Abstract: A pneumatic tire of the present invention, which has a bead core buried in a bead portion, in which a ratio dw/D of an inner diameter dw of the bead core to a heel diameter D of a rim, which is specified in a public standard, and a ratio dt/D of a heel diameter dt of the bead portion to the heel diameter D of the rim satisfy the following inequalities: 1.009<dw/D<1.022 0.980<dt/D<0.

Abstract: Disclosed is a pneumatic tire adopting a bias ply structure in which plural carcass layers are disposed so that cords cross each other between the layers, and having an aspect ratio of 55% or less and an outer diameter of 300 mm or less, wherein a cord angle to a tire circumferential direction of said carcass layer is set to a range from 27 to 37° in the center line position, and a surface shape of a tread portion is formed to be straight to a tire width direction in the region of 60 to 75% of a tread width.

Abstract: A pneumatic radial ply tire with an aspect ratio of less than 50 has a ground contacting tread radially outward of a circumferential belt structure which in turn is radially ourtward of a carcass structure. The carcass structure has a pair of bead areas that include a bead foot compatible with a conventionally-shaped wheel rim having flanges with laterally extending portions. The carcass structure has a cord-reinforced elastomeric ply layer extend laterally between the two bead areas and radially inward of the belt structure. The tread area is directly connected to the bead areas without a sidewall. Rim flange protectors comprising a continuous circumferential elastomeric projection extend laterally outward from each bead/tread area and thereby radially outward of the rim flanges.

Abstract: The tire of the invention has an optimized path of the outermost carcass designed to maximize the extent of tensile stress in the sidewall and bead portions of the tire. The invention further provides separate reinforcement structures in the bead portion for anchoring the carcass or carcasses in the bead and for retaining the bead on the mounting rim during deflated operation, and said anchoring reinforcement also facilitates the maintenance of the desirable carcass profile.

Abstract: A pneumatic tire with an increased load carrying capacity (extended load index) but compatible with conventional, commercially available wheel rims, has a modified carcass ply line. The pneumatic tire (746) has a tread area (712) and a carcass structure (728) including two bead areas (750a,750b), at least one cord-reinforced elastomeric ply (730) extending through sidewalls (726a,726) between the bead areas (750a,750b) and the tread area (712), and a belt structure (718) between the tread area (712) and the carcass structure (728). The tire (746) has bead areas (750a,750b) containing a triangular shaped beads so that the ply line (PL′″) that causes the bead areas to better secure the tire to the rim during high stress conditions.

Abstract: A tire with a form ratio H/S between 0.3 and 0.8 has a carcass reinforcement (1) which is covered radially by a quasi-cylindrical crown reinforcement (3) and which is tangential at T to a holding circle C. The common tangent at T to the circle C and to the meridian profile of the carcass (1) makes an angle &agr; of between +20° and −80° with respect to a line parallel to the rotation axis and passing through the tangency point T. In its portion located between the tangency point T and the point E of greatest axial width, the carcass reinforcement (1) is provided with a reinforcement armature (6) of circumferentially non-extensible elements. Viewed in meridian cross-section and when the tire is fitted and inflated to the recommended pressure, the carcass (1) has a meridian profile consisting of four circular arcs configured to improve the endurance of the tire while improving its rolling resistance.

Abstract: A tire comprising at least one reinforcement structure of the carcass type anchored on either side of the tire in a bead, the base of which bead is intended to be mounted on a rim seat, the reinforcement structure extending circumferentially from the bead towards the sidewall, at least one arrangement of main cords along a substantially circumferential path being arranged substantially adjacent to the structure, the arrangement of the cords of the at least one arrangement being such that the number of main cords arranged on the axially inner side relative to the structure is greater than the number of main cords arranged on the axially outer side relative to the structure.

Abstract: As agricultural tire 20 for the driveaxle of a vehicle has an aspect ratio of greater than 95%. The tire 20 has a nominal rim diameter of 20 inches or greater.

Abstract: An apparatus and method that determines a maximum road friction coefficient for each wheel regardless of whether the tire is in a predetermined drive slip state, and whether the wheel is a driving wheel. The braking force of each wheel is calculated, and the longitudinal force of the tire of each wheel is calculated. Then, the driving force of the vehicle is calculated, and the lateral force of the tire of each wheel is calculated. Next, the reaction force of the road to each wheel is calculated, and the vertical load of each wheel is calculated. Finally, the ratio of variation in reaction force of the road to variation in composite slip ratio is calculated for each wheel. The sum of the ratio of the reaction force of the road to the vertical load, and the product of a predetermined coefficient and the ratio of variation in reaction force of the road to variation in composite slip ratios is calculated for each wheel as the maximum road friction coefficient.

Abstract: A tire, at least one radial carcass reinforcement of which is anchored within each bead B to two bead wires and to form an upturn, characterized in that, viewed in meridian section, an additional reinforcement armature, formed of at least one ply of circumferential reinforcement elements, is placed, at least axially to the inside, along the carcass reinforcement in the region of the bead B.

Abstract: A pneumatic tire having a toroidal carcass satisfies the following expressions: Ra/D≦0.08; Rb/D≦0.08; 0<&phgr;a≦50°; and 0<&phgr;b≦50°. Alternatively, the pneumatic tire has a tire section constant J per a unit circumferential length of 0.8 or smaller.

Abstract: A pneumatic tire with an increased load carrying capacity (extended load index) but compatible with conventional, commercially available wheel rims, has a modified carcass plyline. The tire has a tread area, a carcass structure including two bead areas each comprising a bead, at least one cord-reinforced elastomeric ply extending between the two bead areas, and two sidewalls, one sidewall extending between the tread area and each bead area.

Abstract: A tire (1), a mounting rim (2) therefor and a circumferentially unstretchable ring (3) for supporting the tread (10) of the tire when running at low or zero pressure. The tire (1) has a radial ply casing (13) on which the points that are furthest apart axially are radially apart close to seats (12B) of outwardly sloping beads (12). The seats (12B) engage sloping seats (23′, 23″) on the rim (2), which may have at least one mounting well (22), at least one cylindrical portion (21) for receiving the supporting ring (3) and rim flange (24).

Abstract: A pneumatic radial tire combination for four-wheeled automobile or light truck vehicles. The tire combination has a pair of front steer position tires and a pair of rear position tires. The front steer position tire 10 has a first tread arc 46 when the tire is normally inflated for normal load but unloaded, of decreasing radii extending toward the lateral edges 42, 44 and a straight line 50 drawn between the intersection of the tread arc curvature and the centerplane is inclined at an angle &thgr;F of greater than 5° relative to a tangent line L, L being tangent to the tread arc at the centerplane and parallel to the axis of rotation R. The rear tire 20 when similarly measured has a tread arc having an angle &thgr;R of less than 5°.

Abstract: A pneumatic radial tire having in axial cross-section a highly curved tread reinforced by a breaker assembly with improved resistance to breaker edge looseness. The breaker assembly includes one breaker ply which extends between two bead regions and has its edges disposed between a carcass main portion and a carcass turn-up portion.

Abstract: A tire with radial carcass reinforcement, having a crown reinforcement embodying at least two working crown plies formed of inextensible cables, crossed from one ply to the next, forming angles of between 10° and 45° with the circumferential direction, characterized in that, in the absence of any ply formed of inextensible cables forming an angle greater than 45° with the circumferential direction, an additional, axially continuous, ply formed of undulating metallic elements oriented substantially parallel to the circumferential direction is placed radially between the working plies.

Abstract: A pneumatic tire having at least two or more pieces of carcasses, wherein a high hardness rubber component sheet, which has tensile stress of 2.0 MPa or more when extended by 20% to a tire circumferential direction and JIS-A hardness of 65 or more, is arranged at least between carcass plies at a tread portion.

Abstract: A wheel-mounted floating vehicle with superlow pressure tires which creates average ground pressure 0.008-0.009 MPa and does not destroy vegetal soil layer. The ratio of the total mass of the vehicle to the product of the overall diameter (D) of the tire, the section width (B) and the number of wheels fitted with tires ranges between 0.001-0.006 MPa, and the ratio of the mass of each tire to interior volume thereof lies within the limits of 35-80 kg/M3. The radial deflection of the tire with atmospheric interior pressure under the influence of the own mass of the wheel fitted with the tire ranges between 15-45 % of section height (H) of the tire. The interior pressure in the tire varies from 0,005 MPa up to 0,05 MPa. The invention is particularly intended for use in permafrost regions, in the tundra, in swamped areas, in sand deserts as well as in other remote regions.

Abstract: A tire, the H/S form ratio of which is at most 0.6, formed radially from the inside to the outside by a triangulation ply of metal cables oriented at least 60°, two working crown plies formed of inextensible metal cables oriented at angles of between 10° and 45°, between which there is inserted a first additional ply of metallic elements which are oriented substantially parallel to the circumferential direction of the tire, a second additional ply being arranged, on either side of the tire, radially above the outermost working ply and substantially centered on the end of the first additional ply.

Abstract: A radial ply pneumatic tire 30 has a unique cross sectional profile. The tires rum flange width W is greater than the tread width TW and the maximum section width SW is located radially less than 50% of the section height SH as measured from the nominal rim diameter ND.

Abstract: A tire wheel for vehicles comprises a mounting rim which can be associated with a hub of a vehicle and is provided with two bead seats forming a cone, for engagement with corresponding beads of a tire, with its apex on said axis of rotation in a position axially outside said rim, a tire comprising a toroidal carcass provided with a crown portion connected to a pair of axially facing sidewalls terminating in beads for engagement with the corresponding bead seats formed on the rim, said tire having its maximum width in the region of said beads, and an inner tube inserted into the toroidal cavity defined between tire and rim, elastically expandable by means of the introduction of fluid under pressure into its internal volume, and provided with an inflating and deflating device inserted in the wall of said inner tube, without any element for connection to the environment outside the wheel, in particular passing through the wall of the rim.

Abstract: This invention provides a product shape designing process for designing an optimal product shape, particularly a pneumatic tire contor in a cross section, comprising the following steps. A shape generation step of setting plural basal shapes and linearly combining the basal shapes to generate plural sample product shapes, a performance evaluation step of obtaining evaluation values on a product performance of the sample product shapes generated in the shape generation step, and a product shape extraction step of extracting an optimal product shape whose evaluation value on the product performance is an optimal value based on the evaluation values on the product performance obtained in the performance evaluation step. This process realizes a smooth optimal tire contor that reduces rolling resistance coefficient while increasing lateral spring constant of the tire for good drivability.

Abstract: A mold for tire vulcanization that includes axially opposite sidewalls and a tread band molded with a raised pattern formed with at least one circumferential groove. The mold has a pair of axially opposite cheeks corresponding to the sidewalls of the tire and a matrix interposed between the cheeks, which corresponds to the tread band. The matrix has a plurality of ribs projecting in a raised configuration from a bottom surface. The sectional profile of the bottom surface comprises two distinct concave side portions and the sectional profile of the surface tangent to the ridge of the ribs in the area included between the side portions has a convexity directed radially inwardly.

Abstract: A radial tire when mounted on a rim and filled to normal inner pressure has a ratio of the upper cross-sectional height USH to the cross-sectional height SH between 0.50 and 0.59, a ratio of the lower cross-sectional height LSH to SH between 0.40 and 0.50, a rim width of more than 1.40 times the measuring rim width MRW but less than 1.45 MRW, an aspect ratio of less than 0.65, a beadfiller height of greater than 0.224 SH, and an angle between the tangent to the carcass line at a bead upper point B and a line extending in parallel with the rotation axis of the tire is less than 45°.

Abstract: A pneumatic tire, which is adapted for a standard wheel rim, comprises a tread portion, a pair of sidewall portions, a pair of bead portions, a carcass extending between the bead portions, and a rim flange holder disposed on each side of the tire and protruding axially outwardly so as to overhang a flange of the standard wheel rim. The rim flange holder has a hooking part extending radially inwardly on the axially outside of the flange so as to hook the flange. The radial measurement between the radially outermost point of the flange and the radially innermost point of the hooking part is at least 2 mm, and the rim flange holder is provided with a slit extending axially inwardly from the axial outer surface of the rim flange holder.

Abstract: A pneumatic radial tire having in axial cross-section a highly curved tread is reinforced by a breaker assembly with improved resistance to breaker edge looseness. The breaker assembly includes one breaker ply which extends between two bead regions and has its edges disposed between a carcass main portion and a carcass turn-up portion. An improved single-stage method may be employed for building the tire.

Abstract: A high-transverse-curvature tire (1), in particular for mounting onto the rear wheel of motor-vehicles, comprises a tread band (8), coaxially extended around a belt structure (6), wherein a plurality of rubber blocks (10), defined between a plurality of grooves (1 1) extending along a direction substantially transverse to the tire running direction (D), are formed which grooves comprise a bottom (12) connected to opposite inlet (13) and outlet (14) sidewalls. In an equatorial zone (E) of the tread band (8), the inlet wall (13) of the grooves (11) is inclined with respect to the bottom (12) of the same towards the tire rolling direction, and forms an angle (&agr;) of from 50° to 80° with respect to a plane (&pgr;) tangent to the bottom (12).

Abstract: A tire (1) for motor-vehicle wheels comprises a tread band (10) and a belt structure (6), the tread band being molded with a raised pattern having a circumferential groove (11). In the absence of load and inflating pressure, the tire is characterized in that the belt structure in a cross-section of the tire has an axial profile comprising three distinct portions, first (14) and second (15) side portions and one central portion (16) interposed between the side portions. The side portions are concave at a radially internal position, in which the concavity is defined for each portion by a respective center and a respective radius of curvature. The central portion is concave at a radially external position where the concavity center of the central portion lies in the center line plane of the circumferential groove, in which the depth of the radially external concavity is canceled under the effect of the normal inflating pressure of the tire.

Abstract: A tire (10) having a contoured precured bead filler or apex (40) with a contoured surface for directing the ply path (24A) of the cord reinforced carcass plies (24) is taught. The contour of the precured bead filler or apex (40) has a convex surface (42A) and concave surface (42B) that transition at an inflection location (T) at or below the rim flange (52) to which the tire (10) is to be mounted.

Abstract: A tire and wheel assembly for a forklift type vehicle includes a rim having an annular well to enable fitting of tubeless tires and a tire having an aspect ration of 58% or less. The tire is inflated to a pressure of at least 125 pounds per square inch (psi) and has fabric cross plies extending a distance of at least 30% up the inner face of the side walls of the tire.

Abstract: A low pressure tire including a torus of flexible, substantially inelastic material. The material will not deform at a temperature of about 225° F. The torus includes an inner diameter surface for engaging a tire supporting rim and an outer diameter surface for contacting a support surface. The torus can flatten under a load to facilitate movement of the tire over soft or irregular support surfaces. A sealable opening permits the inflation and deflation of the torus.

Abstract: A pneumatic radial tire for motorcycle comprises a belt containing cords extended substantially in a circumferential direction of a tread and has a directional tread pattern defined by plural main slant grooves having a given inclination angle with respect to the circumferential direction and extending from a tread center up to a tread shoulder region and a slant sub-groove arranged between the slant main grooves and having an inclination angle smaller than that of the slant main groove, in which the slant main groove has a given width in connection with a periphery length between both ends of the tread at a particular posture under a given air pressure; a main portion of the slant sub-groove is terminated so as not to open into the slant main groove and has given groove width, length in the circumferential direction of the tread, and depth.

Abstract: A pneumatic tire has an outer surface provided with a mid-lower sidewall contour S1 and a lower sidewall contour S2, the contour S1 extends radially inwardly from the maximum cross sectional width point P1 of the tire to a point P12 along a circular arc line E1 having a single radius R1 and the center on an axial line passing the maximum cross sectional width point P1, the contour S2 extends on the axially inside of the circular arc line E1 from the point P2 to a radially inner point P3, the rubber thickness T measured from the tire outer surface to the main portion of a carcass is gradually increased from the point P1 to the point P2.

Abstract: The belts of the reinforcing structure of a pneumatic tire are reinforced with high strength, light weight aramid cords having a linear density of 420 to 1100 dTex, the cords having a twist of 315 to 551 TPM (8 to 14 TPI). In alternative embodiments, overlay material may be incorporated into the belt reinforcing structure. An illustrated embodiment of the tire has a belt reinforcing structure comprising a folded belt folded around a cut belt.

Abstract: A motorcycle tire comprises a tread portion curved convexly such that the maximum cross section width TW of the tire lies between the tread edges, a carcass ply of cords arranged radially at an angle of 70 to 90 degrees to the tire equator, and a belt ply of at least one cord laid at an angle of 0 to 35 degrees disposed radially outside the carcass ply in the tread portion. When the tire is mounted on a standard rim and inflated from 10% of a standard inner pressure to 100% thereof, the tread portion swells such that the amount of swelling is larger in a shoulder region than a crown region of the tread portion. The carcass cord tension Tcs in the shoulder region is 2.0 to 3.8 times the carcass cord tension Tcc in the crown region, and the belt cord tension Tbs in the shoulder region is 1.2 to 2.0 times the belt cord tension Tbc in the crown region.

Abstract: A tire for two-wheeled vehicles is described, said tire having a transverse curvature coefficient with a value of not less than 0.15, comprising a torus-shaped carcass having structural means which allow improvements in the handling of the vehicle, while leaving unchanged the other performance characteristics, in particular the comfort. These structural means consist in at least one ply of a rubberized fabric provided with textile cords having a count of between 420/2 and 840/2 dtex and a modulus of elasticity of between 100,000 MPa/cm and 200,000 MPa/cm. Preferably the carcass comprises a pair of these rubberized fabric plies reinforced with PEN cords.

Abstract: A run-flat tire comprises a carcass ply extending between the bead portions, and a sidewall reinforcing layer disposed axially inside said carcass ply in each sidewall portion, wherein in a normally inflated unloaded state, a profile line from a tire equator point (P) to a maximum tire section width point (D) is curved substantially along an involute curve so as to have a radius of curvature decreasing continuously from the tire equator point towards the sidewall portion, the basic circle of the involute curve is an ellipse whose major axis extends in the tire radial direction, the radial distance (h) between the tire equator point (P) and the maximum tire section width point (D) is more than 34% but less than 50% of the tire section height (H).

Abstract: When a single performance or a plurality of antinomical performances are to be obtained, the best mode of a tire is designed under a given condition. A basic shape model using one block as a reference shape is obtained (100). An object function representing a tire performance evaluation physical amount, a constraint condition for restricting the tire shape, and a design variable which is an angle of a wall surface which determines the block shape are determined (102). Next, the design variable is varied continuously by &Dgr;ri to determine a modified shape model (104 to 108). A value of the object function of the modified shape model and a value of the constraint condition are calculated, and a sensitivity of the object function and a sensitivity of the constraint condition are determined (110, 112).

Abstract: A pneumatic tire having an improved sidewall structure is disclosed, wherein a carcass comprises at least one carcass ply of cords, which comprises an axially innermost part extending through a sidewall potion from a belt edge to the axially inside of a bead core and an axially outermost part extending through the sidewall potion from the belt edge to the axially outside of the bead core, and the rubber thickness measured at the maximum tire section width point in the sidewall portion from the outer surface of the tire to the carcass cords in the axially outermost part being not more than 1.5 times the diameter of the carcass cords but not less than 0.2 mm.

Abstract: A pneumatic radial tire capable of effectively controlling the occurrence of wandering phenomenon when being used in vehicles such as passenger car, small-size truck, truck, bus and the like is provided, in which a second tread zone contacting with a mountain side of a slant road surface is arranged so as to project toward a side of a first tread zone contacting with a flat road surface and camber thrust of the radial tire is increased by the second tread zone during the running on ruts and the like under loading.

Abstract: A pneumatic tire for passenger cars which is improved in harshness noise without deteriorating the steering stability is disclosed, wherein a harshness factor HF is set in the range of from 3.2 to 3.5, the harshness factor HF is: HF=−0.133×(R1/100)+0.245×(R1/R2)−0.183×(Kv/10)+3.898 R1 is a radius of curvature (in mm) of a crown part of the tread profile, R2 is a radius of curvature (in mm) of shoulder parts of the tread profile, and Kv is the vertical spring constant in kN/mm of the tire.

Abstract: A pneumatic tire for passenger cars, having a carcass layer laid between left and right beads, and two belt layers provided in an outer peripheral side of the carcass layer in a tread, wherein a width of a second belt layer counted from the side of the carcass layer is set to 95-110% of a ground contacting width of the tread, a recess being provided in each shoulder so that the center of the recess is positioned in a region separate from a position of the shoulder which corresponds to an edge of the second belt layer toward a relative bead by a distance in the range of 8-14% of a width of the same belt.

Abstract: A new pneumatic radial ply truck tire 10 for use on steering axles has a tread 12 with a pair of centerline grooves 14 and a pair of shoulder grooves 16 that divide the tread 12 into a pair of shoulder rows 24, a pair of riding rows 26 and a center row 28. Lateral grooves 20 divide the rows into block elements 22. The centerline grooves 14 and shoulder grooves 16 have top, middle and bottom potions 30, 32, 34 and 36, 38, 40. The top portions 30, 36 have straight sides 42, 48 that are angled at top angles A1, A2 respectively. The middle portions 32, 38 also have straight sides 44, 50 that are angled at middle angles A3, A4 respectively. To provide the grooves 14, 16 with a general V-shape, it is preferred that the middle angles A3, A4 be greater than their respective top angles A1, A2 respectively. The bottom portions 34, 40 are U-shaped and have bottom widths X1 and bottom depths D1, D2 respectively.

Abstract: A heavy duty radial tire has an aspect ratio of not more than 80% and comprises a radial carcass; a belt comprising a first ply, a second ply and a third ply disposed in this order from the radially inside to the outside; the second ply being widest and the axial width BW thereof being in the range of from 1.00 to 2.00 times the section height H of the tire; a first rubber thickness d1 measured from the first belt ply's edge to the carcass being in the range of from 1.0 to 5.0 mm; a second rubber thickness d2 measured from the third belt ply's edge to the second belt ply being more than the first rubber thickness d1; an axial distance W1 of the first belt ply's edge from the second belt ply's edge and an axial distance W2 of the third belt ply's edge from the second belt ply's edge satisfying the following condition: 0<=W1-W2<=5.

Abstract: A radial motorcycle tire having improved lateral grip under camber with good stability, wherein the tread is reinforced by two main breaker plies comprising parallel reinforcing cords oppositely inclined with respect to the tire circumferential direction and a supplementary breaker ply is disposed radially outward of the main breaker plies and comprises a cord reinforced central ply portion and lateral outer side ply portions disposed on opposite sides of the central ply portion, said lateral side portions comprising rubber having no cord reinforcement.

Abstract: A heavy duty radial tire is provided between the tread edge and the maximum tire width point with a profile which is formed by adding at least a protrusion to a basic profile, the basic profile consisting of an upper line and a lower line, the upper line extending radially inwardly from the tread edge and curved concavely so as to have a center of curvature outside the tire, the lower line extending radially outwardly from the maximum tire width point and curved convexly so as to have a center of curvature inside the tire, the upper line and lower line intersecting each other so as to form an inflection point, the radial height of the inflection point from the bead base line being in the range of from 0.82 to 0.

Abstract: A new pneumatic radial ply truck tire 10 for use on steering axles has a tread 12 with four circumferential grooves 14 that divide the tread 12 into a pair of shoulder rows 24, a pair of riding rows 26 and a center row 28. Lateral grooves 20 divide the rows into block elements 22. The centerline grooves 14 and shoulder grooves 16 have top and bottom potions 30, 32. The top portions 30 have straight sides 42 that are angled at top angles A1. The middle portions 32 also have straight sides 44 that are angled at bottom angles A2. To provide the grooves 14 with a general V-shape, it is preferred that the bottom angles A2 be greater than their respective top angles A1. Stone penetration protectors 34 are positioned within the circumferential grooves 34 to protect the tread 12 and the belt-package 13 from stone damage. The lateral grooves 20 that extend across the two riding rows 26 and the center row 28 have top portions 50 and bottom portions 52.

Abstract: A tire (1), a mounting rim (2) therefor and a circumferentially unstretchable ring (3) for supporting the tread (10) of the tire when running at low or zero pressure. The tire (1) has a radial ply casing (13) on which the points that are furthest apart axially are radially apart close to seats (12B) of outwardly sloping beads (12). The seats (12B) engage sloping seats (23', 23") on the rim (2), which may have at least one mounting well (22), at least one cylindrical portion (21) for receiving the supporting ring (3) and a rim flange (24).

Abstract: A tire having an Heterologous/S form ratio of at least 0.50, having a rad carcass reinforcement (1) and crown reinforcement (3) composed of at least two working crown plies (31,33) made of inextensible metal cables, crossed from one ply to the next, forming angles of between 10.degree. and 45.degree. with the circumferentail direction, and of an additional ply (32) which is axially continuous and formed of metallic elements oriented substantially parallel circumferential direction. Said ply (32) over the working ply (31) radially closest carcass reinforcement (1,) and the ratio of its rigidity of extension per unit of width to the total of the rigidities of extension of the other plies of the crown reinforcement being between 0.35 and 0.70.

Abstract: A very light weight tire 10 has at least one radial ply 38 and a rayon belt structure 36, having two single cut belt layers 50, 51 covered by an overlay 59 having cords 80 selected from the group of aramid, rayon, PEN, PET and PVA. The tire 10 has a very thin or reduced gauge (t) undertead 13. The tire 10 can be made having very low rolling resistance due to the combination of casing structure and the reduced rubber mass.