Patent Publication Number: US-9414640-B2

Title: Cycling shoe

Description:
FIELD OF THE INVENTION 
     The invention relates to a cycling shoe, and in particular, a cycling shoe having a pivoting heel portion. 
     BACKGROUND 
     Triathlons are races that consist of three different segments, or legs: swimming, cycling and running. The length of a race leg can vary depending on a particular triathlon, for example, from relatively short and easily performed (e.g., novice events) to long and grueling distances (e.g., an Ironman™ triathlon event). In all triathlons, transition areas are positioned between consecutive legs of the race and are used to store racing equipment, such as bicycles, helmets, shoes, water and other apparel and gear needed for a next leg of the race. Racers also can use a transition area to discard gear used in a just completed leg, but not needed in a following leg (e.g., discarding a wet suit after completing a swimming leg before beginning a cycling leg). 
     To reduce an overall time for completing a race, triathletes attempt to reduce the amount of time spent in a transition area. A first transition time (T 1 ), which is time elapsed while in a transition area between the swim and bike segments, can be used to remove a wetsuit, strap on a helmet, slip on a pair of cycling shoes, and mount a bicycle. A second transition time (T 2 ) is the time spent in the transition area between the bike leg and run leg of the race, and can be used to park the bicycle, remove the helmet and cycling shoes, and put on running shoes. 
     Hence, critical time is spent donning and removing cycling shoes in the T 1  and T 2  transition times. Conventional cycling/triathlon shoes have a very wide top entry with minimal Velcro or plastic straps as means of securing the foot in the shoe. The heel portion of the shoe is immobilized to accomplish maximum firmness and power transfer. These cycling shoes can include a loop attached to, or integrated with the heel to facilitate inserting the cyclist&#39;s foot into the shoe by pulling the loop backward and upward while the foot is inserted into the top entry. 
     SUMMARY 
     Embodiments consistent with the claimed inventions relate to a cycling shoe that has a movable heel, which can selectively be placed into one of two available stable states, or bistable states. In one state, the heel is in an open position and allows entry and removal of a cyclist&#39;s foot through the rear of the shoe. In the closed state, the cycling shoe can be secured to a cyclist&#39;s foot because the heel includes connecting elements that can be held in tension with the upper using one or more tensioning devices connected to the upper. Bistability is provided because the heel forms a curved surface with attachment to a heel section of the sole. While the heel remains bendable, it must overcome an energy barrier with movement between open and closed states. Thus, the heel can readily be placed into one bistable state and remain that state until moved again to the other bistable state. 
     More specifically, a cycling shoe consistent with the claimed invention includes a sole having a toe section, a ball section, an arch section, and a heel section. An upper is connected to the sole to form a cavity for receiving a foot of a cyclist and includes first and second peripheral edge portions. A heel including a first lateral side, a second lateral side, a lower heel portion is connected to the heel section of the sole and an upper heel portion pivotable to selectively rotate the heel into bistable open and closed positions with respect to the sole about a pivot area of the lower heel portion, where the pivot area is adjacent to where the lower heel connects to the heel section of the sole. The cycling shoe includes a fastening system having a first connecting element extending from the first lateral side of the heel, a second connecting element extending from the second lateral side of the heel, and at least one tensioning device on the upper. The at least one tensioning device cooperates with the first and second connecting elements to provide a tension relationship between the heel in the closed position and the upper with a cyclist&#39;s foot therebetween. With the heel in the closed position, the first and second peripheral edge portions respectively face the first and second lateral sides of the heel, an area between the first peripheral edge portion of the upper and the first lateral side of the heel and an area between the second peripheral edge portion of the upper and the second lateral side of the heel are substantially open. Each of the open areas extends at least substantially entirely to the sole. 
     In another embodiment consistent with the claimed invention, a cycling shoe includes a sole having an inner side and an outer side. The inner side includes a toe section, a ball section, an arch section, and a heel section. The outer side includes a mounting section including plural orifices for connecting a cleat. An upper of the cycling shoe is connected to the sole to form a cavity for receiving a foot of a cyclist. A heel of the cycling shoe includes a first lateral side, a second lateral side, a lower heel portion connected to the heel section of the sole, and an upper heel portion pivotable to selectively rotate the heel into bistable open and closed positions with respect to the sole about a pivot area of the lower heel portion. The cycling shoe includes a fastening system having a first connecting element extending from the first lateral side, a second connecting element extending from the second lateral side, and at least one tensioning device on the upper. The at least one tensioning device cooperates with the first and second connecting elements to provide a tension relationship between the heel, while in the closed position, and the upper with a cyclist&#39;s foot therebetween. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and exemplary only and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention that together with the description serve to explain the principles of the invention. In the drawings: 
         FIG. 1  is a side view diagram of a cycling shoe with a pivoting heel portion in a closed position according to an exemplary embodiment. 
         FIG. 2  is a top view diagram of the cycling shoe shown in  FIG. 1  with the pivoting heel portion in a closed position. 
         FIG. 3  is a cross-section view diagram of a cycling shoe having a pivoting heel portion in an open position according to an exemplary embodiment. 
         FIG. 4  is a rear view diagram of a cycling shoe having a pivoting heel portion in an open position according to an exemplary embodiment. 
         FIG. 5  is a side view diagram of the cycling shoe having a pivoting heel portion in a closed position according to another exemplary embodiment. 
         FIG. 6  is a perspective view diagram of a cycling shoe having a pivoting heel portion in an open position according to another exemplary embodiment. 
         FIGS. 7A to 7C  are rear view diagrams of cycling shoes, each showing an exemplary strap and a pivoting heel portion configuration. 
         FIG. 8  is a side view diagram of the cycling shoe having a pivoting heel portion in a closed position according to another exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The various aspects are described hereafter in greater detail in connection with a number of exemplary embodiments to facilitate an understanding of the invention. However, the invention should not be construed as being limited to these embodiments. Rather, these embodiments are provided so that the disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Descriptions of well-known functions and constructions are omitted for clarity and conciseness. Further, it should be emphasized that the terms “comprises” and “comprising,” when used in this specification, are taken to specify the presence of stated elements, features, integers, steps or components; but the use of these terms does not preclude the presence or addition of one or more other elements, features, integers, steps, components or groups thereof. 
     Competition and pressure for reducing time has led to the development of specialized triathlon clothing that is adequate for both swimming and cycling, meaning many racers&#39; transitions consist of little more than removing wetsuit and goggles and pulling on a helmet and cycling shoes. In some cases, racing cyclists leave shoes attached to their bicycle pedals (e.g., clipless configurations) and slip their feet into them while riding, while other racers prefer putting cycling shoes on before mounting their bicycles. In either case, the inventor has recognized that reducing the time spent at a transition area while providing ease of performing the transition can be a critical element in the outcome of a race or other event that involves rapid donning of cycling footwear. 
     With reference now to  FIGS. 1 and 2 , a cycling shoe according to an exemplary embodiment is now described.  FIGS. 1 and 2  respectively show a side and top view of a cycling shoe  10 , such as a triathlon cycling shoe, which includes a main shoe portion  15  including an upper portion (or upper)  16 , a sole  17 , and a pivotable heel  12  connected to the sole  17 . The sole  17  has upper and lower outer surfaces that include a toe section, a ball section, an arch section, and a heel section. The upper  16  covers the toe, ball and arch sections of the sole  17 . The pivotable heel  12  includes a heel portion  22  that can be pivoted about a crease area  14  along a bottom portion thereof to position the pivotable heel  12  between an open position in which a cyclist&#39;s foot  24  can be inserted into a cavity  18  formed by the upper  16  and the sole  17  attached to the upper  16 , and a closed position in which the heel portion  12  faces the cavity  18  and can be fastened to the upper  16  to secure the cycling shoe  10  to the foot  24 . 
     In the closed position, the heel portion  22  of pivotable heel  12  engages a cyclist&#39;s heel and is in a tension relationship with the upper  16  to secure the cyclist&#39;s foot in the upper  16 . The heel portion  22  is flexible and can be a molded structure. For example, the heel portion can be made of natural materials such as leather, polymeric woven materials, plastic, rubber, synthetic rubber or combinations thereof, and can be formed using the same material as the upper  16  of the main shoe portion  15 , although the upper  16  and heel portion can be formed of different materials. 
     The cycling shoe  10  includes a fastening mechanism  26  for removably attaching the pivotable heel portion  12  to the upper  16  and providing the tension relationship between strap retaining portion  33  of the pivotable heel  12  and the main shoe portion  15  in a position that secures the cycling shoe  10  to the cyclist&#39;s foot  24 . In the exemplary embodiment shown in  FIGS. 1 and 2 , the fastening mechanism  26  includes a strap  28  provided on each side of the cycling shoe  10 . Each strap  28  can be a ratchet cinch type strip having teeth, ridges or notches  30  that are provided along at least one side thereof and is designed to cooperate with a tensioning device  32 , such as a ratcheting buckle device, although in some embodiments a fastening mechanism  26  can include straps that cooperate with a tensioning device  32  that do not include teeth, ridges or notches. 
     Each strap  28  can be attached to a strap retaining portion  33  that can be positioned at the back of the heel portion  22 . The strap retaining portion can be attached to the heel portion using adhesive, stitching (thread), staples and/or rivets etc., or can be integrated with the heel portion  22 . In other embodiments, a strap  28  can be a continuous strip threaded through the strap retaining portion  33  or across or though the heel portion  22 , with ends of the continuous strip extending from each side of the strap retaining portion  33 . With a continuous strip as the strap  28 , a retaining element can be included, such as a rivet, stitching, adhesive, staple, one or more member extending from the continuous strip that engages a part of the strap retaining portion  33  or heel portion  22 , or another retaining mechanism that can prevent the strap from being pulled off of the cycling shoe  10  with only one strap being pulled forward at a time. 
     To operate the fastening mechanism  26 , after the cyclist&#39;s foot  24  is inserted into the cavity  18  provided by the upper  16  and the sole  17 , or while inserting foot  24  into the cavity  18 , the cyclist can grab a strap  28  on each side of the cycling shoe  10  and thread the ends of the straps  28  through each respective tensioning device  32 . Next, the cyclist can pull each threaded end of a strap  28  further through the tensioning device  32  toward the toe cap in the longitudinal direction of the shoe and in a slightly downward direction until the pivotable heel  12  contacts the cyclist&#39;s heel. The ends of the strap  28  can be pulled through the tensioning device  32  to an extent in which the fit around the cyclist&#39;s heel is at least as snug, has a same firmness as would exist with a conventional top entry shoe, or to a desired tension amount that increases with increasing combined distances of the straps  28  pulled through the tensioning devices  32 . 
     In some embodiments, as shown in  FIG. 1 , a central axis  38  of each strap  28  can be provided an angle φ to a horizontal line  40  that generally follows the bottom of the shoe  10  and passes through the lowermost parts of the sole  17  at the flex point at the ball of the foot and at the heel. In this way, the strap retaining portion  33  of the pivotable heel  12  tightens the heel portion  22  onto the heel of the cyclist&#39;s foot  24  near where the upper side of the cyclist&#39;s calcaneus bone and Achilles tendon meet to ensure a “lock” of the cycling shoe  10  on the cyclist&#39;s foot  24 . To provide comfort and to further prevent movement of the foot  24  in the cycling shoe  10 , the interior of cycling shoe  10  can be provided with linings or padding (not shown), although the shoe upper  16 , inner portion of the sole  17 , and/or the heel portion  22  can include little or no linings and/or padding. 
     The cycling shoe  10  can generally function as a conventional cycling shoe, but is different from conventional cycling and triathlon bike shoes in that a pivotable heel  12  of the cycling shoe  10  can pivot relative the sole  17  at the crease area  14  to fold back and away from the interior cavity  18  of a main shoe portion  15  to allow rear entry of a cyclist&#39;s foot  24  into the cycling shoe  10 . In a preferable embodiment, the cycling shoe  10  is configured for use in a known clipless, or cleat-and-pedal system, and can be mounted in the open position on a pedal of a cycle using such a system. In a clipless system, a cleat (not shown) is usually attached to the sole  17 , via the mounting orifices, at a location under the ball of the cyclist&#39;s foot  24 . Each pedal of the cyclist&#39;s bicycle includes a binding mechanism that receives the cleat mounted on the cycling shoe  10  to “lock in” the cleat and allow the cyclist to push or pull in virtually any direction during a cycle stroke. While the cross-section in  FIG. 3  shows only one mounting orifice  50 , it is to be understood that plural mounting orifices can be provided and that the location and number of mounting orifices is would be determined on which cleat-and-pedal system is utilized. In an embodiment, sole  17  can have an inner side and an outer side, where the inner side includes a toe section, a ball section, an arch section, and a heel section, and the outer side includes a mounting section having the plural orifices  50  (only one shown in  FIG. 3 ) for connecting a cleat. 
     Additionally, the pivotable heel  12  can maintain its position in either an open or closed state. As shown in  FIG. 2 , the cross-section diagram of  FIG. 3 , and the rear view diagram of  FIG. 4 , the heel portion  22  is attached to a curved rear heel end of the sole  17  by stitching, adhesive, rivets, and/or staples, combinations thereof, or any known means of attaching heel elements to a sole of a shoe. In the exemplary embodiment shown in  FIGS. 3 and 4 , the heel portion  22  is shown attached to the sole  17  using stitching  42 . Also shown in  FIG. 4  is stitching  44   a  and  44   b , which can be provided to shape the heel portion  22 , although it is to be understood that the shape of the heel can be provided in other ways in other embodiments. 
     The combination of the curved shape of the heel of the sole  17  and attached heel portion  22  can provide bistable positioning as follows: in the upright, open position, the material of the heel portion following the curved heel portion of the sole  17  provides one state of minimal free energy, and when the heel portion  22  moved in a rotational direction A away from the toe  36  of shoe, the heel portion  22  overcomes a barrier and can make a transition from the closed state of minimal free energy to an open state of minimal free energy. In some embodiments, in the open state a dimple  46  can form in a center portion of the heel portion  22  after overcoming the barrier between the open and closed states to transform the interior surface of the heel portion  22  facing the upper  16  from a concave shape as shown in  FIGS. 1 and 2  to the convex shape shown in  FIG. 3 . Thus, the heel portion  22  can be easily flipped by cyclist to rotate the heel portion  22  generally about 45 to 90 degrees in either direction to orient the pivotable heel  12  between the bistable open and closed positions. These stable states allow the cycling shoe to be attached to a bicycle pedal in the open state prior to the cyclist approaching the bicycle. For example, a bicycle having a cycling shoe  10  attached to each of its pedals can be provided at a transition area prior to the cyclist arriving at that transition area and the cyclist can insert her foot into the cavity  18  without any substantial interference from the heel portion  22  and begin to pedal the bike immediately thereafter. Alternatively, the shoe can be provided elsewhere in the transition area and the cyclist can quickly insert each of her feet into one of the waiting cycling shoes  10 . 
     After the cyclist&#39;s foot is inserted into the main shoe portion  15 , the heel portion  22  can moved in a rotational direction opposite to direction A so the heel portion  22  is pivoted relative to the sole  17  at the crease area  14  into the closed state where the heel portion is adjacent to the back of the heel of the cyclist&#39;s foot. The dimple  46  is removed as the heel portion transitions into the closed state. Thereafter, the cyclist can thread the straps  28  through the to provide a snug fit against the cyclist&#39;s heel to thereby secure the cyclist&#39;s foot  24  in the cycling shoe  10 . In another embodiment, the length of each strap  28  can be sufficiently long and flexible to allow the straps  28  to remain in a respective tensioning device  32  while the pivotable heel  12  is in the open state. Further, some embodiments can include a connection between the straps  28  on each cycling shoe  10  so the rider can pull both straps  28  simultaneously. Strap ends having a connection therebetween also would prevent the strap ends from interfering with the pedaling mechanisms, such as the chain and sprockets. In any of these embodiments, the cyclist can reduce an amount of elapsed transition time while mounting a bicycle because the cyclist&#39;s foot can be inserted into the shoe and the cyclist can begin pedaling virtually immediately. Further, the straps  28  can be easily pulled as soon as the cyclist&#39;s foot is inserted into the main shoe portion  15  or at any later time while pedaling, for example, while in or after exiting a transition area. 
     The upper  16  of the main shoe portion  15  can be made of natural materials such as leather, polymeric woven materials. The upper  16  is preferably shaped to form a snug, tight or substantially tight fit of the cyclist&#39;s foot  24  with the cycling shoe secured to the foot  24 , and is not designed to be opened at the top as with conventional top entry cycling shoes. Some embodiments of the cycling shoe  10  can have tensioning mechanisms over the top of the front of the shoe  10  (not shown), but this is strictly for ensuring a snug or tight fit of the cycling shoe around the cyclist&#39;s foot and not a mechanism that allows the cyclist to take off or put on the shoe  10 . Additionally, the upper  16  can have a seamless interior to allow for efficient water drainage, and can include openings (e.g., holes) and areas or patches of mesh material or otherwise breathable material in at least one or more locations thereof. 
     The sole (or outsole)  17  of the main shoe portion  15  is preferably made low weight, high strength, stiff, or substantially rigid material, such as a carbon composite (e.g., carbon fiber, carbon/glass fiber), plastics (e.g., nylon or fiberglass reinforced nylon), rubber, or combinations thereof, to provide of sufficient stiffness index for efficient translation of power from the sole  17  of main shoe portion  12  to a surface of a bicycle pedal. In some embodiments, a stiffness index of the sole can be about 5.0 or greater to provide efficient power transfer, although some embodiments can have a sole stiffness exceeding 5.0, e.g., from 7.0 to 12.0, to provide more efficient power transfer from the cyclist&#39;s legs, to the sole  17 , and to a pedal of the bicycle. Because advances in pedal designs have resulted in smaller, lightweight pedals having a reduced usable area for contact with a shoe sole, material for sole  17  can be chosen to have a sufficiently high stiffness index to distribute forces where a small pedal area meets the sole  17 . This can provide comfort for the cyclist&#39;s foot as well as provide more efficient power transfer compared with more flexible, lower stiffness index soles. 
     For example, an embodiment using a carbon composite for high strength, stiff and light weight sole  17  can use a different material, such as rubber, leather, plastic, cloth, canvas, or another material for the heel portion. For example, an embodiment can include a high performance sole such as a carbon composite sole and also include an anti slip rubber outer surface on the lower heel portion  22  of the cycling shoe  10  to provide stability to the cyclist when the cyclist&#39;s foot is put down on the ground. In other embodiments, the lower heel portion  28  and the upper  16  of the main shoe portion  15  can be provided with breathable material, such as a mesh patches (not shown) or another breathable fabric that allows air to circulate, allowing water and sweat to evaporate. In some embodiments, an expandable mesh material or neoprene, for example, can be provided to allow stretching or expanding the shoe cavity  18  or heel portion  12 . For example,  FIGS. 2 to 4  show a mesh material  48  provided on the upper  16  at the entrance of the cavity  18 . 
     It can be readily seen from  FIGS. 1-4 , an act of tightening both ends of the strap  28  can be performed by a cyclist using each hand a respective strap end simultaneously, which can be in rapid fashion to reduce the transition time T 1 . Similarly, transition time T 2  can be reduced by rapidly removing the cyclist&#39;s foot  20  from the cycling shoe  10  during an operation of the tensioning device  32 , which releases the engaging mechanism of the tensioning device from the teeth, ridges or notches  30  of the strap  28 . For example, the cyclist can remove his or her foot  24  from the cavity  18  while manipulating a quick release buckle. 
     In a preferred embodiment, the cycling shoe  10  can include an open area  52  positioned between the pivotable heel  12  and the main shoe portion  15 , which can promote quick drainage of residual water from a swimming leg of a race and/or ventilation of the cycling shoe. Accordingly, the cycling shoe  10  can be more amenable to cycling in bare feet which can reduce a T 1  transition time because a cyclist can avoid wearing socks or drying feet before insertion into the cycling shoe  10 . Additionally, the open area  52  can reduce overall weight of the cycling shoe, and/or eliminate pinching or abrasive action that can occur if the sidewall of the pivotable heel  12  were to contact the sidewall of the upper  16  of the main shoe portion  15 . 
     The fastening mechanism that secures the pivotable heel  12  of the cycling shoe to the cyclist&#39;s foot can include a configuration other than a strip that threads through a tensioning device.  FIGS. 5 to 7C  show exemplary embodiments of a cycling shoes  110   a  and  110   b , for example triathlon cycling shoes, which use a detachably connectable hook and loop type fastener (e.g., Velcro™). The cycling shoe  110  has similar elements as shown in  FIGS. 1-4 , with slight modifications, and therefore similar reference numerals (i.e., those with 100 added to a reference number described above) will be used for the same elements. Unless described otherwise, similarly numbered items can be as described above. 
     With reference now to  FIG. 5 , a cycling shoe  110   a  includes a main shoe portion  115  including an upper  116   a , a sole  117 , and a pivotable heel  112  connected to the sole  117 . The pivotable heel  112  includes a heel portion  122   a  that can be pivoted about a crease area  114  along a bottom portion thereof to position the pivotable heel  112  between an open position in which a cyclist&#39;s foot can be inserted into a cavity  118  formed by the upper  116   a  and the sole  117  attached to the upper  116   a , and a closed position in which the heel portion  122   a  faces the cavity  118  and can be fastened to the upper  116   a  to secure the cycling shoe  110   a  to a cyclist&#39;s foot (not shown). 
     In the closed position, the heel portion  122   a  of pivotable heel  112  can engage a cyclist&#39;s heel in a tension relationship with the upper  116   a  to secure the cyclist&#39;s foot in the upper  116   a . The fastening mechanism for cycling shoe  110   a  differs from the that described above in that the tension relationship between the main shoe portion  115  and the heel portion  112  is provided by connecting the straps  128  connected to the pivotable heel  112  to the main shoe portion  115  using, on each side of the shoe  110   a , loop (or hook) surface  132  on the strap  128  and a hook (or loop) surface  134  and main shoe portion  116 . As described herein, the heel portion  112   a  of pivotable heel  112  is connected to the sole  117  such that it is bistable can be positioned into either the open or closed position. 
       FIG. 6  is a perspective diagram of a cycling shoe  110   b  according to another exemplary embodiment. The cycling shoe  110   b  is similar to the cycling shoe  110   a , except the upper  116   b  and the pivotable heel  122   b  are formed from continuous material. That is, the upper portion  116   b  and the heel portion  122   b  have connecting segments  140   a  and  140   b , which can be formed by creating an area  152  between the heel portion  122   b  and the upper  116   b.    
       FIGS. 7A to 7C  show exemplary strap configurations that can be used in any of the forgoing embodiments. In  FIG. 7A , the heel portion  122  includes openings though which a passageway  156  is formed for attaching a continuous strap  128  to the heel portion  122 . While not shown, the strap can include a retaining element, such as a molded hook or rivet, to prevent the strap  128  from sliding out of the passageway  156 .  FIG. 7B  shows an exemplary configuration in which a single continuous strip is attached to an outer surface of the heel portion  122 , for example, by using stitching  157 .  FIG. 7C  shows an exemplary embodiment in which separate strap sections  128   a  and  128   b  are connected to the heel portion  122  via stitchings  158  and  159 , respectively. 
       FIG. 8  is a side view diagram of a cycling shoe  210  according to another exemplary embodiment. The cycling shoe  210  has elements similar to those shown in  FIGS. 1-4 , with slight modifications, and therefore similar reference numerals (i.e., those with 200 added to a reference number described above with respect to  FIGS. 1-4 ) will be used for the similar elements. Unless described otherwise, similarly numbered items can be as described above. 
     With reference to  FIG. 8 , a cycling shoe  210  includes a main shoe portion  215  including an upper  216 , a sole  217 , and a pivotable heel  212  connected to the sole  117 . The pivotable heel  212  includes a heel portion  222  that can be pivoted about a crease area  214  along a bottom portion thereof to position the pivotable heel  212  between an open position in which a cyclist&#39;s foot can be inserted into a cavity  218  formed by the upper  216  and the sole  217  attached to the upper  216 , and a closed position in which the heel portion  212  faces the cavity  218  and can be fastened to the upper  116  in a tension relationship to secure the cycling shoe  210  to a cyclist&#39;s foot (not shown). 
     An opening  252  is provided between the upper  216  and the pivotable heel  212  and includes elastic mesh material  258  that can assist in retracting the pivotable heel  212  from the open position through to the closes position, although the opening can be left open or include another kind of elastic material. For the purposes of this application, with the depicted openings  252 ,  152  and  52  including a mesh or another breathable and elastic filler material, the opening is a substantially open area, although a substantially open area also includes an opening having no such filler material. Further, although the upper  216  and the heel portion  222  are shown as separate portions, these portions can include a connecting portion between them at the bottom of the opening  252 , such as described above in connection with  FIG. 6 . 
     The fastening mechanism for cycling shoe  210  differs from those described above in that the tension relationship between the main shoe portion  215  and the heel portion  212  is provided by a cord  228 , such as an elastic cord, (e.g., a rubberized “bungee” type chord), or any other elastic type of cord. The cord  228  can be threaded though one or more passageway  260  in or on the upper  216 , and one or more passageway  262  in or on the heel portion  222 . Alternatively, the cord  228  can be threaded through eyelets, loops or any other known device connected to the cycling shoe  210  that can retain the cord to the upper  215  and the pivotable heel  212 . 
     At the top side of the shoe is a tensioning device  232  through which the cord  228  is threaded. The cord  228  is sufficiently long to allow an end section thereof to protrude from the tensioning device  232  while the pivoting heel  212  is in the open bistable position and permit the cyclist to grab the end section to pull the cord through the tensioning device  232  to an extent necessary to bring the heel portion  222  into a tensioning relationship with the upper  216 . The tensioning device  232  can be connected to the upper  216  to allow for a one handed rapid tensioning operation. The tensioning device  232  can include a quick release mechanism that allows the cyclist to rapidly release the cord in the tensioning device and permit retraction of the pivotable heel  212  and withdrawal of the cyclist&#39;s foot from the cycling shoe  210 . 
     Those in the art will recognize various modifications can be made to the exemplary embodiments described herein. For example, an element capable of being manipulated into at least two states can be used in addition to a heel portion to provide open and closed orientation of a pivotable heel. Returning to  FIG. 7C , for example, an embodiment can include a bistable element  160  that can be included in or on the heel portion  122 . The bistable element  160  can be manipulated to move it into either a closed or open position. The bistable element  160  can be used in any embodiment and comprise a normally curved material that can maintain the pivotable heel  22 ,  122   a ,  122   b  and  222  in an upright stable closed position and be bent in a direction away from the toe into a second stable and open position. The heel portion  122  can include the bistable element  160 , for example, as an attachment to the strap retaining portion  33 , as a bistable state strip sewn into the heel portion  22 ,  122 ,  222 , and/or the additional element can form part of the attachment of the heel portion  22 ,  122 ,  222  to the sole  17 ,  117  and  217 . 
     Embodiments of cycling shoes consistent with the claimed invention allow for rapid entry a cyclist&#39;s foot into the cycling shoe, and rapid fastening and securing of the cycling shoe to the cyclist&#39;s foot. The claimed cycling shoe also can allow for quick unfastening and removal of the cyclist&#39;s foot from the cycling shoe. Additionally, exemplary embodiments described herein can be readily modified for use with any particular type of cleat and/or pedal system, or embodiments of the cycling shoe can include no cleats. While a “bicycle” has been described above in various embodiments, the clamed cycling shoe can be used with any type of cycling machine in which pedaling is required for operation. The claimed invention is particularly suitable for use in racing applications, such as triathlon races, where transitions from occur between cycling and at least one sport activity other than cycling (e.g., swimming or running), although the cycling shoe can be applied to other types of cycling activity where no such transition occurs. 
     Although a limited number of embodiments is described herein, one of ordinary skill in the art will readily recognize that there could be variations to any of these embodiments and those variations would be within the scope of the appended claims. Thus, it will be apparent to those skilled in the art that various changes and modifications can be made to the cycling shoe described herein without departing from the scope of the appended claims and their equivalents.