, and a first auxiliary land part is arranged between the rib-shaped main land part and the main slant groove.

Abstract: A tire for vehicle wheels includes a tread band having a tread pattern defined between two shoulder ends of the tire. The tread pattern includes two lateral rows of grooves and at least one third row of grooves arranged between the lateral rows. All of the grooves are separate from one another so as to produce a pattern with no intercommunicating paths between the grooves. End portions of the grooves of the at least one third row extend outside a footprint of the tire. A dimension of each of the grooves of the at least one third row relative to a length of the tire footprint causes water drainage from underneath the tire footprint. A tire including the ability for acoustically signalling low air pressure, a method for checking tire air pressure using an acoustic signal, and an acoustic signalling device for vehicle wheels are also disclosed.

Abstract: A tyre for vehicles includes a carcass structure, a belt structure, and a tread. The tread includes a row of central blocks and a row of intermediate blocks arranged on each side of an equatorial plane of the tyre between a central longitudinal groove formed astride the equatorial plane and a pair of longitudinal lateral grooves. The blocks of the central rows are separated from the blocks of the intermediate rows by circumferential sipes and are circumferentially staggered by a first predetermined quantity relative to the blocks of the intermediate rows. Also, the blocks of the central rows arranged on a first side of the equatorial plane of the tyre are circumferentially staggered by a second predetermined quantity relative to the blocks of the central rows on a second side of the equatorial plane of the tyre.

Abstract: A tire has a tread on the outer circumferential surface. The tread has circumferential and lateral grooves defining tread blocks. In at least one tread block, one of the circumferentially extending sides of the block has a multi-planar chamfer.

Abstract: A pneumatic tire having a directional tread pattern of a designated rotating direction comprises at least one circumferential main groove at a central region of a tread portion, a circumferential sub-groove at each of side regions of the tread portion, a plurality of slant grooves extending in the shape of an unfolded fan and opening at the end of the tread portion, and blocks defined by these grooves, in which a central block located nearest to an equatorial plane of the tire has such a headland part that a corner part facing to the sub-groove at a leading end side in the rotation of the tire taperingly projects into a joint part between the sub-groove and the slant groove, and the headland part has a surface form that a height from a groove bottom of the joint part and a length in the circumferential direction gradually decrease toward the end of the tread portion.

Abstract: A pneumatic tire for motor vehicles has a running surface profile designed in the direction of rotation, with two shoulder regions (S1, S2) each being a constituent of a row of shoulder blocks, and with a middle region (C) separated from them by circumferential grooves (2) running in the circumferential direction; this middle region encompasses the width of the circumferential grooves (2) and covers a minimum width of 60% of the width of the running surface (B), is free from circumferential grooves running in the circumferential direction and is equipped with a number of V-shaped running rills (1), which open into the circumferential grooves (2) and whose V-peaks rest at least essentially on the equator line (M—M).

Abstract: A tread (1) for steer axle tires for a heavy vehicle, the tire having a preferred direction of travel, the tread comprising grooves (2) of generally circumferential orientation defining at least three ribs (30, 31, 32, 33, 34), two of the ribs forming the edges (30, 34) of the tread, some of the intermediate ribs (31, 32, 33) being provided with a plurality of incisions (41, 42, 43), of general transverse orientation and substantially parallel to each other, the incisions having an average inclination other than zero relative to the direction perpendicular to the running surface of a new tread, this tread being characterised in that, when viewed in a section plane perpendicular to the axis of rotation of the tyre, the incisions in the intermediate ribs form, on and in the vicinity of the running surface when new of the tread, an angle close to or equal to 0° with a line perpendicular to said surface at the point of intersection, whereas the angle of each of these incisions increases in the depth of the tr

Abstract: In a motor vehicle tire (1) for driving conditions as they occur during the winter months, parallel incisions are provided with staggers that are placed such that a smaller distance between adjacent incisions arises in the central region of the pad than in the marginal region of the pad.

Abstract: A very high performance tire (1, 101) for vehicles comprises a tread (14) provided with a plurality of transversal grooves (15) circumferentially distributed along the tread (14) in groups alternately extending from opposite shoulder zones (F, G) of the tread (14). The transversal grooves (15) define in an equatorial zone (E) of the tread (14) a substantially isotropic matrix of substantially continuous portions (18) of the tread (14) terminating at an equatorial portion (17) of a same transversal groove (15) of the axially opposite group of grooves.

Abstract: A pneumatic tire is disclosed in which ABS braking performance on a wet road after being worn is improved. This pneumatic tire includes: a tread pattern whose rotational direction is specified; and a block plotted on a tread by main grooves extending in a tire circumferential direction and lateral grooves extending in a tire width direction, the block having a pair of opposing corners with acute angles and including at least one sipe therein.

Abstract: A pneumatic tire comprising a tread portion provided with oblique grooves to define narrow and circumferentially long blocks therebetween, the oblique grooves inclined at angles &thgr; of not more than 60 degrees with respect to the circumferential direction of the tire, each of the long and narrow blocks provided with at least tow sipes each extending across the block from one of the adjacent oblique grooves to the other, while inclining reversely to the oblique grooves, to subdivide the block into at least three block pieces.

Abstract: A tire tread having grooves of transverse general orientation defining a plurality of blocks arranged so as to form a tread pattern having a preferred direction of travel, the blocks having a contact face, two lateral faces, a leading face forming an angle a greater than 90° with the contact face and a trailing face. For at least one tread pattern block, the trailing face of the block is formed of an upper part extending from the running face of the block which is extended towards the inside of the tread by a lower part. Furthermore, the upper part of the trailing face is undercut and forms an angle &bgr; of less than 90° with the contact face, whereas the lower part, which is inclined so as to form an angle &dgr; greater than 90° with the contact face, is provided with at least one recess which extends into the interior of the block.

Abstract: A tire tread comprises an intermediate portion disposed between two shoulder portions. The tire tread has an expanded void area with a width and length of 1.2 to 5 times the average width of a non-circumferential groove in the tread. In the illustrated embodiment, the expanded void area is in the intermediate portion of the tread and the void area is divided into two branches which are separated by an island of tread rubber. The illustrated island has a length and a variable width, and has rounded leading and trailing ends. The island is also disposed at an angle with respect to the centerline (CL) of the tread. In the illustrated embodiment, the tread has a circumferential aquachannel, and the islands and the aquachannel are in close proximity to one another.

Abstract: In a pneumatic tire of the present invention, a pair of circumferential main grooves with a tire equatorial plane interposed therebetween, and another pair of circumferential main grooves at a tire axial direction outer side and inner side of the former pair of circumferential main grooves, are provided in a central area of a tread. A groove width center line of the circumferential main grooves at the tire axial direction outermost side and innermost side is disposed at a position 30% to 40% of a ground contact half width distanced from the tire equatorial plane. Further, outboard side slanted longitudinal main grooves, and slanted lateral main grooves having ends which open into at least one of the circumferential main grooves and other ends which open into contact ground end in the vehicle width direction, are disposed on the tread.

Abstract: A pneumatic tire according to the present invention includes a tread surface having a tire rotation direction designated in one direction. The tread surface has a straight main groove extending in a circumferential direction of the tire in the center, and lateral grooves obliquely extending in a width direction of the tire on both sides thereof, defining blocks thereon. On both sides of the straight main groove, left and right slant main grooves are arranged to cross three or more lateral grooves. Both ends of-the slant main grooves are positioned within the blocks, and the groove width thereof is gradually enlarged from both end portions toward the center portion of the slant main groove. The inclination angle of the slant main grooves relative to the tire circumferential direction is set in a range of 10 to 45°, and the maximum groove width thereof is set to 80 to 110% of the groove width of the straight main groove.

Abstract: A pneumatic radial tire having excellent steering stability, resistance to hydroplaning and noise reduction comprises a carcass, a belt and a tread portion provided with a plurality of tread grooves and having an aspect ratio of not more than 50%, in which a ratio of ground contacting width of tire tread to rim width under measuring conditions defined in ETRTO is less than 0.85 and a negative ratio is not more than 25%.

Abstract: An off-road tire has sidewall tread element extensions with steps that provide gripping action and support around the sidewall, and enable the tire to climb the sides of rocks and ruts. The steps are located at different distances from the tire rotational axis and from the tire tread centerline.

Abstract: When a single performance or a plurality of antinomical performances are to be achieved, the best mode of a tire is designed under a given constraint condition. Each of blocks included in two pitch groups designated in a pitch array is modeled (100), an objective function representing a tire performance evaluation physical amount, a constraint condition for restricting a tire shape, and a design variable which is an angle of a wall surface determining each of block shapes are determined (102). Next, the design variable is varied continuously by &Dgr;ri to determine a modified model (104 to 108). A value of the objective function of the modified model and a value of the constraint condition are calculated, and a sensitivity of the objective function and a sensitivity of the constraint condition are determined (110, 112).

Abstract: A tire having a ground contacting tread, the tread having a directional tread pattern comprising at least two substantially circumferentially extending grooves disposed one each side of the tread circumferential centerline and a plurality of circumferentially spaced apart and substantially axially extending shoulder grooves extending axially outwardly from each circumferential groove to the tread edge to define a row of tread blocks in each axially outer tread shoulder part, the axially extending grooves having two opposing inclined sidewalls which provide ramp support to the adjacent tread block edge, characterized in that each of the axially extending shoulder grooves has a groove depth which reduces from the axially inward part to towards the axially outer part, and each groove comprises two groove main portions connected end to end, each groove main portion having a varying asymmetric cross-section along its length, each groove main portion having a first groove sidewall having a constant first angle of i

Abstract: A pneumatic tire that is designed primarily for use on paved surfaces, but may have application off-road, has extended chamfers aligned in a portion of the tire. In the illustrated embodiment, the chamfers are on leading and trailing portions of the lugs, are aligned axially in the tread, and together with acutely angled grooves in the tread, create an open, teeth like appearance in the tread.

Abstract: A studless tire which is provided in the tread portion with one or more circumferential portions provided with V-shaped sipes, the total width of the one or more circumferential portions is in a range of from 10 to 25% of the tread width, each V-shaped sipe is composed of two parts extending from its vertex located in a central region of the circumferential portion, and the V-shaped sipes in each circumferential portion are oriented towards the same direction and arranged at intervals in the tire circumferential direction.

Abstract: A pneumatic tire comprises a tread portion provided with a wide groove having a bottom width of not less than 20 mm. The wide groove is provided on the groove bottom with at least one longitudinal rib extending in the longitudinal direction of the wide groove, and lateral ribs extending from the longitudinal rib towards a tread face through the groove bottom and a groove wall of the wide groove, whereby occurrence of bareness of tread rubber in the groove bottom can be prevented.

Abstract: A pneumatic tire has a circumferentially continuously extending wide groove having a width of from 35 to 45 mm disposed in a tread center. A part on each side of the wide groove, which is defined as extending at least 10 mm axially outwards from the groove edge, forms a substantially continuous rib part. A part between the rib part and a tread edge has circumferentially discontinuous grooves so that: an axially inner part has a land ratio La of not less than 90%; a middle part has a land ratio of Lb in a range of from 80 to 90%; and an axially outer part has a land ratio Lc in a range of from 85 to 95%, wherein the axially inner part, middle part and axially outer part are three equiwidth parts between the wide groove and the tread edge.

Abstract: A radial ply pneumatic tire 10 for trucks or trailers has a tread 12 with at least three circumferential grooves 20,22 extending circumferentially to divide the tread 12 into at least four parts and lateral grooves 30,31,32,33,34 extending across the at least four parts of the tread to form at least four rows 1,2,3,4 and 5 of circumferentially separated blocks 40. The circumferential grooves 20,22 have average groove widths of W1 for a depth between the radially outer surface of the adjacent blocks and a groove depth that is less than 60% of the non-skid depth D, the circumferential grooves having a second average groove width W2 at the groove depth less than 60% of the non-skid depth D, the second average groove width W2 being less than 50% of W1. The lateral grooves 30,34 in each shoulder row 15 have a first average groove width W3 and a groove depth that is less than 60% of the non-skid depth D.

Abstract: The tread surface of a tire for use on an aircraft landing gear includes a plurality of cavities that are formed within the bearing surface. The cavities have a front surface extending from the bearing surface to the bottom of the cavity, the front surface being preferably substantially normal to the tread surface at that location, i.e., radially with respect to the tire, and substantially normal also to the circumference of the tire. The cavities include a second surface that slopes from the bearing surface toward the front surface at the bottom of the cavity. A tire, utilizing such a tread pattern, when positioned such that relative wind is directed toward the front surfaces of the cavities when the tire is at its bottommost position of revolution, experiences self-rotation, achieving a velocity and direction of rotation substantially commensurate with the velocity of the relative wind.

Abstract: A pneumatic tire for motor vehicles has a running surface profile designed in the direction of rotation, with two shoulder regions (S1, S2) each being a constituent of a row of shoulder blocks, and with a middle region (C) separated from them by circumferential grooves (2) running in the circumferential direction; this middle region encompasses the width of the circumferential grooves (2) and covers a minimum width of 60% of the width of the running surface (B), is free from circumferential grooves running in the circumferential direction and is equipped with a number of V-shaped running rills (1), which open into the circumferential grooves (2) and whose V-peaks rest at least essentially on the equator line (M-M).

Abstract: A pneumatic tire having improved wet traction has two annular aquachannels. The tire has a wide, substantially square footprint, a distinctive tread pattern, and a new tread compound, and exhibits good QGL wet traction in addition to excellent hydroplaning properties. The tire also has good handling and wear properties.

Abstract: A tread 2 for a pneumatic tire 1 has a central portion defining two circumferentially extending center ribs 22, 23 having an axial width RW, and RN2 ranging from 5% to 25% of the tread width TW. The centermost circumferentially extending groove 8 has on both sides a tapered groove wall edges which form with a plane parallel to the equational plane acute angles &agr;1 and &agr;2 ranging between 1 and 10°. The tread height near both edges of the centermost groove extend radially above the average tread height a maximum extra tread height of between 0.3 mm and 1.7 mm. The extra tread height diminishes progressively from the groove edges P0 P1 toward the respective shoulder 3,4 a distance not exceeding 10% of the treadwidth.

Abstract: A tire (1) having low rolling resistance, in particular for driving wheels of heavy vehicles, comprises a tread (14) provided with a plurality of transversal grooves (20) pitchwise spaced from one another and extending in a direction substantially perpendicular to the rolling direction of the tire (D). The grooves (20) have a reduced depth and are provided with respective slits (24), extending from a bottom portion (21) thereof; as such, they contribute to impart to the tire (1) both the desired low rolling resistance and an adequate traction characteristics during straightaway running.

Abstract: A passenger tire having a tread, a casing with two sidewalls, one or more radial plies extending from and wrapped about two annular beads and a belt reinforcement structure located radially between the tread and the piles. The tread has a central rib with a first contour-defining curve extending outwards from the mid centerline of the tire towards the sidewalls and a pair of side ribs each having a second contour-defining curve disposed between the central rib and the sidewalls. The first and second contour-defining curves each have first and second radii disposed such that the meeting point of first and second adjacent contour-defining curves cannot contain a single line that is mutually tangential to the first and second adjacent contour-defining curves.

Abstract: This invention relates to off-road tires, more specifically, a preferred embodiment of this invention relates to a pneumatic all-terrain vehicle tire having puncture prevention pads 72.

Abstract: A farm tractor has a vehicle having a pair of pneumatic agricultural tires 20 having an asymmetric directional tread 32 with lugs 50A,50B,50C arranged in a chevron type pattern 70,72. The chevron pattern 70,72 is asymmetric having the apex or point 74 lying entirely on one-half 32A or 32B of the tread 32 thus creating soil discharge channels 89,82 that are greater on one tread half 32A or 32B relative to the other tread half 32A or 32B. This tread pattern permits the employment of lugs 50A, 50B of substantially equal lug length ll insuring more uniform wear characteristics.

Abstract: A vehicle tire comprising a tread in which tread grooves (2, 4, 5, 6) are molded, wherein tread grooves (2) are provided for the improvement of the leading away of water and are curved in such a way that during the rolling of the tire, they always open at least substantially perpendicularly into the front boundary line (1) of the tire contact patch.

Abstract: The present invention relates to an improvement to block-type tread patterns for pneumatic tires (110,210). To balance heel-toe wear, the heels (126,226) of one or more of the blocks are provided with one or more notches (130,230). The application of an appropriate number, shape, and size of notches provides the blocks with a variable net to gross where the void space decreases from the heel to the toe. With increased void space, the wear rate of the heel is increased to balance the wear rate at the toe.

Abstract: A pneumatic tire for passenger car has a direction tread pattern defined by a plurality of circumferential grooves and a plurality of directional slant grooves arranged at given intervals in the circumferential direction, wherein a circumferential center rib is formed in the central zone of the tread by a pair of circumferential center grooves, and a pair of circumferential middle ribs are formed by the pair of circumferential center grooves and a pair of circumferential side grooves, and a pair of circumferential side ribs are formed by the pair of circumferential side grooves and a pair of tread ends, and the directional slant grooves are directional slant center grooves formed in the circumferential middle rib and directional slant side grooves formed in the pair of circumferential side ribs, provided that each of the directional slant center grooves is opened to either of the circumferential center groove and the circumferential side groove and terminated in the circumferential middle rib and each of the

Abstract: A pneumatic tire is provided in which hydroplaning performance, transverse slipping performance on snow, straight forward traveling stability, and the like are maintained by a pair of circumferential grooves. A large number of second blocks and center blocks are formed, by a large number of transverse grooves, in a center tread region positioned between the pair of circumferential grooves. A reinforcing portion is provided at the center block. This reinforcing portion faces, in a circumferential direction, the second block with a narrow transverse groove therebetween. Another reinforcing portion is provided at an end portion of the second block. This reinforcing portion faces, in the circumferential direction, the center block with a narrow transverse groove therebetween. Each block is reinforced by the reinforcing portion provided integrally therewith. When a block receives load in a direction of deformation, the block abuts and is supported by the reinforcing portion of a block adjacent thereto.

Abstract: A vehicle tire has an unidirectional tread pattern, and the tread portion is provided with two circumferential grooves to divide the tread portion into two outer parts and a central part there between, the central part being substantially continuous in the tire circumferential direction and formed symmetrically about the tire equator. The outer parts are provided with mirror-image patterns, each formed by circumferentially repeating pattern units having an average circumferential length, and the mirror-image patterns are circumferentially shifted from each other by a distance S of from 0.15 to 0.25 times the above-mentioned average circumferential length.

Abstract: A pneumatic tire including a tread portion provided with two circumferential grooves to divide the tread portion into a pair of shoulder parts and a central part therebetween, each of the circumferential grooves has such a relatively wide width that the maximum axial width (GWmax) thereof in the foot print is not less than 35 mm, and in a meridian section of the tire, the axially inner sidewall each circumferential groove is substantially straight and inclined axially inwards, and the axially outer sidewall of the circumferential groove comprises a convex part extending axially outwardly to a merge point at which the convex part merges into a ground contacting top surface of one of the should parts.

Abstract: A tire comprises a tread portion in which a mold parting line by a single-split mold runs on or near the tire equator. In a central part of the tread portion in which tread grooves are provided, the groove edges which are stroked by tire mold's protrusions for making the tread grooves when the mold is opened are provided with a chamfer backed by a recess and/or the groove walls extending from such groove edges are provided with a variable inclination, whereby demolding defects can be reduced.

Abstract: A pneumatic tire is provided in the tread center region with a wide main groove extending continuously in the tire circumferential direction, the main groove divides the tread into two lateral parts, each of the lateral parts is provided with no groove extending continuously in the tire circumferential direction, the main groove has a groove width of not less than 35 mm, the main groove has zigzag edges each having a zigzag amplitude of not more than 0.4 times the groove width, and parts of the zigzag edges which are defined as protruding towards the center line of the main groove are rounded by an arc, and the radius of curvature of the arc is in the range of from 2 to 15 mm when measured in the tire meridian section at the peak of the protruding part.