Bicycle tire

Abstract

The invention relates to a bicycle tire having a tire carcass and a tread provided for contact with the road, at least portions of the tire carcass defining a tire interior, the tire carcass having two side walls and a tire bead in the region of each free end of the side walls, the carcass threads, in particular the warp threads, of a woven carcass fabric of the tire carcass assuming, at the point of intersection with a central plane of the tire, an angle between 55° and 85° or an angle between -55° and -85° with respect to the central plane, and at least one side-wall reinforcement being located in the region of each of the side walls of the tire carcass.

Description

[0001] bicycle tires

[0002] The invention relates to a bicycle tire with a tire carcass and a tread provided for contact with the road surface, wherein the tire carcass defines at least a section of the tire interior and has two sidewalls and a tire bead in the area of ​​the respective free end of the sidewalls.

[0003] The invention is intended to improve a bicycle tire.

[0004] According to the invention, a bicycle tire with the features of claim 1 is provided for this purpose. Advantageous embodiments of the invention are mentioned in the dependent claims.

[0005] In a bicycle tire with a tire carcass and a tread intended for road contact, wherein the tire carcass defines at least a section of the tire interior and has two sidewalls and a tire bead in the area of ​​the respective free end of the sidewalls, it is provided that the carcass threads, in particular the warp threads, of a carcass fabric of the tire carcass at the intersection with a median plane of the tire assume an angle between 55° and 85° or an angle between -55° and -85° to the median plane and that at least one sidewall reinforcement is arranged on the tire carcass in the area of ​​the sidewalls.

[0006] The carcass threads of the tire carcass fabric intersect the tire's midplane at an angle known as the carcass zenith angle, the magnitude of which lies between 55° and 85° and whose sign can be positive or negative. The carcass fabric is typically a cord weave, and the warp threads of this fabric are referred to as carcass threads.

[0007] Compared to conventional bicycle tires, where the angle of the carcass cords to the tire's central plane, also known as the carcass zenith angle, lies between 30° and 45°, the properties of the bicycle tire according to the invention are significantly different. Specifically, the forces introduced into the tire can deform it over a considerably smaller area than with conventional bicycle tires, which reduces the counterforce due to the tire's internal pressure. As a result, obstacles such as roots, stones, curb edges, and the like can deform the tire carcass more easily, thus enabling a significantly more comfortable ride. The tire's suspension travel is, in effect, better utilized. Furthermore, the tire according to the invention better hugs obstacles, maintaining greater ground contact, which leads to significantly increased traction, especially in off-road use.

[0008] Conventional bicycle tires have a carcass zenith angle between 30° and 45°, since the lateral stiffness of the tire is very low with a carcass zenith angle between 55° and 85° according to the invention. Unlike car and motorcycle tires, it is not possible to compensate for these disadvantages of the "quasi-radial construction" with a zenith angle between 55° and 85° in bicycle tires by massively reinforcing the tire carcass, as the tire would otherwise be far too heavy for use as a bicycle tire and the rolling resistance would also be far too high. According to the invention, a sidewall reinforcement is therefore provided. This sidewall reinforcement is only provided in the area of ​​the sidewalls on the tire carcass. This makes it possible to compensate for the disadvantages of the carcass zenith angle between 55° and 85° according to the invention without increasing the weight of the tire excessively.

[0009] In a further development of the invention, the carcass threads, in particular the warp threads, of the carcass fabric of the tire carcass have an angle of 70° to 80°, in particular 75°, or -70° to -80°, in particular -75°, at the intersection with the central plane of the tire.

[0010] Such an angle value between 70° and 80°, in particular 75°, with a positive or negative sign, has proven to be particularly advantageous.

[0011] In a further development of the invention, the tire carcass has several layers of fabric at the intersection with the central plane of the tire, wherein the warp threads of at least two layers of fabric of the tire carcass cross each other, wherein the layers of fabric of the tire carcass with intersecting warp threads lie directly on top of each other or are separated by only one further layer of fabric.

[0012] For example, successive layers of fabric in the tire carcass have a carcass zenith angle of 75°, then -75° and then 75° again.

[0013] In a further development of the invention, the side wall reinforcement covers between one quarter and four quarters, in particular two thirds, of the surface of the respective side wall.

[0014] It has been found that a sidewall reinforcement covering only between one-quarter and four-quarters, and in particular two-thirds, of the respective sidewall surface is sufficient to increase the lateral stiffness of the tire to such an extent that it can be used without problems as a bicycle tire. Each sidewall of the tire extends from the respective tire bead to the tread intended for road contact. However, within the scope of the invention, the entire sidewall can also be covered by the sidewall reinforcement.

[0015] In a further development of the invention, the side wall reinforcement has at least one layer and a maximum of four layers, in particular two or three layers, of rubberized fabric.

[0016] Within the scope of the invention, the side wall reinforcement can be made from a cross-woven fabric in which the same number and spacing of warp threads and weft threads are provided. In a further development of the invention, the side wall reinforcement comprises two, three, or four layers of rubberized fabric, wherein the warp threads have an angle between 40° and 50° or between -40° and -50°, in particular +45° or -45°, and the warp threads of the layers, in particular the warp threads of directly adjacent layers, cross each other, in particular at an angle of 90 degrees.

[0017] For example, the sidewall reinforcement has a warp thread angle of +45° in the first layer, -45° in the second layer, and +45° in the third layer. It has been found that a sidewall reinforcement in which the threads of directly adjacent layers cross over each other provides very good sidewall stiffening at a low weight. For effective sidewall stiffening, it is essential that the warp threads of the fabric layers of the sidewall reinforcement have an angle of no more than +50° or -50°, and in particular no more than +45° or -45°.

[0018] In a further development of the invention, the side wall reinforcement has at least one layer, in particular two or three layers, of a rubber layer.

[0019] Within the scope of the invention, for example, one or more layers of fabric can be combined with one or more layers of a rubber layer.

[0020] In a further development of the invention, the sidewall reinforcement comprises several layers of fabric and / or rubber, wherein the lowest layer, or the innermost layer of the sidewall reinforcement, has the greatest extent in the direction from the tire bead to the tread of the bicycle tire, and wherein the subsequent layers arranged on top of the lowest layer are each shorter than the layer below it, resulting in a, in particular step-like, decrease in the tire's material thickness from the tire bead to the tread. In other words, the multiple layers of the sidewall reinforcement terminate in steps on the tread side. The layers of the sidewall reinforcement are typically located between the layers of the tire carcass, so that the tire thickness decreases in the sidewall area from the tire bead to the tread.This also results in a decrease in the stiffness of the sidewall reinforcement from the tire bead to the tread, which contributes to the positive properties of the bicycle tire according to the invention. Specifically, the bicycle tire according to the invention is sufficiently stiff in the sidewall area to allow for easy riding, while in the tread area it is significantly less stiff than a conventional bicycle tire, thus enabling a considerably more comfortable ride or significantly better ground contact when riding over obstacles.

[0021] In a further development of the invention, a puncture protection belt made of at least one first layer of fabric is arranged between the tire carcass and the tread, wherein the first layer lies directly on the tire carcass and wherein the warp threads of the fabric of the puncture protection belt at the intersection with the central plane of the tire form an angle between 55° and 85°, in particular between 70° and 80°, in particular 75°, or an angle between -55° and -85°, in particular -70° to -80°, in particular -75°.

[0022] The angle of the warp threads of the puncture protection belt fabric is therefore between 55° and 85°, particularly between 70° and 80°, and especially 75°, in all layers of the puncture protection belt fabric, whereas the sign of the angle can be positive or negative. The angle of the warp threads of the puncture protection belt fabric is thus in the same angular range as the angle of the warp threads of the tire carcass. This allows a puncture protection belt to be provided to ensure increased puncture protection, while maintaining the improved spring properties of the tire in the tread area. In particular, according to the invention, the angle of the warp threads of the puncture protection belt fabric at the intersection with the central plane of the tire can be equal to the angle of the carcass threads of the carcass fabric at the intersection with the central plane of the tire.Within the scope of the invention, the angle of the warp threads of the puncture protection belt fabric does not necessarily have to be the same as the angle of the carcass threads of the carcass fabric; for example, the angle can also be similar, in particular deviating by an amount of ± 10°.

[0023] In a further development of the invention, several layers of fabric are provided in the puncture protection belt, wherein the warp threads of at least two layers of the fabric of the puncture protection belt cross each other, wherein the layers of the fabric of the puncture protection belt with intersecting warp threads lie directly on top of each other or are separated by only one further layer of fabric.

[0024] For example, the puncture protection belt can be made from several layers of corduroy fabric. According to the invention, the puncture protection belt can also be made from a cross-woven fabric in which the same number and spacing of warp and weft threads are provided.

[0025] In a further development of the invention, the warp threads of layers of the puncture protection belt with intersecting warp threads have an angle of the same magnitude but different sign at the intersection with the central plane of the tire to the central plane of the tire.

[0026] Angles that differ from each other by a maximum of 10° in magnitude are considered to be of the same magnitude within the meaning of the invention.

[0027] In a further development of the invention, in the first layer of the puncture protection belt, the warp threads at the intersection with the central plane of the tire have an angle between 70° and 80°, in particular 75°, to the central plane of the tire, and in a second layer of the puncture protection belt, which lies directly on the first layer or which is separated from the first layer by only one further layer of fabric, the warp threads at the intersection with the central plane of the tire have an angle between -70° and -80°, in particular -75°, to the central plane of the tire.

[0028] In a further development of the invention, in a third layer of the puncture protection belt, which lies directly on the second layer, the warp threads at the intersection with the central plane of the tire have an angle between 70° and 80°, in particular 75°, to the central plane of the tire.

[0029] In other words, in each layer of the puncture protection belt's fabric, the sign of the angle changes, but not the magnitude of the angle.

[0030] In a further development of the invention, at least one layer of the carcass fabric extends from a first tire bead to a second tire bead and is folded around both tire beads by 180°.

[0031] In a further development of the invention, the longitudinal edges of at least one layer of the carcass fabric overlap in the area of ​​the tire's center plane. Such a tire carcass construction is also known as a French Former.

[0032] In a further development of the invention, at least one layer of the carcass fabric has a width that corresponds to approximately three times the distance between the two tire beads, so that three layers of the carcass fabric are arranged one above the other between the two tire beads.

[0033] In a further development of the invention, the longitudinal edges of at least one layer of the carcass fabric do not overlap and are arranged at a distance from each other.

[0034] The distance between the longitudinal edges, which consequently lie opposite each other, can be very small. The distance between the longitudinal edges can also be approximately half the distance between the tire beads.

[0035] In a further development of the invention, the tire carcass has a layer that extends from a first tire bead to a second tire bead and whose longitudinal edges are not wrapped around the tire bead.

[0036] Such a so-called cover layer can be part of the construction of a tire carcass for the bicycle tire according to the invention.

[0037] In a further development of the invention, it is provided that a puncture protection belt made of at least one first layer of elastic material, in particular rubber, is arranged below the tread.

[0038] A puncture protection belt made of elastic material, particularly rubber, is also extremely effective against penetrating foreign objects and results in particularly good handling characteristics in combination with the tire construction according to the invention. The puncture protection belt can consist of one or more layers of a rubber compound with a high natural rubber content. For example, a large proportion of recycled natural rubber can also be used. A high rebound elasticity or a low loss factor of the rubber compound is advantageous for low rolling resistance, so that only minimal energy losses occur when the puncture protection belt is compressed and then expanded again, a process known as flexing. In a further development of the invention, the puncture protection belt is arranged between the tread and the tire carcass, and the first layer of elastic material rests on the tire carcass.

[0039] In a further development of the invention, the puncture protection belt is arranged between two layers of fabric in the tire carcass.

[0040] In a further development of the invention, the puncture protection belt has several layers of elastic material, wherein at least two of the layers of elastic material are arranged between different fabric layers of the tire carcass.

[0041] In a further development of the invention, the thickness of the puncture protection belt gradually decreases from the central plane of the bicycle tire towards the tire beads.

[0042] Further features and advantages of the invention will become apparent from the claims and the following description of preferred embodiments of the invention in conjunction with the drawings. Individual features of the different embodiments illustrated and / or described can be combined with one another within the scope of the invention without exceeding its scope. This also applies to the combination of individual features without further individual features with which they are illustrated and / or described. In particular, this applies within the scope of the present invention to the combination of different tire carcass designs.

[0043] The drawings show:

[0044] Fig. 1 shows a schematic, partially cutaway view of a bicycle tire according to a first embodiment of the invention, from a slant above.

[0045] Fig. 2 is a schematic top view of the bicycle tire of Fig. 1,

[0046] Fig. 3 shows another schematic top view of the bicycle tire of Fig. 1, showing a first layer of the tire carcass, the sidewall reinforcement or the puncture protection belt respectively.

[0047] Fig. 4 shows a further schematic top view of the bicycle tire of Fig. 1, showing a second layer of the tire carcass, the sidewall reinforcement or the puncture protection belt, respectively; Fig. 5 shows a schematic representation of the construction of a tire carcass according to an embodiment of the invention.

[0048] Fig. 6 shows a schematic representation of the tire carcass according to a further embodiment of the invention,

[0049] Fig. 7 shows a schematic representation of the construction of a tire carcass according to a further embodiment of the invention,

[0050] Fig. 8 shows a schematic representation of the construction of a tire carcass according to a further embodiment of the invention,

[0051] Fig. 9 shows a schematic representation of the construction of a tire carcass according to a further embodiment of the invention,

[0052] Fig. 10 shows a section-by-section schematic representation of the construction of a bicycle tire according to a further embodiment of the invention and

[0053] Fig. 11 shows a sectional view of a bicycle tire according to a further embodiment of the invention.

[0054] Fig. 1 shows a schematic and partially cutaway view from an oblique top of a bicycle tire 10 according to a first embodiment according to the invention.

[0055] The bicycle tire 10 has a tire carcass 12 and a tread 14 designed for contact with the road surface. In the illustrated embodiment, the tread 14 is provided with a profile. However, a profile in the tread is not a necessary requirement within the scope of the invention.

[0056] The bicycle tire is designed for a bicycle rim (not shown) and can be used with or without an inner tube, depending on the type of rim used.

[0057] The tire carcass 12 defines a tire interior 16 in sections. The tire carcass 12 extends from a first tire bead 18 to a second tire bead 20. A bead insert 22 or 24 is provided at both the first tire bead 18 and the second tire bead 20, respectively. The bead inserts 22 and 24 can consist of plastic filaments or steel wires. Plastic filaments can be used individually or as a strand of several filaments or threads.

[0058] The tire carcass is provided with a first sidewall 26 and a second sidewall 28. The first sidewall 26 connects the first tire bead 18 to the tread 14, and the second sidewall 28 connects the second tire bead 20 to the tread 14. In Fig. 1, a boundary of the tread 14 is schematically indicated by a dashed line 30. In the illustrated embodiment, the dashed line 30 marks the transition from the tread 14 with its tread pattern to the sidewall 26, which has no tread pattern. However, markings, reflective strips, or other textures may be provided in the area of ​​the sidewall 26.

[0059] The tire carcass 12 is provided with a sidewall reinforcement 32 in the area of ​​the two sidewalls 26, 28, whereby in the illustration of Fig. 1 only the sidewall reinforcement 32 of the sidewall 26 can be seen.

[0060] In the illustrated embodiment, a puncture protection belt 36 is provided between a carcass fabric 34 of the tire carcass 12 and the tread 14. The puncture protection belt 36 can consist of one or more layers of fabric.

[0061] The side wall reinforcement 32 can also consist of one or more layers of fabric.

[0062] In the schematic representation of Fig. 1, several carcass threads 38 are indicated on the carcass fabric. These threads run parallel to each other and, as can be seen in Fig. 1, have a relatively large angle to a tire center plane. This will be explained in detail with reference to Figs. 2 to 4. The carcass fabric 34 can, for example, consist of a cord fabric. The carcass threads 38 are also referred to as warp threads of the carcass fabric. In the case of a cord fabric, the carcass threads are held together by only a few warp threads, which are arranged at a relatively large distance from each other.

[0063] The sidewall reinforcement 32 and the puncture protection belt 36 also consist of one or more layers of fabric. In Fig. 1, the warp threads of the respective fabrics are schematically indicated by thin lines in the area of ​​the sidewall reinforcement 32 and in the area of ​​the puncture protection belt 36, respectively. Fig. 2 shows a top view of the partially cutaway view of the bicycle tire 10 from Fig. 1. A tire center plane 40 is shown in Fig. 2. The angle that the carcass threads 38 make at the intersection with the tire center plane 40 is also called the carcass zenith angle. The angles of the warp threads of the fabric of the puncture protection belt 36 and of the sidewall reinforcements 32 are also given relative to the tire center plane 40.In the case of the sidewall reinforcements 32, to specify this angle, the sidewall reinforcements 32 must be mentally extended to the tire center plane 40 in order to be able to specify the angle of the warp threads to the tire center plane 40.

[0064] Figures 3 and 4 show the angles of the warp threads of the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32 relative to the tire's center plane 40. It should be noted that Figure 3 schematically shows a first layer of the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32, respectively. Figure 4 then shows a second layer of the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32, respectively, relative to the tire's center plane 40. The second layers shown in Figure 4 lie directly on top of the first layers shown in Figure 3. In other words, the second layer of the sidewall reinforcement 32 shown in Figure 4 lies on top of the first layer of the sidewall reinforcement 32 shown in Figure 3. The second layer of the puncture protection belt 36 shown in Fig. 4 rests on the first layer of the puncture protection belt 36 shown in Fig. 3.The second layer of the tire carcass 34 shown in Fig. 4 lies on top of the first layer of the tire carcass 34 shown in Fig. 3.

[0065] As can be seen in Fig. 3, the carcass threads 38 of the carcass fabric 34 form an angle X with the tire's central plane 40. In the illustrated embodiment, this angle X is +75° and, within the scope of the invention, can lie between 55° and 85°, in particular between 70° and 80°, and especially be 75°.

[0066] The angle of the warp threads of the puncture protection belt 36 to the tire's center plane 40 is denoted by Y in Fig. 3 and is -75° in the illustrated embodiment. The angle of the warp threads of the sidewall reinforcements 32 to the tire's center plane 40 is denoted by Z in Fig. 3 and is -45° in the illustrated embodiment. As explained, the representation in Fig. 3 is schematic, and to clarify angle Z, a line parallel to the tire's center plane 40 has been drawn in both the sidewall reinforcement 32 shown on the left and the sidewall reinforcement 32 shown on the right in Fig. 3. Within the scope of the invention, it is advantageous if the magnitude of the angle of the warp threads of the tire carcass 34 and the magnitude of the angle of the warp threads of the puncture protection belt 36 are equal.As already explained, the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32 each consist of two or more layers of a fabric. Figure 3 shows the angles of the warp threads of the first layer of each respective fabric.

[0067] Fig. 4 shows a representation of the bicycle tire 10 according to the invention, comparable to Fig. 3, wherein in Fig. 4 the angles of the warp threads of the respective second layer of the fabric of the carcass fabric 34, the puncture protection belt 36 and the sidewall reinforcements 32 are shown. The respective second layer of fabric shown in Fig. 4 lies directly on the respective first layer of fabric shown in Fig. 3.

[0068] It is immediately apparent that the angles of the warp threads of the superimposed layers of the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32 intersect. It is further apparent that the angles of the superimposed layers of the carcass fabric 34, the puncture protection belt 36, and the sidewall reinforcements 32 have the same absolute value but different signs.

[0069] According to Fig. 4, the carcass threads 38 or warp threads of the carcass fabric 34 in the second layer have an angle -X to the tire center plane 40. The warp threads of the second layer of the puncture protection belt 36 have an angle -Y to the tire center plane 40. The warp threads of the second layer of the sidewall reinforcements 32 have an angle -Z to the tire center plane 40.

[0070] As a result, the warp threads of directly adjacent layers of the carcass fabric 34, the puncture protection belt 36 and the sidewall reinforcements 32 intersect.

[0071] As explained above, the angle X formed by the carcass threads 38 at the intersection with the tire's central plane 40 lies, according to the invention, in a range between 55° and 85°, in particular between 70° and 80°. In the illustrated embodiment, the angle X is 70°.

[0072] In the area of ​​the sidewall reinforcements 32, the angle of the warp threads is, for example, between 40° and 50°, and particularly at 45°, as shown in Figs. 3 and 4. As will be explained further with reference to Fig. 10, the sidewall reinforcements 32 each consist of several layers of fabric, with the lowest layer of fabric extending further towards the tread 14 than the layers arranged above it, resulting in a stepped decrease in the material thickness of the sidewall reinforcements 32 from the tire bead 18, 20 towards the tread 14.

[0073] By means of the sidewall reinforcements 32, the sidewalls 26, 28 of the bicycle tire 10 according to the invention can be reinforced with a small increase in weight, so that the bicycle tire 10 according to the invention can be ridden without problems and yet the slight deformability of the tire carcass 12 in the area of ​​the tread 14 is retained.

[0074] Within the scope of the invention, the angle of the warp threads of the multiple layers of fabric in the area of ​​the puncture protection belt 36 can be between 55° and 85°, in particular between 70° and 80°, and especially at 75°, relative to the tire's central plane 40. Within the scope of the invention, it has proven advantageous if the angle of the warp threads of the layers of fabric of the puncture protection belt 36 is in the range of the angle of the carcass threads 38 of the carcass fabric 34 relative to the tire's central plane 40. In such a case, the puncture protection belt 36 leads to a significant improvement in puncture protection, while, on the other hand, it does not stiffen the tire carcass 12 in the area of ​​the tread 14 to such an extent that the slight deformability of the tire carcass 12 in the area of ​​the tread 14 would be lost. The slight deformability of the tire carcass 12 in the area of ​​the tread 14 ensures extremely advantageous driving characteristics of the tire according to the invention.The tire according to the invention enables a significantly more comfortable ride, as the tire's suspension travel is utilized more effectively. Furthermore, the tire according to the invention better hugs obstacles, resulting in improved ground contact, which leads to significantly increased traction, especially in off-road applications.

[0075] Fig. 5 shows a schematic representation of a tire carcass construction 12 according to a first embodiment. The carcass fabric 34 extends between the two bead layers 22, 24 and is folded over each bead layer by 180°. This tire carcass construction 12, shown in Fig. 5, is also known as a French Former. It can be seen that the folded sections of the carcass fabric 34 overlap between the longitudinal edges 42, 44. This overlap occurs in the area of ​​the tire center plane 40 and is only a fraction of the distance between the two bead layers 22, 24. In the area surrounding the tire center plane 40, the tire carcass 12 is thus composed of three layers of fabric, while on either side of this three-layer area it consists of only two layers of fabric.

[0076] Fig. 6 shows another construction of a tire carcass 12, also known as a French Former Bead-to-Bead. The carcass fabric 34 is again folded 180° around the two bead layers 22, 24, but the folded portion extends essentially over the entire width between the two bead layers 22, 24. Thus, between the two bead layers 22, 24, the tire carcass 12 is constructed of three layers of fabric at every point.

[0077] Fig. 7 shows another construction of a tire carcass 12. The carcass fabric 34 is again folded over each of the bead inserts 22, 24 by 180°, but the folded portion ends well before the tire center plane 40. This construction is also referred to as a turn-up. The distance between the longitudinal edges 42, 44 of the carcass fabric 34 is comparatively large and is approximately half the distance between the two tire beads or bead inserts 22, 24.

[0078] Fig. 8 shows another construction of a tire carcass 12. The carcass fabric 34 is again folded over the bead inserts 22, 24 by 180° each, with the longitudinal edges 42, 44 arranged at a small distance from the tire center plane 40. This construction is also referred to as a wide turn-up.

[0079] Fig. 9 shows a design feature for a tire carcass in which a fabric cover layer 46 extends between the bead plies 22, 24, but is not folded over the bead plies 22, 24. Such a cover layer 46 can be combined with any of the tire carcass 12 designs shown in Figs. 5 to 8. The cover layer 46 can also be incorporated between other layers, for example, the tire carcass 34.

[0080] Fig. 10 shows a schematic, section-by-section representation of the construction of a bicycle tire 10 according to the invention, compare Fig. 1. The tire carcass 12 has two layers of carcass fabric 34, with only the bead insert 24 being shown in Fig. 10, around which the carcass fabric is folded by 180°. Fig. 10 shows by way of example the construction of the tire carcass 12 according to Fig. 6. Consequently, in the area of ​​the tread 14 or in the area of ​​the tire center plane 40, there are three layers of carcass fabric 34 on top of each other. The puncture protection belt 36, which is formed from three layers of fabric, is arranged on the tire carcass 12. As explained, the warp threads of directly adjacent layers of fabric of the puncture protection belt 36 and the tire carcass 12 intersect, with the angles of the warp threads of the individual layers of fabric of the tire carcass 12 and the puncture protection belt 36 being equal or approximately equal.In the context of the invention, "approximately equal" means that the angles of the warp threads of the tire carcass 12 and the puncture protection belt 36 differ from each other by a maximum of ± 15°, in particular ± 10°. In the area of ​​the sidewall 28 shown in Fig. 10, it can be seen that three layers of the carcass fabric are also stacked on top of each other. The sidewall reinforcement 32 consists of three layers of fabric. It can be seen that the bottom layer of fabric of the sidewall reinforcement 32, which lies directly on the tire carcass 12, has the greatest extent in the direction from the tire bead with the bead insert 24 to the tread 14 of the bicycle tire. The second layer arranged on top of the bottom layer is then shorter than the bottom layer. The third layer, the uppermost layer in Fig. 10, is again shorter than the middle layer. As shown in Fig.As can be seen from 10, this results in a step-like decrease in the material thickness and thus in the stiffness of the sidewall reinforcement 32 from the tire bead with the bead reinforcement 24 towards the tread 14.

[0081] According to the invention, the sidewall reinforcement 32 should cover only between one-quarter and three-quarters, in particular two-thirds, of the surface of the respective sidewall 26, 28. The angle of the warp threads of the layers of fabric of the sidewall reinforcement 32 should differ significantly from the angle of the warp threads or carcass threads of the tire carcass 12, so that a strong stiffening of the tire carcass 12 is achieved in the area of ​​the sidewalls 26, 28.

[0082] Figure 11 shows a sectional view of a bicycle tire 100 according to a further embodiment of the invention. The bicycle tire 100 is mounted on a rim 102 and is essentially constructed the same way as the bicycle tire 10 of Fig. 1, so that only the differences from the bicycle tire 10 of Fig. 1 are explained.

[0083] Specifically, instead of the puncture protection strip 36 of the bicycle tire 10, which consists of one or more layers of fabric, the bicycle tire 100 of Fig. 11 is provided with a puncture protection belt 136, which consists of one or more layers of an elastic material, in particular rubber. As can be seen in Fig. 11, the puncture protection belt 136 has a crescent-shaped cross-section and tapers from the central plane 40 of the tire towards the tire beads 18, 20. The puncture protection belt 136 has its greatest thickness in the region of the central plane and in the area immediately adjacent to the central plane. This region of greatest thickness of the puncture protection strip 136 is thus located below the center of the tread, 14, which is in contact with a road surface when traveling straight ahead.

[0084] The puncture protection belt 136 can, as shown in Figure 11, consist of only a single layer of an elastic material. The puncture protection belt 136 rests on the tire carcass 26 and is arranged between the tread 14 and the tire carcass 12. The puncture protection belt 136 can also consist of several layers of elastic material, in particular rubber. The individual layers of the puncture protection belt 136 can also be arranged such that a fabric layer of the tire carcass 12 is positioned between individual layers of the puncture protection belt.

[0085] To achieve low rolling resistance, the puncture protection belt 136 is made from a rubber compound with a high proportion of natural rubber. Natural rubber exhibits high rebound elasticity and, consequently, a low loss factor. In other words, when the bicycle tire flexes—that is, when the puncture protection belt 136 is compressed and subsequently expanded again—very little mechanical energy is converted into heat. The high natural rubber content can also consist of recycled natural rubber.

[0086] It has been found that the puncture protection belt 136, made of one or more layers of elastic material, harmonizes particularly well with the tire construction according to the invention and results in very good driving characteristics with low rolling resistance and very good puncture protection.

Claims

Patent claims 1. Bicycle tire with a tire carcass and a tread provided for road contact, wherein the tire carcass defines at least a section of a tire interior and has two sidewalls and a tire bead in the area of ​​the respective free end of the sidewalls, characterized in that the carcass threads, in particular the warp threads, of a carcass fabric of the tire carcass at the intersection with a median plane of the tire assume an angle between 55 degrees and 85 degrees or an angle between -55 degrees and -85 degrees to the median plane and that at least one sidewall reinforcement is arranged on the tire carcass in the area of ​​the sidewalls.

2. Bicycle tire according to claim 1, characterized in that the carcass threads, in particular the warp threads, of the carcass fabric of the tire carcass assume an angle of 70 degrees to 80 degrees, in particular 75 degrees, or -70 degrees to -80 degrees, in particular -75 degrees, at the intersection with the central plane of the tire.

3. Bicycle tire according to claim 1 or 2, characterized in that the tire carcass has several layers of fabric at the intersection with the central plane of the tire, wherein the warp threads of at least two layers of fabric of the tire carcass cross each other, wherein the layers of fabric of the tire carcass with intersecting warp threads lie directly on top of each other or are separated by only one further layer of fabric.

4. Bicycle tire according to one of the preceding claims, characterized in that the sidewall reinforcement covers between 4 / 4, in particular 2 / 3, of the surface of the respective sidewall.

5. Bicycle tire according to at least one of the preceding claims, characterized in that the sidewall reinforcement has at least one layer and a maximum of four layers, in particular two or three layers, of rubberized fabric.

6. Bicycle tire according to claim 5, characterized in that the sidewall reinforcement has two or three layers of rubberized fabric, wherein the warp threads have an angle between 40° and 50° or between -40° and -50°, in particular of +45° or -45°, and the warp threads of the layers, especially the warp threads of directly adjacent layers cross, particularly at an angle of 90 degrees.

7. Bicycle tire according to one of the preceding claims, characterized in that the sidewall reinforcement has at least one layer, in particular two or three layers, of a rubber layer.

8. Bicycle tire according to one of the preceding claims, characterized in that the sidewall reinforcement has several layers of fabric and / or rubber, wherein the lowest or innermost layer of the sidewall reinforcement has the greatest extent in the direction from the tire bead to the tread of the bicycle tire, and wherein the further layers arranged on the lowest layer are each shorter than the layer below, so that a, in particular step-like, decrease in the material thickness of the tire from the tire bead to the tread results.

9. Bicycle tire according to one of the preceding claims, characterized in that a puncture protection belt made of at least one first layer of fabric is arranged between the tire carcass and the tread, wherein the first layer rests directly on the tire carcass and wherein the warp threads of the fabric of the puncture protection belt form an angle between 55 degrees and 85 degrees, in particular between 70 degrees and 80 degrees, in particular 75 degrees, or between -55 degrees and -85 degrees, in particular between -70 degrees and -80 degrees, in particular -75 degrees, at the intersection with the central plane of the tire. 0.A bicycle tire according to claim 9, characterized in that several layers of fabric are provided in the puncture protection belt, wherein the warp threads of at least two layers of the fabric of the puncture protection belt intersect, wherein the layers of the fabric of the puncture protection belt with intersecting warp threads lie directly on top of each other or are separated by only one further layer of fabric. A bicycle tire according to claim 10, characterized in that the warp threads of layers of the puncture protection belt with intersecting warp threads have an angle of equal magnitude but opposite sign at the intersection with the central plane of the tire to the central plane of the tire.

12. Bicycle tire according to claim 9, 10 or 11, characterized in that in the first layer of the puncture protection belt the warp threads at the intersection with the central plane of the tire have an angle between 70 degrees and 80 degrees, in particular 75 degrees, to the central plane of the tire, and that in a second layer of the puncture protection belt, which lies directly on the first layer or which is separated from the first layer by only one further layer of fabric, the warp threads at the intersection with the central plane of the tire have an angle between -70 degrees and -80 degrees, in particular -75 degrees.

13. Bicycle tire according to claim 12, characterized in that in a third layer of the puncture protection belt, which lies directly on the second layer or which is separated from the second layer by only one further layer of fabric, the cord threads or warp threads at the intersection with the central plane of the tire have an angle between 70 degrees and 80 degrees, in particular 75 degrees, to the central plane of the tire.

14. Bicycle tire according to at least one of the preceding claims, characterized in that at least one layer of the carcass fabric extends from a first tire bead to a second tire bead and is folded around both tire beads by 180 degrees.

15. Bicycle tire according to claim 14, characterized in that the longitudinal edges overlap at least one layer of the carcass fabric in the area of ​​the tire's central plane.

16. Bicycle tire according to claim 14, characterized in that at least one layer of the carcass fabric has a width that corresponds approximately to three times the distance between the two tire beads, so that three layers of the carcass fabric are arranged one above the other between the two tire beads.

17. Bicycle tire according to claim 14, characterized in that the longitudinal edges of at least one layer of the carcass fabric do not overlap and are arranged at a distance from each other.

18. Bicycle tire according to one of claims 14 to 17, characterized in that the tire carcass has a layer which extends from a first tire bead to a second tire bead and whose longitudinal edges are not folded around the tire bead.

19. Bicycle tire according to one of the preceding claims, characterized in that a puncture protection belt made of at least one first layer of elastic material, in particular rubber, is arranged below the tread.

20. Bicycle tire according to claim 19, characterized in that the puncture protection belt is arranged between the tread and the tire carcass and the first layer of elastic material rests on the tire carcass.

21. Bicycle tire according to claim 19, characterized in that the puncture protection belt is arranged between two layers of fabric of the tire carcass.

22. Bicycle tire according to claim 19, characterized in that the puncture protection belt has several layers of elastic material, wherein at least two of the layers of elastic material are arranged between different fabric layers of the tire carcass.

23. Bicycle tire according to at least one of claims 19 to 22, characterized in that the thickness of the puncture protection belt gradually decreases from the central plane of the bicycle tire towards the tire beads.

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