TWO-WHEEL PNEUMATIC TIRES

Description

[0001] The invention relates to a pneumatic two-wheel tire, preferably a bicycle tire, particularly preferably a racing bike tire, with a tread, a tire carcass, tire sidewalls and two bead areas, each with a tire bead with a core, wherein the two bead areas each have a bead protection band arranged axially outside the carcass as abrasion protection, wherein the tire carcass is formed from a first carcass ply and a second carcass ply, each having strength members,wherein the second carcass ply is arranged radially inside the first carcass ply at a zenith of the pneumatic two-wheel tire and extends from the zenith of the pneumatic two-wheel tire over the tire sidewalls into both bead regions, where it wraps around the respective core from axially inside to axially outside, and ends in a second carcass ply end below the chafer of the respective bead region, and wherein the first carcass ply extends from the zenith of the pneumatic two-wheel tire over the tire sidewalls into the bead regions, where it wraps around the respective core from axially inside to axially outside.

[0002] Conventional pneumatic tires for two-wheelers, preferably bicycle tires, and especially racing bike tires, are designed and optimized for rolling resistance, puncture protection, and mileage. These properties sometimes conflict with one another.

[0003] EP 3174738 A1 discloses a racing bike tire with a two-ply carcass, with the high-cut edges of both carcass layers largely covering the sidewalls. Such a tire has at least a portion of the sidewall reinforced by four carcass layers. This construction provides high cut protection for the sidewall. However, the high use of carcass material in the sidewall area negatively impacts weight and rolling resistance.

[0004] A typical single-ply carcass construction is characterized by the carcass ply's upturns extending to the tire crown and overlapping below the tread. This type of construction is simple to manufacture, but has lower sidewall cut resistance and thus lower puncture resistance.

[0005] The generic DE 202020104281 U1 discloses a tire with a two-ply carcass, with the carcass rollovers of both carcass plies ending below the chafer. The two bead areas each have a chafer arranged on the outside of the carcass to provide abrasion protection.

[0006] Such a tire is optimized in terms of rolling resistance, but has low puncture protection.

[0007] DE 20 2015 000366 U1 discloses a bicycle tire with a tire carcass having two opposing sidewalls, wherein the tire carcass defines a tire interior at least in sections, and wherein a bead with a bead core arranged therein is arranged at the free ends of the sidewalls. An inner side of the tire carcass facing the tire interior is covered with a fabric layer consisting of monofilament threads with a circular cross-section that are embedded in an elastic material or in which the interstices are filled with elastic material. The two ends of the fabric layer are each overlapped by a fabric strip.

[0008] Further bicycle tires are known from WO 2019 / 224714 A1, EP 0 484 831 A1 and WO 2017 / 072708 A1.

[0009] The invention is based on the object of providing a pneumatic two-wheel tire, preferably a bicycle tire, particularly preferably a racing bike tire, in which the puncture resistance is improved while still maintaining good rolling resistance.

[0010] The problem is solved in that the first carcass ply is guided from the respective bead area in a first carcass ply turn-up over the respective tire sidewall to under the tread to a first carcass ply end and ends there in the first carcass ply end.

[0011] One advantage of the pneumatic two-wheel tire according to the invention, preferably the bicycle tire, particularly preferably the racing bike tire, is that the new tire construction significantly improves puncture resistance. At the same time, the tire exhibits good rolling resistance.

[0012] Essential to the invention is that the first carcass ply is guided from the respective bead area in a first carcass ply turn-up over the respective tire sidewall to under the tread to a first carcass ply end, where it terminates under the tread at the respective first carcass ply end. At the same time, the second carcass ply ends already under the chafer and is thus not guided from the respective bead area over the tire sidewalls to under the tread.

[0013] The tire has two axial halves. Thus, in both axial halves of the tire, in a region of the sidewall, particularly radially between the second carcass ply end and one tread end, the sidewall is reinforced by three carcass ply thicknesses, with the first carcass ply contributing two ply thicknesses and the second carcass ply contributing one ply thickness. Reinforcement by three ply thicknesses significantly improves the cut resistance of the sidewall compared to a carcass with sidewall reinforcement by only two ply thicknesses.

[0014] While reinforcing the sidewall with three carcass plies results in increased friction loss and requires additional carcass material, the trade-off between sidewall puncture resistance and high rolling resistance is resolved in favor of puncture resistance.

[0015] The rolling resistance and the driving characteristics of such a tire according to the invention are in particular better than those of a tire with a reinforcement of the sidewall by four ply thicknesses of the carcass while still maintaining good puncture resistance.

[0016] By locating the first carcass ply ends beneath the tread, they are also protected from detachment. This further improves the durability and puncture resistance of the two-wheel tire.

[0017] The new construction, with its two carcass plies wrapped around the core, allows for continued simple tire construction and also provides advantageous protection of the core from damage, especially compared to a carcass with only one carcass ply.

[0018] It has thus been found that a two-wheel tire, preferably a bicycle tire, particularly preferably a racing bike tire, having the new construction resolves the conflict of objectives between puncture resistance, in particular puncture resistance of the sidewall, and rolling resistance at a high level in favor of puncture resistance.

[0019] At the same time, the new design, by arranging the second carcass ply ends under the respective chafer, ensures that there is no direct connection between the tire interior and the tire exterior through either of the two carcass plies. Likewise, the reinforcement members of the second carcass ply ending there are covered from the outside by the chafer at the second carcass ply ends. This prevents or greatly reduces the risk of air being blown out of the tire interior through the two carcass plies, particularly during tubeless operation, thus ensuring a high level of airtightness of the tire, especially during tubeless operation.

[0020] The first carcass ply terminates at the first carcass ply ends below the tread. The first carcass ply ends can thus be spatially arranged between the tread and the second carcass ply, as well as radially outside and axially inside the tread ends of the tread. A first straight line oriented perpendicular to the second carcass ply can connect the tread and the first carcass ply end.

[0021] The second carcass ply terminates at the second carcass ply ends below the chafer of the respective bead area. The second carcass ply ends can thus each be spatially arranged between the respective chafer and the respective first carcass ply turnup in the bead area. A second straight line oriented perpendicular to the first carcass ply turnup can connect the chafer and the second carcass ply end.

[0022] The chafer serves as abrasion protection against the rim flange during tire operation, thus reducing exposure of the carcass reinforcements. The chafer may form or co-form an outer surface of the bead area designed as a contact surface with the rim. The chafer may cover the respective second carcass ply end from the outside.

[0023] The first carcass ply and the second carcass ply each have parallel reinforcements embedded in elastomeric material. As usual, the reinforcements can form an angle of 40 degrees to 60 degrees with the direction of rotation U. The reinforcements of the first carcass ply and the second carcass ply have opposing pitch angles.

[0024] Advantageous further developments of the invention are explained below.

[0025] The tire has two axial halves. In an advantageous embodiment of the invention, each first carcass ply end is arranged below the tread in that axial half of the tire in which the first carcass ply is guided in the first carcass ply turnup over the tire sidewall to below the tread to the respective first carcass ply end.

[0026] The first two carcass ply turnups thus do not overlap at the tire's zenith. The first carcass ply ends are each located in the same axial half as the first carcass ply turnup, which ends in the respective first carcass ply end. The first carcass ply turnups are thus limited to the respective axial half of the tire. Axially between the first two carcass ply ends of the first carcass ply, reinforcement is provided by exactly two ply thicknesses of the carcass.

[0027] This provides a pneumatic two-wheel tire that ensures advantageous puncture protection of the sidewalls with minimal use of carcass material, especially at the tire's zenith. Such a tire exhibits particularly low rolling resistance.

[0028] In particular, each first carcass ply end is arranged in that axial half of the tire below a tread run-out of the tread in which the first carcass ply is guided in the first carcass ply turn-up over the tire sidewall to under the tread to the respective first carcass ply end and ends in the first carcass ply end arranged below the tread run-out.

[0029] This further optimizes rolling resistance by further reducing the use of overlapping carcass material. At the same time, cut protection in the sidewall area is still ensured and the first carcass ply ends are protected from detachment.

[0030] The first carcass ply then terminates at the first carcass ply ends below the tread runout. The first carcass ply ends can thus be spatially arranged between the tread runout and the second carcass ply, as well as radially outside and axially inside the tread ends of the tread. A first straight line oriented perpendicular to the second carcass ply can connect the tread runout and the first carcass ply end.

[0031] The tread runout may extend in each axial half of the tire from the respective tread end by a maximum of 10 mm, preferably a maximum of 2 mm, axially inward, measured along a radially inner boundary of the tread.

[0032] In an alternative advantageous development of the invention, it is provided that the two first carcass ply upturns are arranged overlapping one another in the zenith of the tire.

[0033] Each of the first two carcass ply turnups extends from a bead area in one axial half of the tire to below the tread and terminates in the respective first carcass ply end in the other axial half of the tire. At the tire's zenith, the tire is thus reinforced by four carcass ply thicknesses, with the first carcass ply contributing three ply thicknesses and the second carcass ply contributing one ply thickness.

[0034] While such a design may have a negative impact on rolling resistance, the tire's cut protection in the tread area is significantly improved, further improving puncture resistance. This is particularly important for all-season tires and training tires for road bikes.

[0035] In an advantageous development of the invention, it is provided that the chafer ends in a radially outer end at a first height of a maximum of 15 mm, preferably from 10 mm to 12 mm, measured relative to an outermost turning point of the reinforcement members of the second carcass ply wrapped around the core.

[0036] This low arrangement of both the chafer and the associated low arrangement of the second carcass ply ends means that the turn-ups of the second carcass plies are primarily located in an area that experiences little or no cyclic deformation during tire operation. This further reduces energy loss due to friction in the second carcass ply. Likewise, the material used for the chafer and the second carcass ply, and thus the tire's weight, is advantageously reduced.

[0037] To determine a height in the bead area, in particular the first height or the second height mentioned below, the cross-section of the pneumatic two-wheel tire can be bent up in such a way that the two carcass plies, coming from the zenith, are arranged largely in a straight line in the area of ​​the sidewall and merge into a wrap around the core that is largely symmetrical with respect to the core. In this arrangement, the respective height is measured relative to the outermost turnover point of an outer edge of the reinforcement members of the second carcass ply wrapped around the core, measured parallel to the largely straight-line arranged carcass plies. If the chafer has fibers, in particular a fabric, the fibers, in particular the fabric edge of the fabric, can specify the radially outer end of the chafer.Accordingly, the first carcass ply end and the second carcass ply end can be provided by ends of the reinforcement members, in particular by a fabric edge, of the respective carcass ply.

[0038] Corresponding advantages with regard to the second carcass ply can be achieved in that the second carcass ply ends are arranged at a second height of a maximum of 13 mm, preferably from 8 mm to 10 mm, below the chafer, measured relative to an outermost turning point of the reinforcement members of the second carcass ply wrapped around the core.

[0039] Corresponding advantages also arise if the second carcass insert ends end in the respective bead area, especially coming from the core in front of the sidewall.

[0040] The chafer strip can be designed as a rubberized strip comprising fibers, in particular as a rubberized fabric strip. The fabric strip can be a muslin or nylon fabric.

[0041] In a further advantageous development of the invention, it is provided that the chafer is free of threads comprising twisted fibers which connect a radially outer end of the chafer and an inner end of the chafer.

[0042] In a further advantageous development of the invention, it is provided that the chafer is designed as a rubberized monofilament fabric.

[0043] The rubberized monofilament fabric is particularly effective at reducing air leakage at the tire-rim contact area, particularly more effectively than a conventional chafer with a fabric made up of multiple twisted fibers. This is because the monofilaments are largely individually embedded in the rubber coating, thus largely preventing air from escaping from the tire's interior to the tire's exterior via microchannels between the fibers of the chafer's threads.

[0044] This allows for particularly good airtightness of the tire mounted on a rim. This is particularly advantageous for tubeless tires. This allows the tire to be used without a tube without the need for additional, complex measures such as an inner liner, which often increase rolling resistance.

[0045] The chafer designed as a rubberized monofilament fabric may be free of threads comprising twisted fibers that connect a radially outer end of the chafer and an inner end of the chafer.

[0046] In a further advantageous development of the invention, the carcass is in direct contact with the tire interior. This allows for a particularly lightweight tire and thus advantageous rolling resistance. For a tubeless tire, especially a "tubeless ready" bicycle tire, sufficient airtightness can be ensured by the described measures, in particular the design of a chafer made of rubberized monofilament fabric.

[0047] In a further advantageous development of the invention, it is provided that the tire is a tubeless tire, in particular a "tubeless" tire or a "tubeless ready" tire.

[0048] Tubeless tires are tires that are suitable for tubeless operation. Tubeless tires are specifically tires for tubeless operation. Tubeless tires place increased demands on the airtightness of both the tire itself and the seal at the contact surface between the tire and the rim. A system for tubeless operation therefore comprises at least the tubeless tire and a rim, with the tubeless tire mounted on the rim and the system being free of an inner tube. In tubeless operation of the tubeless tire, friction losses between the inner tube and tire are eliminated, so that the tire offers advantageous rolling resistance. Tube-related puncture causes are also eliminated. When a tubeless tire is used in tubeless operation, the use of a sealing fluid, particularly a sealing milk, which is filled into the tire interior between the tire and rim can improve the seal.

[0049] A tubeless tire can be a so-called "tubeless" tire, which is primarily or exclusively suitable and intended for use without an inner tube. A tubeless tire can often also be used without sealant.

[0050] A tubeless tire can also be a so-called "tubeless ready" tire, which is suitable and intended for use with or without a tube. A tubeless ready tire is typically used in tubeless mode with a sealing fluid, especially a sealant. The tire and rim can be designed to seal directly against each other.

[0051] The invention is particularly advantageous for tubeless bicycle tires, in particular tubeless racing bike tires or tubeless mountain bike tires.

[0052] In a further advantageous development of the invention, it is provided that the bicycle tire is suitable and intended for operation with a tube, in particular a clincher tire. A system for operation with a tube thus comprises at least the bicycle tire and a rim, wherein the bicycle tire is mounted on the rim and a largely airtight tube is arranged in a tire interior enclosed by the tire and the rim. In a tire used with a tube, the air pressure is maintained via a largely airtight tube arranged in the tire interior between the tire and rim. Here, too, the new tire construction enables advantageously reduced rolling resistance.

[0053] A so-called clincher tire is usually a wire or folding tire. The tire has a wire or folding core and is attached to the rim flange by the bead. A clincher tire is easy to install and remove. In the event of a puncture, the damage can be easily repaired.

[0054] In a further advantageous development of the invention, it is provided that, at least in one region of the sidewall, the two carcass plies, i.e., the first carcass ply and the second carcass ply, are the only plies containing reinforcements. By omitting a further reinforcement ply, a particularly thinner and thus lighter, rolling-resistance-optimized region of the sidewall is possible.

[0055] In a further advantageous development of the invention, it is provided that a damping rubber insert made of a highly elastic rubber is arranged between the tread and the tire carcass, wherein the damping rubber insert has in particular a material thickness between 0.2 mm and 1 mm.

[0056] This allows for greater riding comfort and improved rolling resistance by decoupling the fabric layers. The special thickness of the cushioning rubber insert significantly improves the riding comfort of the bicycle tire, as the tire adapts better to the road surface. Furthermore, the additional rubber insert increases puncture protection at the zenith.

[0057] Preferably, the damping rubber insert can be made of a highly elastic rubber with a rebound material value between 70 and 80. This rebound material value achieves optimal driving comfort while at the same time not increasing the rolling resistance of the tire.

[0058] In a further advantageous development of the invention, it is provided that a protective layer comprising a particularly tear-resistant, tear-resistant rubberized fabric, preferably a particularly tear-resistant rubberized fabric comprising fibers made of polyethylene terephthalate - polyacrylate, or of a rubber layer is arranged between the tread and the tire carcass.

[0059] The protective layer ensures optimal puncture protection at the zenith of the pneumatic two-wheel tire, preferably a bicycle tire, and especially preferably a racing bike tire. The particularly tear-resistant rubberized fabric comprising polyethylene terephthalate-polyacrylate fibers can be a rubberized fabric containing or consisting of Vectran fibers. The rubber layer can have a maximum thickness of 6 mm, measured radially at the tire zenith.

[0060] In a further advantageous development of the invention, it is provided that the tire is a bicycle tire, in particular a racing bike tire, a mountain bike tire, or a tire for a bicycle having an electric motor for driving the bicycle. However, the new tire construction is suitable for use in all bicycle segments.

[0061] The new tire construction is particularly advantageous for racing bike tires, as it significantly reduces rolling resistance. A racing bike tire typically has a maximum tire width of 35 mm and features a low tread profile specific to racing bikes.

[0062] The new tire construction, especially for tubeless tires, is also ideal for mountain bike tires. Mountain bike tires typically have a minimum tire width of 35 mm, especially 40 mm, and often feature a pronounced tread pattern. Aspects such as rolling resistance are also becoming increasingly important for mountain bike tires. Tubeless tire operation can be particularly advantageous, as it reduces the risk of punctures and allows for use with such tires at comparatively lower air pressure.

[0063] The new tire design is also ideal for use on bicycles equipped with an electric motor. Low rolling resistance is advantageous in such applications, as it increases the range of the bicycle.

[0064] This could be a tire for an electric bike. A tire for an electric bike can meet the "ECE-R75" test standard. The specific suitability for electric bikes is often indicated by the designation "E-bike ready 50."

[0065] This can also be a tire for a pedelec, where the drive is at least partially assisted by the electric motor. The special suitability for a pedelec is often indicated by the designation "E-bike ready 25."

[0066] In a further advantageous development of the invention, it is provided that the tire is a motorcycle tire, in particular an electric scooter tire. A motorcycle tire or an electric scooter tire featuring the novel design can also contribute to an improved range of the vehicle through the advantageous rolling resistance.

[0067] Further features, advantages and details of the invention will now be explained in more detail with reference to the schematic drawings, which illustrate exemplary embodiments, as well as comparative data. Fig. 1 and 2: a cross-sectional view of a pneumatic two-wheel tire; Fig. 3: a section of a two-wheel tire in cross-section.

[0068] The Figures 1 and 2Each shows the essential tire components of a two-wheel tire 1 in a cross-sectional view. It is a pneumatic two-wheel tire 1, preferably a bicycle tire, particularly preferably a racing bike tire 1, with a tread 2, a tire carcass, tire sidewalls 3, and two bead regions 4, each with a tire bead with a core 5, wherein the two bead regions 4 each have a chafing protection band 8 arranged axially outside the carcass as abrasion protection.

[0069] The tire carcass is formed from a first carcass ply 6 and a second carcass ply 6', each comprising reinforcement members. The reinforcement members are arranged parallel to one another within the respective carcass ply and at an angle to the circumferential direction U of 40 degrees to 60 degrees. The reinforcement members of the two carcass plies 6, 6' have opposing pitch angles. The tire 1 has two axial halves 20, which are symmetrical to one another, at least with respect to the carcass plies 6, 6'.

[0070] The second carcass ply 6' is arranged at a zenith 17 of the tire 1, radially inside the first carcass ply 6. It extends from the zenith 17 of the pneumatic two-wheel tire 1 over the tire sidewalls 3 into both bead regions 4, where it wraps around the respective core 5 from axially inside to axially outside, terminating in a second carcass ply end 7' beneath the chafer 8 of the respective bead region 4.

[0071] The first carcass ply 6 extends from the zenith 17 of the tire 1 over the tire sidewalls into the bead areas 4 and wraps around the respective core from axially inside to axially outside.

[0072] The two-wheel tire is characterized in that the first carcass ply 6 is guided from the respective bead region 4 in a first carcass ply turnup 61 over the respective tire sidewall 3 to under the tread to a first carcass ply end 7 and ends there under the tread 2 in the first carcass ply end 7. Thus, in both axial halves of the tire, in a region of the sidewall 3, in particular radially between the second carcass ply end 7' and a tread end 21, the sidewall 3 is reinforced by three ply thicknesses of the carcass, with the first carcass ply 6 contributing two ply thicknesses and the second carcass ply 6' contributing one ply thickness.

[0073] The first carcass ply 6 terminates in the first carcass ply ends 7 below the tread 2. The first carcass ply ends 7 can thus each be spatially arranged between the tread 2 and the second carcass ply 6', as well as radially outside and axially inside the tread ends 21 of the tread. A first straight line 18 oriented perpendicular to the second carcass ply 6' can connect the tread 2 and the first carcass ply end 7 to one another.

[0074] The second carcass ply 6' terminates in the second carcass ply ends 7' below the chafer 8 of the respective bead region 4. The second carcass ply ends 7' can thus each be spatially arranged between the respective chafer 8 and the respective first carcass ply turnup 61 in the bead region 4. A second straight line 19 oriented perpendicular to the first carcass ply turnup 61 can connect the chafer 8 and the second carcass ply end 7' to one another.

[0075] The chafer 8 can terminate in a radially outer end 12 at a first height 13 of a maximum of 15 mm, preferably from 10 mm to 12 mm, measured relative to an outermost turn-over point 14 of an outer edge of the reinforcements of the second carcass ply 6' wrapped around the core 5. Alternatively or additionally, the second carcass ply ends 7' of the second carcass ply 6' can be arranged at a second height 15 of a maximum of 13 mm, preferably from 8 mm to 10 mm, measured relative to an outermost turn-over point 14 of the reinforcements of the second carcass ply 6' wrapped around the core 5. Dimensioning of the first height 13 and the second height 15 is shown in the Fig. 3 The chafer strip 8 is designed as a rubberized strip comprising fibers, in particular as a rubberized fabric strip.

[0076] The fibers, in particular the fabric edge of the fabric, can define the radially outer end 12 of the chafer 8. In particular for tubeless operation, the chafer 8 can be free of threads having twisted fibers that connect a radially outer end 12 of the chafer 8 and an inner end 16 of the chafer 8. In the Figures 1 and 2 The chafer strip 8 is designed as a rubberized monofilament fabric.

[0077] The second carcass ply ends 7' of the second carcass ply 6' can end in the bead area 4, in particular coming from the core 5 in front of the sidewall 3.

[0078] The carcass is in direct contact with the tire interior 10. The tire 1 is, in particular, free of an inner liner. However, advantages according to the invention can also be achieved by a tire 1 that has an additional layer, in particular an inner liner, between the tire interior 10 and the carcass.

[0079] As shown, at least in one region of the sidewall 3, in particular from the radial outside adjoining the bead band 8, the two carcass inserts 6, 6' can be the only inserts having reinforcements.

[0080] As shown, a damping rubber insert 9 made of a highly elastic rubber can be arranged between the tread 2 and the tire carcass. The damping rubber insert 9 preferably has a material thickness between 0.2 mm and 1 mm. The damping rubber insert can preferably be made of a highly elastic rubber with a rebound material value between 70 and 80.

[0081] A protective layer (not shown) comprising a particularly tear-resistant rubberized fabric, preferably a rubberized fabric comprising polyethylene terephthalate-polyacrylate fibers, can be arranged between the tread 2 and the tire carcass. Alternatively, the protective layer can also be formed from a rubber layer with a maximum thickness of 6 mm, measured in the radial direction rR at the tire zenith 17.

[0082] The tires shown are tubeless tires, specifically "tubeless" tires or "tubeless ready" tires. The tire may be suitable, intended, and used for tubeless operation. However, a tire designed for use with a tube, specifically a clincher tire, may also have an advantageous design with corresponding features.

[0083] The tires depicted are racing bike tires. However, other tires, particularly mountain bike tires or tires for bicycles with an electric motor for driving the bicycle, can also be designed accordingly. Motorcycle tires, particularly electric scooter tires, can also feature the advantageous design depicted.

[0084] The embodiments of the Figure 1 and Figure 2 differ in the extension of the first carcass ply turn-ups 61 and the arrangement of the first carcass ply ends 7 under the tread 2: The Figure 1shows a tire 1 with particularly low rolling resistance. Each first carcass ply end 7 is arranged in that axial half 20 of the tire 1 under the tread 2, in particular as shown under a tread runout 22 of the tread, in which the first carcass ply 6 is guided in the first carcass ply turnup 61 over the tire sidewall 3 to under the tread 2 to the respective first carcass ply end 7. The tread runout 22 extends in the respective axial half 20 of the tire from the respective tread end 21 a maximum of 10 mm, preferably a maximum of 2 mm, axially inward to an axially inner tread runout 23, measured along a radially inner boundary of the tread.

[0085] The two first carcass ply turnups 61 thus do not overlap at the zenith 17 of the tire 1. The first carcass ply ends 7 are each arranged in the same axial half 20 as the first carcass ply turnup 61 that ends in the respective first carcass ply end 7. The first carcass ply turnups 61 are thus arranged in a manner limited to the respective axial half 20 of the tire.

[0086] The Figure 2 shows a particularly puncture-proof tire 1. In contrast to the Figure 1In the tire shown, the two first carcass ply turnups 7 are arranged overlapping one another at the zenith 17 of the tire 1. Each of the two first carcass ply turnups 61 extends from a bead region 4 in one axial half 20 of the tire to below the tread 2 and ends in the respective first carcass ply end 7 in the other axial half 20 of the tire. Thus, as shown, at the zenith 17 of the tire, the tire 1 is reinforced by four ply thicknesses of the carcass.

[0087] The Fig. 3clarifies the dimensioning of the first height 13 and the second height 15. To determine the first height 13 and the second height 15, the two-wheel pneumatic tire 1 can be bent in its cross-section so that the two carcass inserts 6, 6' coming from the zenith 17 are arranged largely in a straight line in the area of ​​the sidewall 3 and merge into a largely symmetrical wrap around the core 5 with respect to the core 5. This can be a section of the tire of the Fig. 1 , wherein the two-wheel pneumatic tire 1 is bent up accordingly in its cross-section. In this arrangement, the first height 13 and the second height 15 are measured relative to the outermost turning point 14 of an outer edge of the reinforcement members of the second carcass ply 6' wrapped around the core 5 and measured parallel to the carcass plies 6, 6' arranged largely rectilinearly in the region of the sidewall 3. Try

[0088] Tests were carried out with four different tubeless racing bike tires. The tires R1 according to the invention, designed according to Figure 1 , and R2, designed according to Figure 2 , was tested. A reference tire, the RR3, was also tested, which was largely identical in construction to the R1 tire. However, unlike the R1 tire, the first carcass ply ends below the respective chafer. The same components were used for the R1, R2, and RR3 tires except for the carcass structure. A standard racing tubeless tire with exactly one carcass ply was also tested as the RR4 reference tire, with the carcass ply rolls overlapping each other at the zenith. The RR4 reference tire also has an inner liner to ensure sufficient airtightness. The results are summarized in Table 1. Table 1 Tires R1 R2 RR3 RR4 Weight [g] 243 263 213 296 Rolling resistance [W] 13,4 16,3 12,6 16,2 Number of reinforcement layers in the sidewall 3 3 2 2 Cut protection side wall [N] 448 446 331 346 Number of reinforcement layers at the zenith 2 4 2 3 Cut protection Zenit [N] 725 1265 775 1219

[0089] The weight difference between the R1, R2, and RR3 tires is solely due to the different lengths of the first carcass ply. Despite its single-ply carcass, the RR4 tire is heavier than the other tires due to the inner liner layer. Accordingly, the weight of the tires increases in the order RR3, R1, R2, and RR4.

[0090] Rolling resistance was measured at a maximum pressure of 7.5 bar on a 19C rim without a tube or sealant. This demonstrates the influence of energy loss due to friction between reinforcement layers. The reference tire, with the least amount of casing material and the lowest weight, also exhibits the lowest rolling resistance. The R1 tire, with only one additional ply thickness in the sidewall, exhibits slightly higher rolling resistance. The two tires R2 and RR4 exhibit the highest rolling resistance, with the rolling resistance of the R2 tire being roughly the same as that of the standard tubeless RR4 tire with a single casing ply.

[0091] Cut protection was tested using force measurements when a blade (comparable to stones on the road) punctures the tire's zenith and the sidewall. The number of reinforcing layers plays a significant role in the blade measurements. Accordingly, the cut protection in the sidewall area of ​​the two tires R1 and R2 is approximately 30% higher than the cut protection of the reference tires RR3 and RR4. At the zenith, the highest cut protection is provided by the R2 tire, which has reinforcement in the zenith by four layer thicknesses. The reference tire RR4 offers slightly lower cut protection at the zenith. The R1 and RR3 tires, which only have two layers of reinforcement in the zenith, have the lowest cut protection at the zenith.

[0092] It can thus be seen that the tires R1 and R2 according to the invention resolve the conflict between puncture resistance of the sidewall and high rolling resistance in favor of puncture resistance of the sidewall. Even the tire R2, with the highest puncture protection in the sidewall and at the crown, exhibits a rolling resistance only at the level of the reference tire RR4. List of reference symbols

[0093] 1Two-wheel pneumatic tire 2Tread 3Sidewall 4Bead area 5Core 6First carcass ply 6Second carcass ply 7First carcass ply end 7Second carcass ply end 8Chafer 9Rubber insert 10Tire interior 11Tire exterior 12Radial outer end of the chafer 13First height 14Outermost turn-over point 15Second height 16Inner end 17Cenith 18First straight line 19Second straight line 20Axial half 21Tread end 22Tread run-out 23Tread run-out rRradial direction aRaxial direction UCircular direction

Claims

1. Two-wheeled vehicle pneumatic tire (1), preferably bicycle tire, particularly preferably racing bike tire, having a tread (2), having a tire carcass, having tire sidewalls (3) and having two bead regions (4) which each have a tire bead with a core (5), wherein the two bead regions (4) each have, as an anti-chafing guard, a bead protective strip (8) arranged axially outside the carcass, • wherein the tire carcass is formed from a first carcass inlay (6) and a second carcass inlay (6'), each comprising strength members, wherein the first carcass inlay and the second carcass inlay each have strength members which run parallel to one another and which are embedded in elastomer material, wherein the strength members of the first carcass inlay and of the second carcass inlay have opposing angles of inclination, • wherein the second carcass inlay (6') is arranged, radially to the inside of the first carcass inlay (6), in a crown (17) of the two-wheeled vehicle pneumatic tire (1), extends from the crown (17) of the two-wheeled vehicle pneumatic tire (1) over the tire sidewalls (3) into the two bead regions (4), loops there around the particular core (5) from axially inside to axially outside, and terminates at a second carcass inlay end (7') under the bead protective strip (8) of the particular bead region (4), and • wherein the first carcass inlay (6) extends from the crown (17) of the two-wheeled vehicle pneumatic tire (1) over the tire sidewalls (3) into the two bead regions (4), and loops there around the particular core (5) from axially inside to axially outside, characterized in that • proceeding from the particular bead region (4), the first carcass inlay (6) is guided with a first carcass inlay turn-up (61) over the particular tire sidewall (3) as far as under the tread (2) to a first carcass inlay end (7), and terminates there at the first carcass inlay end (7).

2. Two-wheeled vehicle pneumatic tire (1) according to Claim 1, characterized in that the tire (1) has two axial halves (20), and in that each first carcass inlay end (7) is arranged under the tread (2), in particular under a tread runout (22) of the tread, in each case in that axial half (20) of the tire (1) in which the first carcass inlay (6) is guided with the first carcass inlay turn-up (61) over the tire sidewall (3) as far as under the tread (2) to the particular first carcass inlay end (7).

3. Two-wheeled vehicle pneumatic tire (1) according to Claim 1, characterized in that the two first carcass inlay turn-ups (7) are arranged so as to overlap one another in the crown (17) of the tire (1).

4. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the bead protective strip (8) terminates at a radially outer end (12) at a first height (13) of at most 15 mm, preferably of 10 mm to 12 mm, as measured relative to an outermost turning point (14) of the strength members of the second carcass inlay (6') that are looped around the core (8).

5. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the bead protective strip (8) is designed as a rubberized monofilament fabric.

6. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the carcass is in direct contact with a tire interior (10).

7. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the tire is a tube-free tire (1), in particular a "tubeless" tire or a "tubeless ready" tire.

8. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the tire is a bicycle tire (1) for operation with a tube, in particular a clincher tire.

9. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that at least in one region of the sidewall (3), the first carcass inlay (6) and the second carcass inlay (6') are the only inlays comprising strength members.

10. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that a damping rubber inlay (9) composed of a highly elastic rubber is arranged between the tread (2) and the tire carcass, wherein the damping rubber inlay (9) has in particular a material thickness between 0.2 mm and 1 mm.

11. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that a protective ply composed of an in particular tear-resistant rubberized fabric, preferably an in particular tear-resistant rubberized fabric comprising fibers composed of polyethylene terephthalate polyacrylate, or composed of a rubber layer, is arranged between the tread (2) and the tire carcass.

12. Two-wheeled vehicle pneumatic tire (1) according to at least one of the preceding claims, characterized in that the tire is a bicycle tire (1), in particular a racing bike tire (1), a mountain bike tire or a tire for a bicycle having an electric motor for driving the bicycle.