Patent Publication Number: US-6212774-B1

Title: Bearing assembly for bicycle parts

Description:
This application is a division of Ser. No. 09/108,246, filed Jul. 1, 1998, now U.S. Pat. No. 5,984,528. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention generally relates to a bearing assembly for bicycle parts. More specifically, the present invention relates to a bicycle bearing assembly, which has inner and outer members formed by rolling, instead of by machining. 
     2. Background Information 
     Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. Also, bicycle manufacturers are also constantly improving the manufacturing techniques utilized to make the various components for reducing costs. One particular component of bicycles, which have been extensively redesigned over the past years, is the bearing assemblies, which are used to form the bottom bracket and the front and rear hubs. 
     The bottom bracket has a shell fixed to the frame of the bicycle and a spindle rotatably mounted within a portion of the bicycle frame. Bearings are installed between the outer tubular member and the spindle such that the outer tubular member rotates freely about the spindle. Pedals are coupled to the ends of the spindle by a pair of cranks. An example of a prior art bottom bracket is disclosed in U.S. Pat. No. 4,150,859 to Segawa. 
     Similarly, front and rear hubs for a bicycle have a hub axle or spindle rotatably coupled within an outer tubular member or shell. In the case of a hub, the hub axle or spindle is fixedly coupled to the bicycle frame and the outer tubular member or shell is fixedly coupled to the spokes of a bicycle wheel such that the bicycle wheel rotates about the axis of the hub axle or spindle. Bearings are installed between the outer tubular member and the hub axle or spindle such that the outer tubular member rotates freely about the hub axle or spindle. 
     The outer tubular members and the spindles are typically constructed through expensive machine operations. In particular, it is important that the bearing engagement surfaces of the outer tubular member and the spindle be smooth and without imperfections so that the spindle and outer tubular member rotate smoothly relative to each other via the ball bearings or bearing members. Typically, these machining operations produce small micro-grooves, which adversely affect the relative rotational movement between the spindle and the outer tubular member. 
     In view of the above, there exists a need for an improved a bicycle bearing assembly which overcomes the problems in the prior art devices and which is relatively easy to manufacture and assembly. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide a bicycle bearing assembly, which is relatively easy to manufacture and assembly. 
     Another object of the present invention is to provide a bicycle bearing assembly, which is relatively inexpensive to manufacture. 
     Still another object of the present invention is to provide a bicycle bearing assembly, which can be manufactured without significant machining. 
     The present invention can basically be obtained by providing a bicycle bearing assembly comprising an elongated inner member, a tubular outer member and a plurality of first bearing members. The elongated inner member has a first end, a second end, and an outer surface extending therebetween, with at least a first annular groove formed in the outer surface of the elongated inner member. The tubular outer member has a first open end, a second open end, and internal and external surfaces extending between the first and second open ends of the tubular outer member. The internal surface of the tubular outer member is deformed to form a second annular groove in the internal surface of the tubular outer member and a first annular bulge in the external surface by formation of the second annular groove. The first bearing members are located between the first annular groove of the elongated inner member and the second annular groove of the tubular outer member. 
     The bicycle bearing assembly according to the present invention also preferably includes a third annular groove formed in the outer surface of the elongated inner member. The tubular outer member is further deformed to form include a fourth annular groove in the internal surface of the tubular outer member and a second annular bulge in the external surface of the tubular outer member, which is formed by the formation of the third annular groove. A plurality of second bearing members are located between the third annular groove of the elongated inner member and the fourth annular groove of the tubular outer member. 
     In accordance with another aspect of the present invention, an outer race for a bicycle bearing assembly is provided. The outer race comprising a first open end, a second open end and a tubular member. The tubular member has internal and external surfaces extending between the first and second open ends, with the internal surface deformed to form a first annular groove in the internal surface and a first annular bulge in the external surface by the formation of the first annular groove. In accordance with this aspect of the present invention the outer race preferably also includes a second annular groove formed in the internal surface of the tubular member and a second annular bulge in the external surface of the tubular member by formation of the third annular groove. 
     The foregoing objects can also be attained by providing a method of forming a bicycle bearing assembly, comprising the steps of: forming an elongated inner member having a first end, a second end and an outer surface extending therebetween; forming a first annular groove in the outer surface of the inner member; forming a tubular outer member having a first open end, a second open end and internal and external surfaces extending between the first and second open ends of the tubular outer member; deforming the internal surface of the tubular outer member by rolling to form a second annular groove in the internal surface of the tubular outer member and forming a first annular bulge in the external surface of the tubular outer member by formation of the second annular groove; and inserting a plurality of first bearing members located between the first annular groove of the elongated inner member and the second annular groove of the tubular outer member. 
     The method of forming a bicycle bearing assembly in accordance with the present invention also preferably includes the steps of forming a third annular groove in the outer surface of the elongated inner member; deforming the internal surface of the tubular outer member by rolling to form a fourth annular groove in the internal surface of the tubular outer member and a second annular bulge in the external surface of the tubular outer member by formation of the fourth annular groove; and inserting a plurality of second bearing members between the third annular groove of the elongated inner member and the fourth annular groove of the tubular outer member. 
     Other objects, advantages and salient features of the invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the attached drawings which form a part of this original disclosure: 
     FIG. 1 is a side elevational view of a bicycle with bearing assemblies installed therein in accordance with one embodiment of the present invention; 
     FIG. 2 is a partial longitudinal cross-sectional view of a bottom bracket shell of the bicycle frame and a first bearing assembly, which forms the bottom bracket of the bicycle illustrated in FIG. 1; 
     FIG. 3 is a side elevational view of the crank spindle or inner member for the first bearing assembly, which forms the bottom bracket of the bicycle illustrated in FIG. 1; 
     FIG. 4 is a partial longitudinal cross-sectional view of the outer tubular member or shell for the first bearing assembly, which forms the bottom bracket of the bicycle illustrated in FIG. 1; 
     FIG. 5 is a partial longitudinal cross-sectional view of the outer tubular member or shell for the first bearing assembly, prior to being deformed; 
     FIG. 6 is a partial schematic longitudinal cross-sectional view of a pair of dies with the crank spindle or inner member of the first bearing assembly being deformed by cold rolling; 
     FIG. 7 is a partial schematic longitudinal cross-sectional view of a pair of dies with the outer tubular member of the first bearing assembly being deformed by cold rolling; 
     FIG. 8 is a partial schematic end view of the outer tubular member for the first bearing assembly being deformed by cold rolling; and 
     FIG. 9 is a partial longitudinal cross-sectional view of a second bearing assembly, which forms the front hub of the bicycle illustrated in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to FIG. 1, a bicycle  10  is illustrated with bicycle bearing assemblies  12 ,  14  and  16  coupled thereto in accordance with the present invention. Bicycle  10  basically includes a bicycle frame  20  with front and rear wheels  22  rotatably coupled thereto and a drive train  23 . Bicycles such as bicycle  10  are well known in the art, and thus, bicycle  10  and its various components will not be discussed or illustrated in detail herein. It will be apparent to those skilled in the art that bicycle  10  can be any type of bicycle, e.g., mountain bike, a hybrid bike or a road bike. 
     Bicycle bearing assembly  12  is illustrated as a bottom bracket, which is coupled to bottom bracket shell  24  of bicycle frame  20 . Bicycle bearing assembly  12  supports a pair of cranks  26  for rotation relative to frame  20 . Bicycle bearing assembly  14  is illustrated as a front hub, which rotatably supports one of the wheels  22  to bicycle frame  20 . Bicycle bearing assembly  16  is illustrated as a rear hub or free wheel, which rotatably supports the other of the wheels  22  to bicycle frame  20 . 
     Referring now to FIG. 2, bearing assembly  12  forms the bottom bracket of bicycle  10  for rotatably coupling cranks  26  to bicycle frame  20  about a longitudinal axis O. In particular, bearing assembly  12  is coupled to the bottom bracket shell  24  of bicycle frame  20 , and cranks  26  are non-rotatably coupled to the ends of bearing assembly  12  by fixing bolts  28  (only one shown in FIG.  1 ). Bearing assembly  12  basically includes an elongated inner member or crank spindle  30 , a tubular outer member or shell  32 , two sets of bearing members  34   a  and  34   b,  a pair of retainers or cages  36   a  and  36   b,  a pair of seals  38   a  and  38   b  and a pair of adapters  40   a  and  40   b.    
     Crank spindle  30  is designed to rotate within tubular outer member  32  via bearing members  34   a  and  34   b.  Accordingly, crank spindle  30  acts as an inner race, which is fixedly coupled to cranks, while tubular outer member  32  acts as an outer race, which is fixedly coupled to the bottom bracket shell  24  of bicycle frame  20 . The bearing members  34   a  and  34   b  are preferably steel balls with each set of bearing members  34   a  and  34   b  having seven steel balls therein. Of course, it will be apparent to those skilled in the art from this disclosure that fewer or more steel balls can be utilized in each set of bearing members  34   a  and  34   b.    
     Referring now to FIG. 3, crank spindle  30  is an elongated member having a first end  46   a,  a second end  46   b,  an outer surface  48  extending between first end  44   a  and second end  46   b  and the longitudinal axis O extending therethrough. First and second ends  44   a  and  46   b,  respectively, have axially extending threaded bores  50   a  and  50   b  for threadedly receiving one of the fixing bolts  28  to fixedly secure one of the cranks  26  thereto. Outer surface  48  along the first and second ends  46   a  and  46   b  of crank spindle  30  has a non-circular cross-section for non-rotatably receiving one of the cranks  26  thereon. For example, outer surface  48  along first and second ends  46   a  and  46   b  can have a plurality of flat surfaces formed thereon. Alternatively, serrations could be formed at first and second ends  46   a  and  46   b  of crank spindle  30 . The serrations are obtained by integrally forming eight projections of an angular cross-section at circumferentially spaced positions of the first and second ends  46   a  and  46   b . Preferably, the first and second ends  46   a  and  46   b  taper outwardly towards the free ends of crank spindle  30 . In any event, the cranks  26  have mating internal bores for non-rotatably coupling first and second ends  46   a  and  46   b  of crank spindle  30  thereto. 
     The crank spindle  30  has a center section  52  located between first and second ends  46   a  and  46   b . Center section  52  has a pair of annular raised portions with first and second annular grooves  54   a  and  54   b  formed therein for receiving bearing members  34   a  and  34   b . Also a pair of races  56   a  and  56   b  are formed on the sides of grooves  54   a  and  54   b  for retaining bearing members  34   a  and  34   b  therein, respectively. As explained later in more detail, annular grooves  54   a  and  54   b  as well as the remaining portion of the outer surface  48  of center section  52  is formed by cold rolling crank spindle  30  between a pair of dies  90  and  91 . 
     The grooves  54   a  and  54   b  of crank spindle  30  are grooves of a circular cross-section for supporting steel balls or bearing members  34   a  and  34   b . The diameter of the grooves  54   a  and  54   b  of crank spindle  30  are substantially equal to the diameter of the steel balls or bearing members  34   a  and  34   b  or slightly larger than the diameter of the steel balls or bearing members  34   a  and  34   b . Accordingly, bearing members  34   a  and  34   b  can freely rotate and move about the circumference of annular grooves  54   a  and  54   b.    
     Referring now to FIG. 4, a partial longitudinal cross-sectional view of the tubular outer member or shell  32  for the first bearing assembly  12  is illustrated with longitudinal axis O extending therethrough. Tubular outer member  32  has a first open end  58   a,  a second open end  58   b,  an internal surface  60  and an external surface  62 . The internal and external surfaces  60  and  62  extend between the first and second open ends  58   a  and  58   b  of tubular outer member  32 . Preferably, tubular outer member  32  is constructed of a conventional metallic material. Tubular outer member  32  is initially a tubular or cylindrical sleeve  32   a  as seen in FIG.  5 . The sleeve  32   a  is cold-rolled, as explained below, to form the profile of the tubular outer member  32  as seen in FIG.  4 . 
     In particular, the internal surface  60  is contoured to form a pair of cylindrical end sections  64   a,    64   b  and three center cylindrical sections  65 ,  66  and  67  spaced distances S 1 , S 1 ′ and S 1 ″ from longitudinal axis O, respectively. The cylindrical end sections  64   a  and  64   b  are substantially identical to each other but mirror images of each other. Each of the cylindrical end sections  64   a  and  64   b  has an annular groove  68   a  and  68   b,  spaced a distance S 2  from longitudinal axis O, formed therein for engaging bearing members  34   a  and  34   b . Preferably, the grooves  68   a  and  68   b  are grooves of a circular cross-section for supporting bearing members  34   a  and  34   b . The diameter of the curved surfaces forming the grooves  68   a  and  68   b  are preferably identical to the diameter of the steel balls or bearing members  34   a  and  34   b  or slightly larger than the diameter of the steel balls or bearing members  34   a  and  34   b.    
     Still referring to FIG. 4, external surface  62  of tubular outer member  32  has a pair of cylindrical end sections  74   a,    74   b  and three cylindrical center sections  75 ,  76  and  77 . The cylindrical end sections  74   a  and  74   b  have annular bulges  78   a  and  78   b,  respectively, which are located opposite annular grooves  68   a  and  68   b . Likewise, the cylindrical center sections  75 - 77  of external surface  62  are opposite the center cylindrical surfaces  65 - 67  of the internal surface  60 . In other words, when the sleeve  32   a  (FIG. 5) is deformed to create outer tubular member  32  (FIG.  4 ), the external surface  62  is deformed to correspond to the deformation of the internal surface  60 . 
     Referring now to FIG. 2, retainers  36   a  and  36   b  are generally annular ring-shaped members, which are preferably constructed of a synthetic resin such as the synthetic resin Duran. Retainers  36   a  and  36   b  are relatively conventional members, which are well known in the art. Thus, retainers  36   a  and  36   b  will not be discussed or illustrated in detail herein. Basically, retainers  36   a  and  36   b  are formed of an annular ring-shaped portion and with seven axially extending flanges or spacers which are circumferentially spaced around the ring portion for receiving steel balls or bearing members  34   a  and  34   b  therebetween. The retainers  36   a  and  36   b  serve to maintain a constant interval between the steel balls or bearing members  34   a  and  34   b , the spaces between the flanges slightly exceeds the diameter of the bearing members to accommodate their rotation. 
     Referring again to FIG. 2, seals  38   a  and  38   b  are preferably annular members constructed of a resilient and/or elastic material such as conventional rubber seals. The seals  38   a  and  38   b  are ring-shaped such that the internal diameter of the seal is slightly smaller than the crank spindle  30 . Thus, seals  38   a  and  38   b  are designed to deform around the outer surface  48  of the crank spindle  30  to create a seal for preventing contaminants from passing between the interface thereof. The outer diameters of seals  38   a  and  38   b  are preferably slightly larger than the cylindrical end sections  64   a  and  64   b  of the internal surface  60  such that seals  38   a  and  38   b  are deformed slightly inwardly when they engage the internal surface  60  of tubular outer member  32 . Thus, contaminants are prevented from passing between the interface of internal surface  60  and the external surface of seals  38   a  and  38   b.    
     First and second adapters  40   a  and  40   b  are slightly different from each other. However, these differences are inconsequential as they relate to the present invention. Accordingly, corresponding reference numerals will be utilized to depict corresponding parts of the first and second adapters  40   a  and  40   b . Basically, adapters  40   a  and  40   b  are tubular members having external threads  80   a  and  80   b,  an external flange  82   a  and  82   b,  an internal flange  84   a  and  84   b  and a plurality of projections  86   a  and  86   b.    
     External threads  80   a  and  80   b  are designed to engage the internal threads of the bottom bracket shell of the bicycle frame  20  to fixedly secure the bearing assembly  12  thereto. When adapters  40   a  and  40   b  are threaded into the bottom bracket shell of the bicycle frame  20 , the external flanges  82   a  and  82   b  engage the bottom bracket shell  24  of bicycle frame  20 , while the internal flanges  84   a  and  82   b  engage the first and second ends  58   a  and  58   b  of the tubular outer member  32 . In this position, axial movement of the bearing assembly  12  is prevented relative to the bottom bracket shell of frame  20 . Moreover, longitudinal movement of tubular outer member  32  is also prevented. More specifically, tubular outer member  32  is sandwiched between first and second adapters  40   a  and  40   b  to prevent any axial movement relative to the bottom bracket shell  24  or crank spindle  30 . Projections  86   a  and  86   b  are radially extending flanges that are equally spaced about the circumference of the internal surface of the adapters  40   a  and  40   b . The projections  86   a  and  86   b  are designed to be engaged by a spanner at circumferential spaced apart positions for threading adapter  40   a  and  40   b  into the bottom bracket shell of bicycle frame  20 . 
     Referring now to FIG. 6, the method of manufacturing crank spindle  30  will now be described. First, the crank spindle  30  is manufactured by casting the general shape of the spindle such that it has the general overall shape of the end product. Next, the rough spindle is machined to form the threaded bores  50  at each of the ends of the spindle as well as to remove any imperfections from the casting operation. Then the machined spindle is placed between a pair of dies  90  and  91  to form the grooves  54   a  and  54   b  and the races  56   a  and  56   b  in the outer surface  48 , as schematically shown in FIG.  6 . 
     The first die  90  is a cylindrical die with a pair of annular bulges  92   a  and  92   b  having a circular cross-section. These bulges  92   a  and  92   b  are designed to form the grooves  54   a  and  54   b . The second die  91  can be either a stationary die or a rotating die. The second die  91  has a pair of recesses  93   a  and  93   b  that correspond to the location of the grooves  54   a  and  54   b  and the races  56   a  and  56   b , which are being formed on the outer surface  48  of crank spindle  30 . The rotating die  90  is move to press annular bulges  92   a  and  92   b  against the outer surface  48  of crank spindle  30  to begin forming grooves  54   a  and  54   b . The rotation of die  90  causes crank spindle  30  to rotate therewith. The die  90  is moved slowly relative to die  91  such that with each rotation of crank spindle  30  and die  90 , grooves  54   a  and  54   b  become gradually deeper and deeper. In other words, as die  90  and/or  91  rotate, the crank spindle  30  also rotates to form grooves  54   a  and  54   b . The spindle  30  and die  90  are continuously rotated until the desired depth and shape of groove  54   a  and  54   b  are obtained. On each side of the grooves  54   a  and  54   b  are ball races  56   a  and  56   b , which are also formed. The recesses  93   a  and  93   b  of second die  91  are shaped to allow ball races  56   a  and  56   b  to be deformed into the recesses  93   a  and  93   b  of die  91 . Once the final shape is formed, the crank spindle  30  can be treated with normal heat treating techniques to obtain the desired hardness. 
     Accordingly, this procedure creates a very fine surface within the grooves  54   a  and  54   b . In fact, this operation performs a polishing effect along the grooves  54   a  and  54   b . Also, while grooves  54   a  and  54   b  are being firmed, the ball races  56   a  and  56   b  are also being simultaneously formed. This makes the pitch, parallelism and the concentricity of the grooves  54   a  and  54   b  and ball races  56   a  and  56   b  very stable. 
     Referring now to FIGS. 4,  5  and  6 , the method of manufacturing tubular outer member  32  will now be described. The tubular outer member  32  is also formed by cold rolling. First, the tubular outer member  32  is manufactured by casting a sleeve  32   a  as seen in FIG.  5 . Next, the rough sleeve  32   a  is machined to remove any imperfections and create any necessary formations needed thereon. Then, the machined sleeve  32   a  is cold-rolled to form its final shape as shown in FIG.  4 . In particular, as shown in FIG. 7, the machined sleeve  32   a  is inserted into a jig assembly  94  to be deformed. Jig assembly  94  has a tubular bore  95  having at least three cylindrical sections for accommodating the final shape of tubular outer member  32 . Now, a special forming die  96  is inserted into the internal bore of the sleeve  32   a . This special die  96  includes three rollers  97  and a conically tapered expander  98 . The three rollers  97  have external surfaces that correspond to the final profile of the internal surface  60  of tubular outer member  32 . The tapered expander  98  is located in the center between the three rollers  97 . The rollers are spaced approximately 120° apart from each other around the axis of expander  98 . The expander  98  is rotated which in turn causes the three rollers  97  to rotate about their axis, as well as to orbit or rotate about the center axis of the expander  98 . Initially, the rollers  97  merely contact the cylindrical surface of the sleeve  32   a  such that the first rotation barely deforms the internal surface of sleeve  32   a . The expander  98  is slowly moved axially so as to cause the rollers  97  to move radially outwardly to begin forming the internal surface  60  of tubular outer member  32 . The expander  98  is moved very slowly and incrementally such that the internal surface  60  is gradually formed with each rotation of the rollers  97  about the inner diameter of the internal surface  60  of tubular outer member  32 . Once the final shape is formed, the tubular outer member  32  can be treated with normal heat treating techniques to obtain the desired hardness. 
     Accordingly, this procedure creates a very fine surface within the grooves  68   a  and  68   b . In fact, this operation performs a polishing effect along the grooves  68   a  and  68   b . This makes the pitch, parallelism and the concentricity of the grooves  68   a  and  68   b  very stable. 
     Once the crank spindle  30  and tubular outer member  32  are created in accordance with the present invention, the crank spindle  30  is inserted into the bore of tubular outer member  32  so as to be located between the outer surface  48  of spindle  30  and the internal surface  60  of tubular outer member  32 . In particular, the bearing members  34   a  and  34   b  are first positioned within the grooves  54   a  and  54   b  and grooves  68   a  and  68   b  on one side of the spindle  30  and on one side of the internal surface  60  of tubular outer member  32 . Then, the bearing members  34   a  and  34   b  are moved around the grooves  54   a  and  54   b  of crank spindle  30  to be substantially equally spaced apart from each other within the grooves  54   a  and  54   b  and  68   a  and  68   b . 
     Now, the retainers  36   a  and  36   b  are inserted through the open ends  58   a  and  58   b  of tubular outer member  32  and over the ends  50   a  and  50   b  of crank spindle  30  to hold the bearing members  34   a  and  34   b  in their correct positions. Once the retainers are in place, seals  38   a  and  38   b  are inserted over the ends  50   a  and  50   b  of crank spindle  30  and through the open ends  58   a  and  58   b  of tubular outer member  32 . This results in the external surfaces of the seals  38   a  and  38   b  being deform against the cylindrical end sections  64   a  and  64   b  of the internal surface  60  of the tubular outer member  32 . The inner surfaces of seals  38   a  and  38   b  are also deformed against the outer surface  48  of crank spindle  30 . 
     Finally, with the crank spindle  30  and the tubular outer member  32  positioned within the bottom bracket shell  24  of the bicycle frame  20 , the pair of adapters  40   a  and  40   b  are threaded into the bottom bracket shell  24  of the bicycle frame  20  to fixedly secure bearing assembly  12  to bicycle frame  20 . This completes the installation of the bearing assembly  12 . Of course, now the cranks  26  can be installed onto the crank spindle  30  via fixing bolts  42  in a conventional manner. 
     Referring now to FIG. 9, a partial cross-sectional view of the second bearing assembly  14  is illustrated in accordance with the present invention. This second bearing assembly  14  is constructed in substantially the same manner as the first bearing assembly  12  of FIGS. 1-8, discussed above, except that second bearing assembly  14  is a bicycle hub. In view of the similarities between second bearing assembly  14  and first bearing assembly  12 , the second bearing assembly  14  will not be discussed or illustrated in detail herein. Rather, the description of the parts of the first bearing assembly  12 , which are similar to the parts second bearing assembly  14 , applies to the parts second bearing assembly  14 . 
     Bearing assembly  14  forms the front hub of the front bicycle wheel  22  for rotatably coupling front bicycle wheel  22  to bicycle frame  20 . Bearing assembly  14  basically includes an elongated inner member or hub axle  130 , a tubular outer member or hub shell  132 , two sets of bearing members  134   a  and  134   b , a pair of retainers or cages  136   a  and  136   b , a pair of seals  138   a  and  138   b  and a pair of hub flanges  140   a  and  140   b.    
     Hub axle  130  is designed to rotate within tubular outer member  132  via bearing members  134   a  and  134   b . Accordingly, hub axle  130  acts as an inner race, which is fixedly coupled to frame  20 , while tubular outer member  132  acts as an outer race, which is fixedly coupled to wheel  22 . The bearing members  134   a  and  134   b  are preferably steel balls with each set of bearing members  134   a  and  134   b  having seven steel balls therein. Of course, it will be apparent to those skilled in the art from this disclosure that fewer or more steel balls can be utilized in each set of bearing members  134   a  and  134   b.    
     Hub axle  130  is an elongated member having a first end  146   a , a second end  146   b  and an outer surface  148  extending between first end  144   a  and second end  146   b . First and second ends  146   a  and  146   b  are threaded for threadedly receiving hub fasteners  128   a  and  128   b  to fixedly secure wheel  22  to bicycle frame  20 . While hub fasteners  128   a  and  128   b  are shown as hub nuts, it will be apparent to those skilled in the art from this disclosure that the hub fasteners can be a quick release lever and a quick release nut. 
     Hub axle  130  has a center section  152  located between first and second ends  146   a  and  146   b . Center section  152  has a pair of annular raised portions with first and second annular grooves  154   a  and  154   b  formed therein for receiving bearing members  134   a  and  134   b . Also a pair of races  156   a  and  156   b  are formed on the sides of grooves  154   a  and  154   b  for retaining bearing members  134   a  and  134   b  therein, respectively. 
     Grooves  154   a  and  154   b  of hub axle  130  are grooves of a circular cross-section for supporting steel balls or bearing members  134   a  and  134   b . The diameter of the grooves  154   a  and  54   b  are substantially equal to the diameter of the steel balls or bearing members  134   a  and  134   b  or slightly larger than the diameter of the steel balls or bearing members  134   a  and  134   b . Accordingly, bearing members  134   a  and  314   b  can freely rotate and move about the circumference of annular grooves  154   a  and  154   b.    
     The tubular outer member or hub shell  132  has a first open end  158   a , a second pen end  158   b , an internal surface  160  and an external surface  162 . The internal and external surfaces  160  and  162  extend between the first and second open ends  158   a  and  158   b  of tubular outer member  132 . Preferably, tubular outer member  132  is constructed of a conventional metallic material. Tubular outer member  132  is initially a tubular or cylindrical sleeve. The sleeve is cold rolled to form the profile of the tubular outer member  132  as seen in FIG.  9 . 
     In particular, the internal surface  160  is contoured to form a pair of annular groove  168   a  and  168   b  formed therein for engaging bearing members  134   a  and  134   b . Preferably, the grooves  168   a  and  168   b  are grooves of a circular cross-section for supporting bearing members  134   a  and  134   b . The diameter of the curved surfaces forming the grooves  168   a  and  168   b  are preferably identical to the diameter of the steel balls or bearing members  134   a  and  134   b  or slightly larger than the diameter of the steel balls or bearing members  134   a  and  134   b.    
     External surface  162  of tubular outer member  132  has a pair of annular bulges  178   a  and  178   b,  respectively, which are located opposite annular grooves  168   a  and  168   b . In other words, when the sleeve is deformed to create outer tubular member  132 , the external surface  162  is deformed to correspond to the deformation of the internal surface  160 . 
     Retainers  136   a  and  136   b  are generally annular ring-shaped members, which are preferably constructed of a synthetic resin such as the synthetic resin Duran. Retainers  136   a  and  136   b  are relatively conventional members, which are well known in the art. Thus, retainers  136   a  and  136   b  will not be discussed or illustrated in detail herein. Basically, retainers  136   a  and  316   b  are formed of an annular ring-shaped portion and with seven axially extending flanges or spacers which are circumferentially spaced around the ring portion for receiving steel balls or bearing members  134   a  and  134   b  therebetween. The retainers  136   a  and  136   b  serve to maintain a constant interval between the steel balls or bearing members  134   a  and  134   b , the spaces between the flanges slightly exceeds the diameter of the bearing members to accommodate their rotation. 
     Seals  138   a  and  138   b  are preferably annular members constructed of a resilient and/or elastic material such as conventional rubber seals. The seals  138   a  and  138   b  are ring-shaped such that the internal diameter of the seal is slightly smaller than the hub axle  130 . Thus, seals  138   a  and  138   b  are designed to deform around the outer surface  148  of hub axle  130  to create a seal for preventing contaminants from passing between the interface thereof. The outer diameters of seals  138   a  and  138   b  are preferably slightly larger than the internal surface  160  such that seals  138   a  and  318   b  are deformed slightly inwardly when they engage the internal surface  160  of tubular outer member  132 . Thus, contaminants are prevented from passing between the interface of internal surface  160  and the external surface of seals  138   a  and  138   b.    
     Hub flanges  140   a  and  140   b  can be slightly different from each other. However, these differences are inconsequential as they relate to the present invention. Accordingly, corresponding reference numerals will be utilized to depict corresponding parts of the first and second hub flanges  140   a  and  140   b . Basically, hub flanges  140   a  and  140   b  are tubular members that are frictionally secured on tubular outer member  130 . Hub flanges  140   a  and  140   b  have outer flanges  182   a  and  182   b  and inner flanges  184   a  and  184   b , respectively. The outer flanges  182   a  and  182   b  have a plurality of holes for coupling spokes or the like thereto. Inner flanges  184   a  and  184   b  abut against the ends of the tubular outer member  132 . 
     Turning now to third bearing assembly  16 , rear wheel  22  is rotatably coupled to frame  20  by the third bearing assembly  16 . The third bearing assembly  16  is substantially identical to the second bearing assembly  14  except that third bearing assembly  16  is a rear or free hub. Accordingly, it will be understood by those skilled in the art that the construction and method of manufacturing first bearing assembly  12  and second bearing assembly  14  can also be applied to that the construction and method of manufacturing third bearing assembly  16 . Thus, the third bearing assembly  16  will not be discussed or illustrated in detail herein. 
     While several particular embodiments have been chosen to illustrate the present invention, it will be understood by those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing description of the preferred embodiments of the present invention is provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.