Patent Document

BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The invention relates to paired spoke bicycle wheels having an optimized rim extrusion and spoke pacing which enables lighter and stronger wheels for improved performance. By spacing tensioned spokes optimally, mechanical stress on the rim structure is minimized between rim failure from high stress concentration and rim distortion from longer distances between spokes. This enables lighter and stronger rims, the rims being optimized having a sectional shape of an irregular pentagon.  
           [0003]    2. Description of Related Art  
           [0004]    Several pieces of prior art describe the potential, and as yet, not optimized advantages of paired spoke bicycle wheels over a century of development. As early as 1889, the U.K. patent to Lovelace No. 3056 (Feb. 20, 1889) describes paired spokes: “the spokes the each are screwed into the hub flange is w, in a line which is a tangent to a circle somewhat smaller than the said flange, and two spokes, that is to say, one from each end of the hub, meet at the same point in the rim as shewn clearly in FIG. 5 . . . ”. The motivation for paired spokes is explained, continuing: “thus bringing the strain to bear equally upon the rim and avoiding the liability to buckle, which is attendant on the usual arrangement”.  
           [0005]    Another paired spoke reference is French patent No.1,019,285 issued to Menet dated Jan. 20, 1953. A copy of an English translation of Menet was filed in the application which issued as U.S. Pat. No. 5,931,544. It is on this translation that the explanation herein relies, although the terminology is also recognized as consistent with the disclosure in Menet&#39;s drawings.  
           [0006]    Menet describes a bicycle wheel having, among other features, “. . . on the rim on both sides of the median plane, perpendicular to the axis of the wheel, and arranged more or less in a straight line parallel to the axis of said wheel . . . ”. Menet teaches a hub, axle and paired spokes: “the spokes are distributed on the rim in groups of two, having their . . . points of attachment on the hub of the wheel almost on the same line . . . ”. Menet describes tensioned, paired spokes, with two ends: “. . . on the threaded ends of the spokes, nuts  4  are screwed on in the usual manner . . . . On the other end the two spokes of the same group will advantageously be fastened to the hub of the wheel, at points 5 . . . ”.  
           [0007]    While Lovelace described the advantage as reduced “strain”, Menet&#39;s translation uses a more dynamic description of the purpose of paired spoking: “thus increasing the lateral rigidity of the wheel and freeing the rim from the abnormal torsional forces to which normal rims are subjected when used until it becomes possible to considerably ease the strain on the rims without risk of warping” and “to attain as perfect a symmetry as possible of the spokes on [on] both sides of a median plane, perpendicular to the axis of the wheel”.  
           [0008]    Bicycle wheels are, of course subject to both static loads and dynamic forces, and the “strain” observed by Lovelace necessarily translates to transverse changes at the rim as a tensioned spoke wheel, bearing the mass of the bicycle and rider, and acceleration and deceleration forces, contacts pavement while rolling. These dynamic forces are Menet&#39;s “torsional forces to which . . . rims are subjected when used”. Measurements of this are suggested in the aforementioned U.S. Pat. No. 5,931,544, although the inventor herein has been unable to reproduce all of the tests described in U.S. Pat. No. 5,931,544, or its parent, U.S. Pat. No. 5,104,199. However, it is believed that the tests in these two patents were static lateral load tests, not dynamic tests. It is believed that the lack of precision resulted in rims that were unduly heavy for their strength because of their closely spaced spoked design.  
           [0009]    Two other problems were observed in the prior art. These are not believed to have been solved by the prior art.  
           [0010]    First, paired spokes, while producing a more even strain having advantages on a rotating wheel, have the considerable disadvantage of concentrating that strain in a small area on the rim. Menet suggests a reinforcing boss: “To reinforce the fastening of the spokes, 4 two-holed bracket  7  can be inserted between the nuts and the rim”. It will be appreciated that adding material and pieces to a structure optimized for strength and weight is disadvantageous, in addition to the added expense and other inefficiency of having added components needed.  
           [0011]    Second is the difficulty in placing paired spokes that are perfectly paired precisely opposite one another on a narrow rim. A second Lovelace patent, No. 5968 Apr. 19, 1890 anticipated one of the embodiments of Dietrich &#39;544: “The arrangement of spokes shown in FIGS. 4 and 5, of my aforesaid drawings cannot conveniently be applied to a narrower rim, as there is not room for the spokes to be placed opposite each other; in such cases I make two holes, one in front of the other, and near together for each pair of spokes going to opposite sides of the hub, this gives practically all the advantages of the former arrangement, while it enables the method to be applied to narrow rims.” The “aforesaid drawings” are those in Lovelace No. 3056. The circumferential offset is shown in FIGS. 6 and 7 of the Lovelace 5968 patent and described: “In the improved arrangement for attaching spokes to the wheel rims, I make two holes in the rim one in front of the other and near together, but slightly on the skew, that is to say the holes are made in a line which is diagonal to the rim, the holes are countersunk on the inside to receive the heads of the spokes and one spoke of each pair goes to one end of the hub and the other spoke to the other end, as described in my prior specification No. 3056 of 1899.” Lovelace 5968 if scaled to the proportion of modem road bicycle wheels, of about one inch, would provide circumferential spacing of about 0.3 inches.  
           [0012]    U.S. Pat. No. 1,474,631 issued Nov. 20, 1923 to House also shows a combination of paired ( 13 ,  15 ) and unpaired ( 14 ) spokes on a wheel. House explains that the heavy loads on wagons or artillery carriages subject spoked wheels to forces that impose lateral or transverse loads as the wheels rotate.  
           [0013]    Certain production paired spoke rims made by the assignee of this application, and which are outside the scope of the teachings of the aforementioned Dietrich &#39;544 patent have had spokes spaced about 28 mm (1.1 inches) to about 33 mm (1.3 inches). While functional, these wheels need to rely on the rim rigidity to reduce the tendency towards wheel wobble, as opposed to the invention which optimizes for reducing both stress and wobble tendency. Embodiments of Dietrich-style paired spoke wheels have typically been limited to not greater than three quarters of 1 inch (19.05 mm) while standard, non-paired spoke wheels typically have spacing of around 2 inches.  
           [0014]    Other commercial paired spoke embodiments have been sold, but these mount spokes in a reversed manner such that the spoke head is in the side wall rim and the nipple is at the hub. These are typified in U.S. Pat. Nos. 6,196,638, 6,213,562 and 6,234,580, or with crossed wire spokes penetrating the side wall of the rim, U.S. Pat. Nos. 6,158,819 and 6,231,128. These provide a much different solution than that of the instant invention, putting more material to support the rim, at the expense of a deeper, hence heavier, structure, and using a complex hub.  
           [0015]    The spoking of the invention solves the two problems of varying transverse loads upon rotation under axle loads, while also avoiding concentration of stress and strain on the structure of the rim by pairing spokes but spacing them sufficiently apart to decrease the loads on the rim structure to levels which permit thinner, lighter rims.  
           [0016]    Rim sections also have need for optimized form, particularly for rear wheels used on bicycles having modem multiple speed cog sets. While symmetrically formed and symmetrically spoked rear wheels have been adequate for geared bicycles typically having five rear cogs—when multiplied by two front chain wheels comprising the “ten speeds” of the post-war period through the late 1990&#39;s—contemporary gear mechanisms use as many as nine or ten speeds on the rear alone. The spacing required for these mechanisms require the spacing of the cog-side hub flange a considerable distance from the bicycle&#39;s “drop-outs” upon which the axle is clampingly affixed. Traditionally “dishing” the rear wheel using different length spokes enabled the clearance for the cogset, while still positioning the rim and tire on the centerline of the bicycle. Positioning the on the centerline is important for proper performance, particularly braking and steering. Krampera, U.S. Pat. No. 5,228,756 discloses a not altogether satisfactory solution of drilling spoke holes off center, on an occasionally twisted rim having an otherwise generally symmetric section. The instant invention is shaped to permit the spokes to fit holes that are substantially equidistant from the rim walls as they intersect the spoke bed, thereby eliminating the need for excess material and the detrimental mass and differential strength properties thereof that result from the asymmetrically located holes of Krampera. Krampera&#39;s alternatives use extrusions having webs of varying thickness to compensate for his asymmetry, which cause stress concentration and result in unacceptably heavy or alternatively, unacceptably strong rims. The instant rim will be referred to as an offset rim, to distinguish from the asymmetric rim of Krampera, as the instant rim optimizes weight, strength and geometry.  
         SUMMARY OF THE INVENTION  
         [0017]    The invention pairs spokes but spaces them sufficiently apart to decrease the loads on the rim structure to levels which permit thinner, lighter rims. This arrangement minimizes varying transverse loads imposed on rotation under axle loads, while also minimizes concentration of stress and strain on the structure of the rim by spacing the spokes 26 mm (1.02 inches) apart. It will be understood that within the limits of the measurements provided, 26 mm mathematically converts to slightly more than 1 inch.  
           [0018]    The new rim design of the invention increases the stiffness and durability of our wheelset while maintaining a lightweight rim. An offset spoke bed rim profile minimizes the difference in spoke angle between the drive side and nondrive side spokes while using a common brakewall width and height allows quick wheel changes without brake pad adjustment and consistent braking performance  
           [0019]    In addition to rear rim profile, ideal spoke hole spacing, termed circumferential offset or skew in the prior art, is important for optimizing strength, minimizing weight and maximizing performance. Paired spokes additional provide ease of assembly and adjustment in that conventional wheels require adjusting three spoke tensions to adjust a hob or wobble in the rim, two drive, or right spokes and a left, or nondrive spoke.  
           [0020]    The invention takes advantage of the discovery that at a spacing, skew or circumferential offset of 26 mm (1.02 inches) stress on the spoke bed is minimized yet distortion on the rim from a radial plane—the center plane of the wheel—is also minimized, these determinations, therefore, enabling lighter and better performing rims. By comparison with prior art spacing, such as that disclosed in Dietrich &#39;544, of 9 mm, stress in is reduced by sixteen percent (16%).  
           [0021]    This optimization becomes particularly problematic when dealing with a rear wheel. One condition is the desirability in manufacturing for a minimum number of different size parts. In prior art hubs, for example, one solution to the different performance of a dished drive wheel was the use of different sized flanges and potentially different sized spokes. The instant invention enables the use of similarly sized flanges and spokes for improved performance and manufacturability. Additionally, it is valuable to enable machine wheel building, but prior art hubs with spoke holes in line were not adaptable to machine wheel building because of the clearances involved. Offsetting spoke holes in the flanges circumferentially as described herein enables machine wheel building.  
           [0022]    Because of the need to provide clearance for a cogset and the incumbent variations between the left and right side of the wheel, it has also been determined that it is possible to manufacture wheels automatically and with greater economy and efficiency by using spokes of the same length. Traditionally, hub flange spoke holes on paired spoked wheels have been coaxial, that is, with a common centerline, perpendicular to the centerline of the axle. The front wheel in the invention uses this arrangement. Traditional non-paired wheels used spoke holes evenly spaced around the flange. These arrangements all required the use of different spoke lengths to achieve the required “dish” of the rear wheel. However, laced, crossed spokes as shown herein can advantageously use same length spokes by imposing a slight radial offset. This, coupled with the rim offset, enables use of same-length spokes.  
           [0023]    In addition to the circumferential offset, improvements permitted by this invention over prior paired spoke and nonpaired spoke wheels include the use of the special rear rim profile that, in a finished wheel, permits improved spoke alignment to effectively reduce “dish” imposed by different length and differently angled spokes, and instead achieve centered alignment of the braking surfaces and tire with combined spoke hole, flange and rim profile orientation. Common or near-common left and right spoke angles in a sectional view can reduce tension disparities between left and right side, or drive and nondrive side, spokes. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0024]    [0024]FIG. 1 is a sectional view of a front bicycle wheel of the invention.  
         [0025]    [0025]FIG. 2 is a sectional view of a rear bicycle wheel of the invention.  
         [0026]    [0026]FIG. 3 is an elevation of a front bicycle wheel of the invention.  
         [0027]    [0027]FIG. 4 is a fragmentary view of the hub, spoke and rim arrangement of the invention, with some spokes eliminated.  
         [0028]    [0028]FIG. 5 is a sectional view of a rear hub.  
         [0029]    [0029]FIG. 6 is a left side plan view of a rear hub. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0030]    A front bicycle wheel  10  is typically formed with a rim  12  laced to a hub  14  with left and right sets of spokes  16 ,  18 . A hub  14  has left and right flanges  20 ,  22  spaced apart by a typically, generally cylindrical body portion  24 . The cylindrical body portion  24  has a bore  26  with bearing assemblies  28 ,  30  at either end  32 ,  34 . The bearing assemblies rotatably carry an axle assembly  36 . Bearings axles and the related components are advantageously designed to use generally standard, replaceable and serviceable units, known to one of ordinary skill.  
         [0031]    Each left and right spoke  16 ,  18  each preferably have heads  40 ,  42  elongate center portions  44 ,  46  and threaded end portions  48 ,  50 . End portions  48 ,  50  are received by left and right spoke nipples  52 ,  54 . It will be understood that the described spoke and nipple arrangement has significant economies, represent a wealth of experience in dealing with their strength and are well adapted to automated wheel building machinery. However, to the extent that the invention does not require a specific orientation of head and adjustment and tensioning, other spoke tensioning arrangements are known, provided there is adequate material strength and durability. Thus, arrangements such as a Lovelace spoke with the head at the rim and the threads engaging the hub, modernized for current materials technology.  
         [0032]    Typical rims  12  have a spoke bed or web,  60  a pair of outwardly extending left and right walls  62 ,  64  and a tube bed or web  66  with tire bead receiving left and right flanges  68 ,  70  extending outwardly therefrom. Variations in form include rims for tubular tires which have no flanges and are therefore of a generally box section, albeit with a concave tube bed or web, and more aerodynamic sections in which the walls smoothly and perhaps elliptically taper to a narrower radiused spoke bed. Finally, walls  62 ,  64  may be formed in intermediate portions  72 ,  74  and braking surface portions  76 ,  78 . The teachings here are expected adaptable to various forms such as these.  
         [0033]    A rear bicycle wheel  110  is typically formed with a rim  112  laced to a hub  114  with left and right sets of spokes  116 ,  118 . A hub  114  has left and right flanges  120 ,  122  spaced apart by a typically, generally cylindrical body portion  124 . The cylindrical body portion  124  has a bore  126  with bearing assemblies  128 ,  130  at either end  132 ,  134 . The bearing assemblies rotatably carry an axle assembly  136 .  
         [0034]    On a rear wheel,  110 , a drive member  138  carries the cogs through which motive force is transferred from the rider to the wheel  110 . As is known to one of ordinary skill, the drive member  138  that predominates on contemporary high performance bicycles has a ratchet internal with the assembly that comprises hub  114 . Typically, these fit on splined members. Older, and bicycles of a lower performance design may have a drive member  138  that receives a freewheel that has a ratchet and cogs and typically threaded to the hub  114  at drive member  138 . Freewheels typically did not require the extreme wheel “dish” of the contemporary large capacity cogset. Nevertheless, the instant invention is not limited to a particular drive arrangement. Bearings axles and the related components are advantageously designed to use generally standard, replaceable and serviceable units, known to one of ordinary skill.  
         [0035]    Each left and right spoke  116 ,  118  each preferably have heads  140 ,  142  elongate center portions  144 ,  146  and threaded end portions  148 ,  150 . End portions  148 ,  150  are received by left and right spoke nipples or nuts  152 ,  154 . As with the front wheel, the spoke and nipple arrangement has significant practical advantages. Nevertheless, other spoke tensioning arrangements are known, provided there is adequate material strength and durability.  
         [0036]    The novel rear rim  112  has a spoke bed or web  160  which receives the spokes  116 ,  118  in nipples or nuts  152 ,  154 . Outwardly extending left and right walls  162 ,  164  are formed and arranged so that operating in conjunction with reducing the spacing of left and right flanges  120 ,  122 , enable the spokes  116 ,  118  meet at angles off the vertical that are closer than would be permitted with prior arrangements. The combination of these developments yields a tension disparity between the left and right side of sixty-seven percent (67%). Previous designs yield a tension disparity of one hundred twenty-seven percent (127%). A more durable wheel is achieved if the difference between the left and right side spoke tensions is minimized.  
         [0037]    Rear rim  112  has a tube bed or web  166  with tire bead receiving left and right flanges  168 ,  170  extending outwardly therefrom. Walls  162 ,  164  are preferably formed in intermediate portions  172 ,  174  and braking surface portions  176 ,  178 . The teachings here are expected adaptable to various forms with geometric adjustments such that different rim section shapes can be used—highly aerodynamic shapes for certain conditions, riding styles or preferences such as time trials or triathlons, more resilient shapes for rough conditions such as cobblestones or mountain bike use, and the like.  
         [0038]    Spoke bed  160  is offset to enable a profile of rim  112  which minimizes the difference in spoke angle between the spokes on the right or drive side  118  and the spokes on the left or nondrive side  116 . Preferably 0.060 inch is a desired offset. An advantage to this offset is that it permits a high strength spoke arrangement permits using a brakewall width and height common to a full line of bicycle wheel rims, which allows quick wheel changes without brake pad adjustment.  
         [0039]    As can be seen from the drawings, tube bed  160  spans walls  162 ,  164 . Preferably tire bead receiving left and right flanges  168 ,  170  extend outwardly from said walls  162 ,  164  at their intersection with said tube bed  160 . However, a sectional shape such as shown is readily adaptable to tubular or “sew-up” tires by omitting said flanges. It will be noted that the arc that defines tube bed  160  is on a center that is aligned with the centerline equidistant between braking surface portions  176 ,  178 .  
         [0040]    The geometry of left, or first intermediate portion  172  and right, and second intermediate portion  174  extends them outwardly from spoke bed  160  to said first and second braking surface portions  176 ,  178 , respectively, assuring that braking surface portions  176 ,  178  lie equidistant from the centerline of the bicycle itself for maximum brake and handling performance.  
         [0041]    It can be seen that the left, or first intermediate portion  172  extends outwardly the wheel center plane at an angle slightly off a parallel from the wheel center plane. By comparison, right, or second intermediate portion  174  extends outwardly from said center plane at an angle off a parallel from said center plane that is substantially greater than the angle of said left, or first intermediate portion  172 .  
         [0042]    The invention is based on determination of the ideal spacing for left and right spoke holes  180 ,  182  formed in spoke bed  160  to enable a strong and lightweight rim  112 . Certain advantages exist regarding paired spoke rims, in addition to those noted by prior art such as Lovelace and Menet, cited above. By pairing spokes  16 ,  18  and  116 ,  118  around a rim  12 ,  112 , a design can reduce the time and difficulty in building a wheel  10 ,  110  to minimize hop and wobble, critical for a machine built wheel  10 ,  110 . In a conventionally spaced wheel, it requires adjusting three spoke tensions to adjust a hop or wobble in the rim, two right or drive spokes and a left, or nondrive spoke or vice-versa. A paired spoke wheel,  10 ,  110  requires adjusting the tension in only two spokes  16 ,  116 , and  18 ,  118  for the same section of rim  12 ,  112 .  
         [0043]    With this in mind, it was determined that 26 mm (or about 1.02 inches) measured from the center of spokes  16 ,  116  to the center of spoke  18 ,  118  on the spoke bed  60 ,  160  is the closest spacing possible without increasing the stress on the spoke bed  60 ,  160  of the rim  12 ,  112 . At less than 26 mm spacing, the spoke tensions start to act together, creating a stress higher than any stress just one spoke can achieve. This arrangement results in a stress reduction on average of sixteen percent (16%) from a spacing of 9 mm.  
         [0044]    This spacing of spokes  16 ,  116 ,  18 ,  118  in this manner maximizes the stiffness of the rim  12 ,  112  in both radial and lateral planes. The thickness of spoke bed  60 ,  160  working in conjunction with the outer profile from above, the angles of the sidewalls  62 ,  162  and  64 ,  164 , their shapes as between rim intermediate portions  72 ,  172 ,  74 ,  174  and the radii as the merge into braking surface portions  76 ,  176  and  78 ,  178  are optimize until the lightest, stiffest rim  12 ,  112  possible is achieved. However, unless both the stress is minimized and the tendency to wobble under load is also minimized—spacing neither too close, because stress is increased, nor too far because wobble will increase—the lightness of the rim is sacrificed, because either strength at the spoke holes or stiffness will need to be increased by adding more material.  
         [0045]    The offset of the flange spoke holes  184 ,  186  between the left and right side flanges  120 ,  122  of a rear hub is a result of the spacing between the spoke holes  180 ,  182  in the rim  112  and a desire to manufacture the wheel  110  with a minimal variation in spoke lengths for a given wheel. If a wheel is made with perfectly paired spokes at the rim  112 , a spoke from the left side flange meets at the rim in the same location as a spoke from the right side flange, then the offset between the spoke holes on the left side flange to the spokes holes on the right side flange can be zero degrees (0°). The further that the spokes  116 ,  118  are spaced apart from each other at the rim  112 , the greater the spoke hole circumferential offset that is required to achieve a wheel built with just two specific spoke lengths.  
         [0046]    It will be seen in FIG. 6 that the circumferential offset of flange spoke holes  184 ,  186 , one  184  being in the left flange  120 , and the other  186  being in the hidden right flange  122 , are offset six degrees (6°), although close to five degrees (5°) has been found acceptable, and, indeed, is shown in FIG. 4. It will also be noted that in the embodiment shown in FIG. 6, the holes  184 ,  186  are formed in a “bar-bell” shape, actually two round holes joined by a slot, which is particularly adapted to receive aerodynamic “bladed” spokes which have a flattened center portion aligned with the direction of wheel rotation for reduced air resistance.  
         [0047]    An added benefit to spokes  16 ,  116 ,  18 ,  118  offset at the rim  12 , 112  is that, unlike prior art paired spoke wheels of the types disclosed by the patents to Lovelace, Menet and Dietrich, automated manufacturing equipment can be used to make finished wheels with a spoke hole spacing between holes  80 ,  82  or  180 ,  182 , at the rim  12 ,  112  of 26 mm.  
         [0048]    On all rims that assignee manufactures to this specification (road and atb diameters), the effective angular dimension between the two spoke holes  180 ,  182  and a point  190  at the center of the rim is between five degrees (5°) and six degrees (6°), as described above with reference to FIG. 6. It will be understood that the geometry of FIG. 6 and the internal components of FIG. 5 can all be adapted to a front hub, by one of ordinary skill in the art.  
         [0049]    In order to limit building a rear wheel with two or less different spoke lengths, the circumferential spoke hole offset between the spoke holes  184  on the left side flange  120  and the spoke holes  186  on the right side flange  122  needs to be between five degrees (5°) and six degrees (6°). In prior commercial embodiments, a spacing for machine built wheels of 1.3 inches (33 mm) was typically used, which would require a seven degree (7°) circumferential offset. However, certain other production wheels did have spacing of as little as 28 mm (1.1 inches). Tolerance for hole placement between the left and right side flanges is ±one degree (1°).  
         [0050]    It has also been noted that improved spoke lines may be had by dishing flanges  120 ,  122  relative to the axle. By angling flanges  120 ,  122  about five degrees (5°) the flanges are brought more into alignment with the line of the spokes  116 ,  118  and reduced stress proximate spoke heads  140 ,  142  can be obtained. Because the hub flanges,  120 ,  122  are circular (FIG. 6) of course this angling actually forms a shallow conical shape. While FIG. 5 shows this with reference to the rear hub, the same can be advantageously used on a front hub.  
         [0051]    Placement of flange  120  spaced inwardly from end  132  a substantial distance as compared to the prior art location shown in broken lines. In practice this spacing is about sixty percent (60%) of the distance flange  122  is spaced inward from end  134 . The latter is a function of the size of the drive unit  138  which is increasing due to the adoption of nine and ten speed rear cogsets. This distance compares to only about forty-seven percent (47%) of the depth of a modern drive unit  138  for the prior art non-drive-side flange spacing. This is accomplished by including a much larger exterior bearing housing  190 , when compared to the prior art. Indeed, it will be noted in FIG. 6 that proximate end  132 , the bearing  128  is actually spaced outside flange  120 , while in the prior art, flanges had typically been located at the location of the flanges on both ends of the hub. In this manner both axle-bearing performance, and spoke leading optimization can occur in a dished rear or drive wheel.  
         [0052]    The invention enables a manufacturer to reduce the number of different parts needed to manufacture a wheel  10 ,  110 . Rear wheel  110  can be built with just one length spoke  116 ,  118 . An optimized hub  114  has the left and right side flanges  168 ,  170  displaced from the ideal vertical center of the hub  114 —equally spaced from ends  132 ,  134 . This hub  114  coupled with the a rim that uses a laterally offset spoke bed  160  allows us to achieve the assembly of a rear wheel  110  with one spoke length and thus one spoke if required.  
         [0053]    In addition to the width of flanges  168 ,  170  being located such that the angle between the spokes is about eighteen degrees (18°) and the half angle of each—the angle from the vertical—is about nine degrees (9°), loading and stress on the spokes near heads  140 ,  142 , where the spokes are formed with an approximately ninety degree (90°) bend, is further reduced by inclining flanges inwardly at about six degrees (6°). As flanges  140 ,  142  extend around hub  114 , this effectively defines a slightly conical form. The same six degree (6°) conical form can be used advantageously for front flanges  40 ,  42  to improve the lead of spokes  16 ,  18 .  
         [0054]    Rear rim  112  is formed by shortening left wall  162 , particularly intermediate portion  172 , and extending and right wall  164  considerably, particularly intermediate portion  174 , so that tire bead flanges  168 ,  170  and braking surface portions  176 ,  178  are substantially centered relative to the spokes  116 ,  118 , hub,  114  and hub flanges  140 ,  142 . In the preferred embodiment, to the extent tube bed or web  166  is slightly offset, its offset is limited to about 0.060 inches, a fairly small dimension, when compared to the prior art, and in fact, being less than the thickness of the typical metal spoke.  
         [0055]    The circumferential offset of spokes—most evident in the side, or elevational views—and the lateral offset of the rear rim—most evident in the sectional views, may be used independently or together. When used together they provide a maximized performance bicycle wheel, having the long desired advantages of light weight and strength, but also solving problems that have been noted, but not solved, by bicycle wheel designs for many years.  
         [0056]    While the present invention has been disclosed and described with reference to a these embodiments, it will be apparent, as noted above that variations and modifications may be made therein. It is also noted that the present invention is independent of the specific wheel, and is not limited to the specific wheels. It is, thus, intended in the following claims to cover each variation and modification that falls within the true spirit and scope of the present invention.

Technology Category: 7