Abstract:
A bicycle seat suspension assembly has a parallelogram pivoting linkage connecting the frame with the seat. The parallelogram linkage has a frame link, seat link, upper link, and lower link. An upper spring assembly pivotally engages the frame link on one end and extends up to pivotally engage the upper link. A lower spring assembly pivotally engages the frame link on one end and the lower link on the other end. The suspension assembly is movable between an uppermost position wherein the upper and lower spring assemblies are pre-compressed, and a second position wherein the upper and lower spring assemblies are further compressed. In some embodiments one or both of the spring assemblies have a compression spring that can be swapped out with another compression spring to adjust the spring rate of the assembly.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a Continuation of U.S. patent application Ser. No. 13/602,183 filed Sep. 2, 2012, which claims benefit of U.S. Provisional Application No. 61/530,086 filed Sep. 1, 2011, the entire disclosures of which are hereby incorporated by reference herein. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to vehicle suspension systems and methods and, more specifically, to suspension systems and methods configured to be used as with bicycles. 
         [0003]    A bicycle typically comprises a frame assembly, wheels, a seat, a fork, a handle bar, a pedal set, and a brake system. The fork is rotatably attached to the frame assembly, and a seat post of the seat is rigidly attached to the frame. A hub of the front wheel is attached to the fork, and a hub of the rear wheel is attached to the frame assembly. The pedal set is supported by the frame and connected to the rear wheel. A rider of the bike sits on the seat, grasps the handle bar with the hands, and rotates the pedals with the feet. 
         [0004]    Conventionally, the fork and frame assembly acted as rigid structures with respect to the seat and handle bar, and shocks were transmitted to the handle bar through the front wheel and the fork and to the seat through the rear wheel, the frame assembly, and the seat. These shocks were in turn transmitted to the rider, primarily through the handle bar and the seat. 
         [0005]    To reduce shocks on the rider, various suspension systems have been employed. Initially, the bicycle seat was padded, and springs were arranged between the seat and the frame to inhibit transmission of shocks to the rider sitting on the seat. Springs have also been arranged in the seat posts to inhibit transmission of shocks to the rider. Suspension seats and seat posts may be applied to a conventional bicycle having a rigid frame and fork but provide only limited shock absorption. 
         [0006]    Another class of bicycle suspension systems requires the modification of one or both of the frame and fork. 
         [0007]    One form of vehicle suspension system that requires a modified frame entirely eliminates the part of the frame that receives the seat post. The seat is instead supported on a spring arm extending backwards from the modified frame to inhibit transmission of shocks to the rider sitting on the seat. This variety of vehicle suspension system requires a radically modified frame and may not be applied to most bicycle frames on the market. 
         [0008]    Suspension systems have been applied to the fork to inhibit transmission of shocks to the rider&#39;s arms. In particular, the fork is divided into a steerer member and a fork member. The steerer member is connected to the handle bar, and the steerer member is connected to the fork member by a pneumatic suspension system arranged to resiliently oppose movement of the fork member to move relative to the steerer member along a fork axis. Suspension forks, while highly effective for off-road riding, are relatively heavy and expensive and are not preferred for use on bicycles built for road biking. 
         [0009]    Full suspension bicycles typically employ, in addition to a shock absorbing fork, a two piece frame assembly in which a first part of the frame is pivotably connected to a second part of the frame. The first part of the frame typically supports the seat and the pedal set, and the second part of the frame supports the rear wheel. In this case, a spring and/or pneumatic shock absorbing system is arranged to resist movement of the second part of the frame relative to the first part of the frame. Again, full suspension bicycles, while highly effective for off-road riding, are relatively heavy and expensive and are not preferred for road biking. 
         [0010]    The need exists for vehicle suspension systems and methods that effectively reduce shocks on the rider. 
       SUMMARY 
       [0011]    This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
         [0012]    The present invention may be embodied as a suspension system for a bicycle comprises a first adapter, a second adapter, at least one upper link plate, at least one lower link plate, an upper resilient system, and a lower resilient system. The at least one upper link plate is connected between the first and second adapters. The at least one lower link plate is connected between the first and second adapters. The upper resilient system is connected between the first and second adapters. The lower resilient system is connected between the first and second adapters. The upper and lower link plates allow movement of the first adapter from a first position to a second position relative to the first adapter. The upper and lower resilient systems are arranged to bias the second adapter into the first position. The upper and lower resilient systems resiliently oppose movement of the second adapter towards the second position. 
         [0013]    The present invention may also be embodied as a mounting system adapted to engage first and second seat rails of a bicycle seat comprising a base member, first and second clamp members, and a plurality of clamp screws. The base member defines first and second rail grooves. The first clamp member defines at a third rail groove. The second clamp member defines a fourth rail groove. One of the clamp screws secures the first clamp member to the base member such that the first and third rail grooves receive the first seat rail. One of the clamp screws secures the second clamp member to the base member such that the second and fourth rail grooves receive the second seat rail. 
         [0014]    The present invention may also be embodied as a method of forming a suspension system for a bicycle comprising the following steps. First and second adapters are provided. At least one upper link plate and at least one lower link plate are connected between the first and second adapters such that the upper and lower link plates allow movement of the first adapter from a first position to a second position relative to the first adapter. Upper and lower resilient systems are connected between the first and second adapters such that the upper and lower resilient systems bias the second adapter into the first position and resiliently oppose movement of the second adapter towards the second position. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0015]    The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
           [0016]      FIG. 1  is a side elevation view of a first example suspension system of the present invention shown on a bicycle frame; 
           [0017]      FIG. 2  is a close-up view of the first example suspension system with a seat tube cut-away; 
           [0018]      FIG. 3  is a close-up view of the first example suspension system with the seat tube, with an example first adapter therefor cut-away; 
           [0019]      FIG. 4  is a front elevation view depicting the first example suspension system and a first example mounting system for use therewith; 
           [0020]      FIG. 5  is a rear elevation view depicting the example first adapter for use with the first example suspension system; 
           [0021]      FIG. 6  is a close-up view of the first example suspension system in a first position with the seat tube, the example first adapter, and a portion of the suspension system cut-away; 
           [0022]      FIG. 7  is a close-up view similar to  FIG. 6  with the first example suspension system in a second position; 
           [0023]      FIG. 8  is a bottom plan view depicting the first example mounting system; 
           [0024]      FIG. 9  is a top plan view of the first example mounting system in a disassembled configuration; 
           [0025]      FIG. 10  is a top plan view of the first example mounting system in an assembled configuration; 
           [0026]      FIGS. 11-13  are side elevation views of the first example mounting system in a rearward position and in various angular positions; 
           [0027]      FIG. 14  is a side elevation view of the first example mounting system in a forward position and in a horizontal angular position; 
           [0028]      FIG. 15  is a side elevation view of a version of the first example mounting system used without a suspension system; 
           [0029]      FIG. 16  is a side elevation view of a second example suspension system of the present invention; 
           [0030]      FIG. 17  is a side elevation view of the second example suspension system with a first example mounting base; 
           [0031]      FIGS. 18 and 19  are side elevation views of the second example suspension system with a second example mounting base in first and second offset positions, respectively; 
           [0032]      FIG. 20  is a side elevation view of a third example suspension system of the present invention; 
           [0033]      FIG. 21  is a front elevation view depicting the third example suspension system and a second example mounting system for use therewith; 
           [0034]      FIG. 22  is a close-up view of the third example suspension system in a first position with the seat tube, the example first adapter, and a portion of the suspension system cut-away; 
           [0035]      FIG. 23  is a close-up view similar to  FIG. 22  with the third example suspension system in a second position; 
           [0036]      FIG. 24  is a side elevation view of a fourth example suspension system of the present invention; and 
           [0037]      FIG. 25  is a somewhat schematic, side elevation view of a fifth example suspension system of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0038]    The suspension system of the present invention may take a number of different forms, and a number of examples of the present invention will be discussed separately below. 
       1. First Example Suspension System 
       [0039]    Referring initially to  FIGS. 1-14  of the drawing, depicted therein is a first example suspension system  20  constructed in accordance with, and embodying, the principles of the present invention. As depicted in  FIG. 1 , the first example suspension system  20  will typically be used in combination with a bike  22  and a seat assembly  24 . The bike  22  and seat assembly  24  are not part of the present invention and will not be described herein beyond that extent necessary for a complete understanding of the present invention. The example bike  22  defines a seat tube  26  that defines a seat axis A, and the example seat assembly defines seat rails  28 . 
         [0040]    The suspension system  20  is used in combination with an example first adapter  30 , an example second adapter  32 , and a first example mounting system  34 . The first adapter  30  is configured operatively to connect the suspension system  20  to the seat tube  26 , and the second adapter  32  and mounting system  34  are configured operatively to connect the suspension system  20  the seat rails  28 . 
         [0041]    The first adapter  30  comprises a tube structure  40 , a base structure  42 , a first base pin  44 , a second base pin  46 , and a third base pin  48 . The tube structure  40  is adapted to be received by and secured to the seat tube  26  in a conventional manner. 
         [0042]    The base structure  42  defines a pair of base wall portions  50  and defines a base cavity  52 , a first base opening  54 , a pair of second base openings  56 , and a pair of third base openings  58 . In particular, the second base openings  56  are formed in the first and second wall portions  50   a  and  50   b  on either side of the base cavity  52 . The third base openings  58  are formed in the first and second wall portions  50   a  and  50   b  on either side of the base cavity  52  and below the second base openings  56 . The first base opening  54  is formed in a portion of the base structure  42  above the second base openings  56 . The first, second, and third base openings  54 ,  56 , and  58  are substantially arranged along a base line B that extends at an angle with respect to the seat axis A. 
         [0043]    The first adapter  30  is formed by extending the first base pin  44  through the first base opening  54  and such that ends of the pin  44  protrude on either side of the base structure  42 , the second base pin  46  through the second base openings  56  and across the base cavity  52  such that ends of the pin  46  protrude on either side of the base structure  42 , and the third base pin  48  through the third base openings  58  across the base cavity  52 . 
         [0044]    The second adapter  32  comprises a first adapter plate  60  and a second adapter plate  62 . The example adapter plates  60  and  62  are identical, and each defines first, second, third, and fourth adapter plate openings  70 ,  72 ,  74 , and  76 . The second adapter  32  further comprises first and second adapter plate pins  80  and  82  that extend through the first and second adapter plate openings  70  and  72 , respectively. First and second spacers  84  and  86  are arranged over the adapter plate pins  80  and  82  between the adapter plates  60  and  62 . The first and second adapter plate openings  70  and  72  are substantially arranged along and a first adapter axis C that extends at an angle with respect to the seat axis A and is substantially parallel to the base axis B. The third and fourth adapter plate openings  74  and  76  are substantially arranged along and a second adapter axis D that extends at an angle with respect to the first adapter axis C and is substantially horizontal during normal use of the bike  22  on level ground. 
         [0045]    The second adapter  32  further comprises first and second pivot bolt assemblies  90  and  92  that extend through the third and fourth adapter plate openings  74  and  76 , respectively, and engage the first example mounting system  34  as will be described in further detail below. 
         [0046]    The first example suspension system  20  comprises a linkage system  120  and a biasing system  122 . The biasing system  122  comprises upper and lower resilient systems  124  and  126 . The upper resilient system  124  defines an upper biasing axis E, and the lower resilient system  126  defines a lower biasing axis F. The example linkage system  120  comprises a pair of upper link plates  130  and a pair of lower link plates  132 . First, second, and third upper link plate openings  140 ,  142 , and  144  and one or more optional weight reduction openings  146  are formed in the upper link plates  130 . First, second, and third lower link plate openings  150 ,  152 , and  154  and one or more optional weight reduction openings  156  are formed in the lower link plates  132 . 
         [0047]    To form a parallel linkage that allows movement of the second adapter  32  relative to the first adapter  30 , the upper link plates  130  are connected between the first base pin  44  and the second adapter plate pin  82  and the lower link plates  132  are connected between the second base pin  46  and the first adapter plate pin  80 . In particular, the first base pin  44  extends through the first upper link plate openings  140 , the second base pin  46  extends through the first lower link openings  150 , the second adapter plate pin  82  extends through the second upper link plate openings  142 , and the first adapter plate pin  80  extends through the second lower link plate openings  152 . So assembled, the linkage system  120  defines an upper link axis G and a lower link axis H. 
         [0048]    The example upper resilient system  124  is a spring assembly comprising an upper spring  220 , an upper spring anchor  222 , an upper spring retainer assembly  224 , and an upper spring rod  226 . The upper spring retainer assembly  224  comprises an upper spring sleeve  230 , an upper spring collar  232 , an upper spring bumper  234 , and a pair of screws  236 . The upper spring anchor  222  defines a pivot portion  240 , a cylinder portion  242 , a stop surface  244 , a pivot opening  246 , and a guide cavity  248 . The upper spring sleeve  230  defines a rod opening  250  and end openings  252  adapted to threadingly receive the screws  236 . The upper spring collar  232  defines a flange portion  260 , a cylinder portion  262 , a stop surface  264 , a sleeve surface  266 , and a collar rod opening  268 . The upper spring bumper  234  defines a bumper surface  270  and a bumper rod opening  272 . 
         [0049]    The example lower resilient system  126  is a spring assembly comprising a lower spring  320 , a lower spring anchor  322 , a lower spring retainer assembly  324 , and a lower spring bolt  326 . The lower spring retainer assembly  324  comprises a lower spring sleeve  330 , a lower spring collar  332 , a lower spring bottom out bumper  334 , a pair of screws  336 , and a lower spring top out bumper  338 . The lower spring anchor  322  defines a pivot portion  340 , a cylinder portion  342 , a stop surface  344 , a pivot opening  346 , and a bolt cavity  348 . The lower spring sleeve  330  defines a bolt opening  350  and end openings  352  adapted to receive the screws  336 . The lower spring collar  332  defines a flange portion  360 , a cylinder portion  362 , a stop surface  364 , a sleeve surface  366 , and a collar bolt opening  368 . The lower spring bottom out bumper  334  defines a bottom out bumper surface  370  and a bumper bolt opening  372 . The lower spring top out bumper  338  defines a top out bumper bolt opening  380 , and the lower spring bolt  326  defines a head  390  and a shaft  392  having a threaded portion  394 . The bolt cavity  348  is threaded to receive the threaded portion  394  of the shaft  392 . 
         [0050]    To assemble the biasing system  122 , the second and third base pins  46  and  48  are extended through the pivot openings  246  and  346  of the spring anchors  222  and  322 , respectively. 
         [0051]    The upper spring  220  is next arranged over the cylinder portion  242  and against the stop surface  244  of the upper spring anchor  222 . A first end of the upper spring rod  226  is then passed through the bumper rod opening  272  and the collar rod opening  268  and inserted into the guide cavity  248 . A second end of the upper spring rod  226  is inserted through the sleeve rod opening  250  and into guide cavity  248 , and the screws  236  are passed through the third upper link plate openings  144  and threaded into the end openings  252  of the sleeve  230  to secure the sleeve  230  to the upper link plates  130 . 
         [0052]    The lower spring  320  is next arranged over the cylinder portion  342  and against the stop surface  344  of the lower spring anchor  322 . The threaded portion  394  of the lower spring bolt  326  is then passed through the top out bumper bolt opening  380 , the sleeve bolt opening  350 , the bottom out bumper rod bolt opening  372 , and the collar rod bolt opening  368  and threaded into the bolt cavity  348 . The screws  336  are passed through the third lower link plate openings  154  and threaded into the end openings  352  of the sleeve  330  to secure the sleeve  330  to the lower link plates  132 . 
         [0053]    So assembled, the linkage system  120  allows movement of the second adapter  32  along a limited arc relative to the first adapter  30  between a first position (e.g.,  FIG. 6 ) and a second position through a continuum of intermediate positions (e.g.,  FIG. 7 ). The first position is defined as the uppermost position of the second adapter  32  relative to the first adapter  30  allowed by the linkage system  120  and the spring system  122 . The second position is defined as the lower position of the second adapter  32  relative to the first adapter  30  allowed by the linkage system  120  and the spring system  122 . 
         [0054]    In the first position as shown in  FIG. 6 , the lower spring sleeve  330  is substantially arranged along the first adapter axis C. As the linkage system  120  moves from the first position towards the second position, the lower spring sleeve  330  is displaced towards the lower spring anchor  322  and becomes offset from the first adapter axis C. The lower spring bumper  334  engages the cylinder portion  342  of the lower spring anchor  322  when the second adapter  32  reaches the second position. The location of the second adapter  32  relative to the first adapter  30  in the second position can be altered by altering a size of the lower spring bottom out bumper  334 . 
         [0055]    Additionally, the upper biasing axis E defined by the upper resilient system  124  extends at a primary spring angle relative to the lower biasing axis F defined by the lower resilient system  126 . In the example suspension system  20 , in the first position this primary spring angle is approximately 19 degrees, may be within a first range of approximately 17 to 20 degrees, and in any event should be within a second range of approximately 15 to 21 degrees. The upper and lower link axes G and H are substantially parallel to each other. 
         [0056]    In the example suspension system  20 , the upper biasing axis E extends at a first secondary spring angle with respect to the link axes G and H. The lower biasing axis F extends at a second secondary spring angle with respect to the link axes G and H. In the first position, the first secondary spring angle is approximately 18 degrees, may be within a first range of approximately 19 to 20 degrees, and in any event should be within a second range of approximately 17 to 21 degrees. In the first position, the second secondary spring angle is approximately 4 degrees, may be within a first range of approximately 3 to 6 degrees, and in any event should be within a second range of approximately 2 to 10 degrees. 
         [0057]    The primary spring angle will increase slightly as the linkage system  120  moves out of the first position towards the second position as will become apparent from the following detailed discussion. 
         [0058]    The biasing system  122  biases the second adapter  32  into the first or upper (during normal use of the bike  22 ) position relative to the first adapter  30  and thus relative to the bike  22 . However, a rider sitting on the seat  24  will cause a slight downward movement of the second adapter  30  out of the first position and towards the second position. 
         [0059]    Accordingly, as the bike  22  is traveling along an uneven surface, the bike  22  will tend to move up and down relative to a rider on the seat  24 . This up and down movement of the bike  22  relative to the seat  24  causes shocks that are resiliently opposed by the biasing system  122 . The biasing system  122  thus resiliently opposes movement of the linkage system  120  such that upward movement bike  22  relative to the seat  24  is controlled. 
         [0060]    The transmissibility and over all spring rate of the biasing system  122  can be altered by selecting combinations of lengths and spring rates of the upper and lower springs  220  and  320  that are suitable for a particular bike setup, rider weight, and terrain conditions. 
         [0061]    Further, axial rotation of the lower spring bolt  326  causes the bolt head  390  to act on the lower spring sleeve  330  through the lower spring washer  338  to pre-compress the biasing system  122 . The lower spring bolt  326  thus forms an adjustment system that allows a pre-load force to be applied on the lower spring  320  that alters the characteristics of the suspension system  20 . The lower spring bolt  325  may be replaced by a spring rod similar to the upper spring rod  226  if adjustability of the suspension system  520  is not required. 
         [0062]    The top out bumper is thus adjustable by turning the lower spring bolt  326  and the bottom out bumper is adjustable by inserting different length and durometer elastomers as the bottom out bumper member  334 . Controlling or constraining the available travel of the second adapter  32  relative to the first adapter  34  is a way of limiting the amplification of the road induced vibrations at low frequencies. Accordingly, the shock transmitted to the rider is minimized by minimizing the damping or friction in the system at higher frequencies, where amplification of road induced vibrations is not an issue. 
         [0063]    The following Table A sets forth a number of example dimensions depicted in  FIG. 2  related to the geometry of the example linkage system  120  of the first example suspension system  20 : 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE A 
               
               
                   
               
               
                 Dimension 
                 Example 
                 First Range 
                 Second Range 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 L1 
                 2.3 
                 in 
                 1.8-2.8 
                 in 
                 1.0-4.0 
                 in 
               
               
                 L2 
                 2.3 
                 in 
                 1.8-2.8 
                 in 
                 1.0-4.0 
                 in 
               
               
                 L3 
                 .8 
                 in 
                 .7-1.0 
                 in 
                 .7-1.5 
                 in 
               
               
                 L4 
                 .6 
                 in 
                 .6-.8 
                 in 
                 .6-1.0 
                 in 
               
               
                 L5 
                 .8 
                 in 
                 .7-1.0 
                 in 
                 .7-1.5 
                 in 
               
               
                 L6 
                 .8 
                 in 
                 .7-1.0 
                 in 
                 .7-1.5 
                 in 
               
               
                 L7 
                 .6 
                 in 
                 .5-.7 
                 in 
                 .5-.8 
                 in 
               
             
          
           
               
                 L8 
                 first position 
                 2.2 
                 in 
                 1.8-2.8 
                 in 
                 .75-3.8 
                 in 
               
               
                   
                 second position 
                 1.8 
                 in 
                 1.5-2.3 
                 in 
                 0.5-3.4 
                 in 
               
               
                 L9 
                 first position 
                 2.5 
                 in 
                 2.0-3.0 
                 in 
                 1.0-4.2 
                 in 
               
               
                   
                 second position 
                 2.0 
                 in 
                 1.8-2.5 
                 in 
                 0.7-3.8 
                 in 
               
               
                   
               
             
          
         
       
     
         [0064]    The following Table B sets forth a number of example parameters associated with the example biasing system  122  of the first example suspension system  20 . Typically, a plurality of the springs  220  and  320  (A, B, C, D, and E in Table B) will be provided for each of the upper resilient system  124  and the lower resilient system  126 . Each of the plurality of springs  220  and  320  provided for each of the resilient systems  124  and  126  exhibit different transmissibilities. Typically, one of the springs  220  and one of the springs  320  will be selected for each of the upper spring and the lower spring assemblies  124  and  126 , respectively: 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
               
             
           
               
                 TABLE B 
               
               
                   
               
               
                 Dimension 
                 Example 
                 First Range 
                 Second Range 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Upper Free 
                 1.75 
                 in 
                 1.25-2.25 
                 in 
                 1-3.5 
                 in 
               
               
                 Spring Length 
               
             
          
           
               
                 Upper Spring 
                 A 
                 100 
                 lb/in 
                 100-700 
                 lb/in 
                 100-700 
                 lb/in 
               
               
                 Rate 
                 B 
                 181 
                 lb/in 
               
               
                   
                 C 
                 288 
                 lb/in 
               
               
                   
                 D 
                 500 
                 lb/in 
               
               
                   
                 E 
                 680 
                 lb/in 
               
             
          
           
               
                 Lower Spring 
                 2.0 
                 in 
                 1.5-2.5 
                 in 
                 1-4 
                 in 
               
               
                 Length 
               
             
          
           
               
                 Lower Free 
                 A 
                 90 
                 lb/in 
                 90-600 
                 lb/in 
                 90-600 
                 lb/in 
               
               
                 Spring Rate 
                 B 
                 162 
                 lb/in 
               
               
                   
                 C 
                 248 
                 lb/in 
               
               
                   
                 D 
                 425 
                 lb/in 
               
               
                   
                 E 
                 585 
                 lb/in 
               
               
                   
               
             
          
         
       
     
         [0065]    Turning now to  FIGS. 4 ,  5 , and  8 - 14 , the example mounting system  34  will now be described in further detail. 
         [0066]    The example mounting system  34  comprises a base member  420 , a pair of clamp members  422 , and a pair of clamp screws  424 . The base member  420  defines a support plate  430  and a pivot flange  432 . The pivot plate  432  extends downwardly from a bottom surface of the support plate  430 . Clamp openings  434  and a clamp groove  436  are formed in the support plate  430 , and pivot openings  438  are formed in the pivot flange  432 . A screw opening  440 , a second clamp groove  442 , and a clamp surface  444  are formed in each of the clamp members  422 . In the example mounting system  34 , the clamp openings  434  are angled towards each other as shown in  FIG. 4  to facilitate access to the clamp screws  424  when the clamp screws  424  are connected to the clamp members  422  through the clamp openings  434 . 
         [0067]    The clamp screws  424  are threaded into one of the clamp openings  434  and the screw openings  440  to secure the clamp members  422  to the base member  420  as generally shown in  FIGS. 8-10 . The seat rails  28  are arranged to be received by the first and second clamp grooves  436  and  442  to securely clamp the rails  28  in a desired position relative to the base member  420  when the clamp screws  424  are tightened. The clamp surfaces  444  engage the upper surface of the support plate to enhance the clamping forces applied to the rails  28 . 
         [0068]    The pivot openings  438  take the form of elongate, arcuate openings that are sized, dimensioned, and located and oriented relative to each other to receive the first and second pivot bolt assemblies  90  and  92  of the second adapter  32  described above. The pivot openings  438  receive the pivot bolt assemblies to allow pivoting movement of the base member  420  relative to the first and second adapter plates  60  and  62  as shown in  FIGS. 11-13 . In addition, the example support plate  430  is offset from the pivot flange  432  such that the base member may be supported in a rear position as depicted in  FIG. 11  or in a forward position as depicted in  FIG. 14 . In the forward position, the can also be pivoted in a manner similar to that depicted in  FIGS. 12 and 13 . 
         [0069]      FIG. 15  illustrates that the example mounting system  34  can be used without the suspension system  20 . In particular, an adapter plate assembly  460  defining a first wall  462 , a second wall  464 , and a tube portion  466  is provided. The tube portion  466  engages the seat tube  26  in a conventional manner. The first and second walls  462  and  464  each define first and second wall openings  470  and  472  that receive bolt assemblies  480  and  482 . The bolt assemblies  480  and  482  extend through the pivot openings  438  of the base member  420  to allow pivoting movement of the base member  420  relative to the adapter plate assembly  460  as generally described above with respect to the example suspension system  20 . 
       2. Second Example Suspension System 
       [0070]    Referring now to  FIGS. 16-17  of the drawing, depicted therein is a second example suspension system  520  constructed in accordance with, and embodying, the principles of the present invention. As depicted in  FIG. 1 , the second example suspension system  520  will typically be used in combination with a bike  522  and a handle bar assembly  524 . The bike  522  and handle bar assembly  524  are not part of the present invention and will not be described herein beyond that extent necessary for a complete understanding of the present invention. The example bike  522  defines a steerer  526  that defines a steering axis J. 
         [0071]    The suspension system  520  is used in combination with an example first adapter  530 , an example second adapter  532 , and a second example mounting system  534 . The first adapter  530  is configured operatively to connect the suspension system  520  to the steerer  526 , and the second adapter  532  and mounting system  534  are configured operatively to connect the suspension system  520  the handle bar assembly  524 . 
         [0072]    The first adapter  530  comprises a clamp portion  540 , a base portion  542 , and first, second, and third base pins  544 ,  546 , and  548 . The clamp portion  540  is adapted to engage the steerer  526  in a conventional manner. The base portion  542  defines base wall portions  550  between which a base cavity  552  is defined. First, second, and third base openings  554 ,  556 , and  558  are formed in each of the base wall portions  550  and receive the first, second, and third base pins  544 ,  546 , and  548 , respectively. 
         [0073]    As shown in  FIGS. 16 and 17 , the second adapter  532  comprises an adapter mount  560  connected to a pair of adapter plates  562  and first, second, and third adapter pins  564 ,  566 , and  568  extending between the adapter plates  562 . The example second adapter  532  further comprises a mounting base  570 , a clamp fixture  572 , a clamp member  574 , and bolt assemblies  576 . The bolt assemblies  576  secure the mounting base  570  to the adapter mount  560 , the clamp fixture  572  to the mounting base  570 , and the clamp member  574  to the clamp fixture  572 . The handle bar  528  is gripped between the clamp fixture  572  and the clamp member  574  to secure the handle bar  528  relative to the second adapter  532 . The mounting base  570  determines a spacing of the handle bar  528  relative to the steering axis J. In  FIG. 16 , the mounting base  574  is omitted to fit the profile of a first rider, while in  FIG. 17  the mounting base  574  is used to space the handle bar  528  further from the second adapter  532  to fit the profile of a second rider. 
         [0074]    Alternatively, as shown in  FIGS. 18 and 19  the second adapter  532  may comprise, in addition to the adapter mount  560 , the pair of adapter plates  562 , and the first, second, and third adapter pins  564 ,  566 , and  568 , a mounting base  580 , a clamp fixture  582 , a clamp member  584 , a first set of bolt assemblies  586 , and a second set of bolt assemblies  588 . The first set of bolt assemblies  586  the mounting base  580  to adapter mount  560 . The second set of bolt assemblies  588  attach the clamp member  584  to the clamp fixture  582  and the clamp fixture  582  to the mounting base  580 . Again, the handle bar  528  is gripped between the clamp fixture  582  and the clamp member  584  to secure the handle bar  528  relative to the second adapter  532 . The mounting base  580  determines a spacing of the handle bar  528  relative to the steering axis J, and the mounting base may be rotated as shown by a comparison of  FIGS. 18 and 19  to be in a lower position ( FIG. 18 ) or an upper position ( FIG. 19 ) relative to the adapter mount  560 . 
         [0075]    The second example suspension system  520  comprises a linkage system  590  and a biasing system  592  similar to the linkage system  120  and biasing system  122  described above, and the linkage system  590  and biasing system  592  of the second example suspension system  520  will not be described again in detail herein. As with the first example suspension system  20 , when the second example bike  522  travels along an uneven surface, the bike  522  will tend to move up and down relative to a rider grasping the handle bar assembly  524 . This up and down movement of the bike  522  relative to the handle bar assembly  524  results in shocks that are resiliently opposed by the second suspension system  520  in a manner similar to that of the first example suspension system  20  described above. In particular, upward movement bike  522  relative to the handle bar assembly  524  is limited, thereby reducing shocks on a rider grasping the handle bar assembly  524 . 
         [0076]    The example biasing system  592  may be provided with an adjustment bolt such as the example bolt  326  described above, or the adjustment bolt may be omitted if adjustability of the suspension system  520  is not required. 
         [0077]    Given that the amount of the rider&#39;s weight borne by the handle bar assembly  524  will typically be less than that borne by a seat, the dimensions of the linkage system  590  and the biasing system  592  and the transmissibility of the springs of the biasing system  592  may be altered accordingly. 
       3. Third Example Suspension System 
       [0078]    Referring now to  FIGS. 20-23  of the drawing, depicted therein is a third example suspension system  620  constructed in accordance with, and embodying, the principles of the present invention. As depicted in  FIG. 20 , the third example suspension system  620  will typically be used in combination with a bike (not shown) and a seat assembly (not shown). The bike and seat assembly are not part of the present invention and will not be described herein beyond that extent necessary for a complete understanding of the present invention. As is conventional, the bike will define a seat tube  626  that defines a seat axis A, and the seat assembly defines seat rails  628 . 
         [0079]    The suspension system  620  is used in combination with an example first adapter  630 , an example second adapter  632 , and a third example mounting system  634 . The first adapter  630  is configured operatively to connect the suspension system  620  to the seat tube  626 , and the second adapter  632  and mounting system  634  are configured operatively to connect the suspension system  620  the seat rails  628 . The mounting system  634  is or may be conventional and will not be described herein in further detail. 
         [0080]    The first adapter  630  comprises a tube structure  640 , a base structure  642 , a first base pin  644 , and a second base pin  646 . The tube structure  640  is adapted to be received by and secured to the seat tube  626  in a conventional manner. 
         [0081]    The base structure  642  defines a first bearing surface  650 , a second bearing surface  652 , a first base opening  654 , and a second base opening  656 . The example first and second bearing surfaces  650  and  652  are arcuate surfaces, and the first bearing surface  650  is substantially coaxially aligned with the second opening  646 . The first base openings  654  are formed above the second base openings  656 , and the second base openings  656  are formed above the second bearing surface  650 . The longitudinal axes of the first and second base openings  654  and  656  and the axis of the second bearing surface  62  are substantially evenly spaced along a base line B that extends at an angle with respect to the seat axis A. 
         [0082]    The first adapter  630  is formed by extending the first base pin  644  through the first base opening  654  and such that ends of the first base pin  644  protrude on either side of the base structure  642  and the second base pin  646  through the second base openings  656  and across the base cavity  652  such that ends of the pin  646  protrude on either side of the base structure  642 . 
         [0083]    The second adapter  632  comprises an adapter plate  660 . The example adapter plate  660  defines first, second, and third adapter plate openings  670 ,  672 , and  674 . The second adapter  632  further comprises first and second adapter plate pins  680  and  682  that extend through the first and second adapter plate openings  670  and  672 , respectively, and protrude on either side of the adapter plate  660 . The first and second adapter plate openings  670  and  672  are substantially arranged along a first adapter axis C that extends at an angle with respect to the seat axis A and is substantially parallel to the base axis B. 
         [0084]    The third example suspension system  620  comprises a linkage system  720 , a biasing system  722 , and a set screw  724 . 
         [0085]    The biasing system  722  comprises upper and lower biasing systems  730  and  732 . The upper resilient system  730  defines an upper biasing axis E, and the lower resilient system  732  defines a lower biasing axis F. 
         [0086]    The example linkage system  720  comprises a pair of upper link plates  740 , a pair of lower link plates  742 , a connector bolt  744 , and a spacer  746 . First, second, third, and fourth upper link plate openings  750 ,  752 ,  754 , and  756  are formed in the upper link plates  740 . First, second, and third lower link plate openings  760 ,  762 , and  764  are formed in the lower link plates  742 . 
         [0087]    The example upper resilient system  730  is a spring assembly comprising an upper spring  820 , an upper spring anchor  822 , an upper spring retainer assembly  824 , and an upper spring rod  826 . The upper spring sleeve retainer assembly  824  comprises an upper spring sleeve  830 , an upper spring collar  832 , and an upper spring bolt assembly  834 . The example lower resilient system  724  is a spring assembly comprising a lower spring  920 , a lower spring anchor  922 , a lower spring retainer assembly  924 , and a lower spring rod  926 . The lower spring sleeve retainer assembly  924  comprises a lower spring sleeve  930 , a lower spring collar  932 , and a lower spring bolt assembly  934 . 
         [0088]    To form a parallel linkage that allows movement of the second adapter  632  relative to the first adapter  630 , the upper link plates  740  are connected between the first base pin  644  and the second adapter plate pin  682  and the lower link plates  742  are connected between the second base pin  646  and the first adapter plate pin  680 . In particular, the first base pin  644  extends through the first upper link plate openings  750 , the second base pin  646  extends through the first lower link openings  760 , the second adapter plate pin  682  extends through the second upper link plate openings  752 , and the first adapter plate pin  680  extends through the second lower link plate openings  762 . 
         [0089]    In addition, the connector bolt  744  is connected between the fourth upper link plate openings  756  to hold the upper link plates  740  in place to form part of the parallel linkage. The spacer  746  is arranged over connector bolt  744  to maintain the upper link plates  740  in a substantially parallel configuration. The upper spring bolt assembly  834  extends between the third upper link plate openings  754  and through upper spring retainer assembly  824  to secure the upper link plates  740  in the parallel linkage and to retain the upper resilient system  730  in its assembled configuration. Similarly, the lower spring bolt assembly  934  extends between the third lower link plate openings  854  and through the lower spring retainer assembly  924  to secure the lower link plates  842  in the parallel linkage and to retain the lower resilient system  732  in its assembled configuration. 
         [0090]    The upper spring anchor  822  is rotatably supported by the base structure  642  against the first bearing surface  650 . The upper spring sleeve  830  is attached relative to the upper link plates  740  by the upper spring bolt assembly  834 . The upper spring  820  and upper spring rod  826  are held between the upper spring anchor  822  and the upper spring collar  832  by the upper spring sleeve  830 . Similarly, the lower spring anchor  922  is supported against the second bearing surface  652  of the base structure  642 . The lower spring sleeve  930  is supported relative to the lower link plates  742  by the lower spring bolt assembly  934 . The lower spring  920  and lower spring rod  926  are held between the lower spring anchor  922  and the lower spring sleeve  930 . 
         [0091]    When assembled, the linkage system  720  allows movement of the second adapter  632  along a limited arc relative to the first adapter  630  between a first position and a second position through a continuum of intermediate positions. In the first position, the lower spring sleeve  930  is substantially arranged along the first adapter axis C. As the linkage system  720  moves from the first position towards the second position, the upper and lower spring sleeves  830  and  930  are displaced towards the upper and lower spring anchors  822  and  922 , thereby compressing the upper and lower springs  820  and  920 . 
         [0092]    Additionally, the upper biasing axis E defined by the upper resilient system  730  is substantially parallel to the lower biasing axis F defined by the lower resilient system  732 . The biasing axes E and F, however, extend a spring angle with respect to the link axes G and H. In the example suspension system  620 , in the first position the spring angle is approximately 14 degrees, may be within a first range of approximately 12 to 16 degrees, and in any event should be within a second range of approximately 10 to 18 degrees. The spring angle will increase slightly as the linkage system moves out of the first position towards the second position. 
         [0093]    The biasing system  722  thus biases the second adapter  632  into the first or upper (during normal use of the bike) position relative to the first adapter  630  and thus relative to the bike  622 . However, as shown in  FIG. 23 , a rider sitting on the bicycle seat will cause a slight downward movement of the second adapter  632  out of the first position and towards the second position. 
         [0094]    Accordingly, as the bike is traveling along an uneven surface, the bike  622  will tend to move up and down relative to a rider on the seat  624 . This up and down movement of the bike relative to the seat causes shocks that are resiliently opposed by the biasing system  722 . The biasing system  722  thus resiliently opposes movement of the linkage system  720  such that upward movement bike relative to the seat is limited, thereby reducing shocks on a rider sitting on the seat. 
         [0095]    The set screw  724  is configured to engage the upper spring sleeve  830  to displace the linkage system  720  away from its first position to pre-compress the suspension system  620  in a manner generally similar that of the lower spring bolt  326  described above. Again, the set screw  724  is optional and need not be used if pre-compression of the suspension system  620  is not required. 
         [0096]    Turning now to  FIG. 24  of the drawing, depicted therein is a fourth example suspension system  1020  constructed in accordance with, and embodying, the principles of the present invention. The fourth example suspension system  1020  is used in combination with an example first adapter  1030 , an example second adapter  1032 , and a first example mounting system (not shown). The fourth example suspension system  1020  comprises a link system  1040  and a biasing system  1042 . The example link system  1040  comprises pairs of upper and lower link plates  1050  and  1052 , and the example biasing system  1042  comprises an upper spring assembly  1060  and a lower spring assembly  1062 . The example suspension system  1020  is in most respects similar to the first example suspension system  20  describe above, but the upper spring assembly  1060  is arranged between the pairs of upper and lower link plates  1050  and  1052 , while the lower spring assembly  1062  is arranged below the pair of lower link plates  1052 . 
         [0097]    Turning now to  FIG. 25  of the drawing, depicted therein is a fifth example suspension system  1120  constructed in accordance with, and embodying, the principles of the present invention. The fifth example suspension system  1120  is used in combination with an example first adapter  1130 , an example second adapter  1132 , and a first example mounting system (not shown). The fifth example suspension system  1120  comprises a link system  1140  and a biasing system  1142 . The example link system  1140  comprises pairs of upper and lower link plates  1150  and  1152 , and the example biasing system  1142  comprises an upper gas cylinder assembly  1160 , a lower gas cylinder assembly  1162 , and a reservoir  1164  operatively connected to the gas cylinder assemblies  1160  and  1162 . The example suspension system  1120  is in most respects similar to the fourth example suspension system  1020  described above, but the gas cylinders are used instead of spring assemblies. 
         [0098]    From the foregoing, it should be apparent that the present invention in its broadest form may be embodied in a number of forms, the foregoing of which are several examples. The scope of the invention should thus be determined by the claims appended hereto and not the foregoing detailed description of the example embodiments. 
         [0099]    While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.