CROSS-REFERENCE TO RELATED APPLICATIONS 
     This continuation-in-part application claims the benefit of U.S. patent application Ser. No. 09/803,911 filed Mar. 13, 2001, abandoned Feb. 6, 2002; which is a division of U.S. patent application Ser. No. 09/433,711 filed Nov. 4, 1999, abandoned May 13, 2001; which application claims the benefit of U.S. Provisional Patent Application Serial No. 60/110,481, filed Dec. 1, 1998. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to sprint vehicle suspension systems incorporating an air bag in lieu of springs, torsion bars or a coil-over design. This application further modifies the aforementioned structural systems by having (1) the front axle supporting a pair of air bags mounted proximate each front wheel, and (2) the rear axle having bird cages mounted adjacent each rear wheel over the wheel bearings and the air bags mounted on extensions. 
     2. Description of the Related Art 
     Sprint cars and other open wheeled race cars typically use a swing arm suspension. A representative prior art view is shown in FIG. 3 of this application, wherein a rear axle  180  of a sprint car  18  has a carrier hub  310  connecting the suspension to the wheel. One end of the swing arms  140  and  350  is attached to a torsion bar  320 , and the other end is attached to a means of supporting a wheel, such as a carrier hub  310  on a live axle or the axle itself on a fixed axle. The torsion bar  320  is typically housed within a tubing in the frame  330  shown in shadow. The carrier hub  310  is attached to a swing arm  140  which is connected to a torsion bar  320 . If only one swing arm is utilized, the swing arm  140  may lead or trail its associated axle. Supplemental suspension linkages may be present for additional support to the axle  180 . 
     Exemplary patents of various suspension systems include the following patents and patent application publications. 
     U.S. Pat. No. 2,453,388 issued on Nov. 9, 1948, to Arthur G. Schramm describing a wheel suspension for trailers comprising wheels suspended on arms controlled by levers sprung to provide resiliency, and the arms being arcuately adjustable. 
     U.S. Pat. No. 3,063,733 issued on Nov. 13, 1962, to Bryan J. Morris describes an anti-roll vehicle suspension mechanism comprising a pair of cylindrical springs, a pair of levers pivotally connected to the chassis, axle and the springs. 
     U.S. Pat. No. 3,410,573 issued on Nov. 12, 1968, to Albert F. Hickman describes a vehicle spring suspension comprising an axle supporting a first arm fixed to a hub member or cross shaft. A second arm fixed to and projects radially from the hub member to bear compressively against a rubber body connected to the vehicle frame. 
     U.S. Pat. No. 3,822,908 issued on Jul. 9, 1974, to Rene Gouirand describing a suspension system using single or dual air bags having a tapered cross-section in the truck&#39;s longitudinal direction and supported by an upper plate and a pair of lower lever members or axle supports. The air bags are pressurized by an air pump. 
     U.S. Pat. No. 3,964,764 issued on Jun. 22, 1976, to Erik G. Rickardsson describes an air spring axle assembly for a spring suspension and sway resistance of a vehicle chassis comprising a U-shaped frame as a box girder spring-mounted and supporting a wheel axle. 
     U.S. Pat. No. 4,415,179 issued on Nov. 15, 1983, to Joseph A. Marinelli describes an axle and air bag suspension comprising a forward mounting portion and a front-to-rear trailing arm which has its forward end pivotally supported. The rear end portion of the arm is anchored to an axle by a bushed clamp sleeve. An air bag is mounted on a stationary mount portion. A Y-shaped stabilizer bar has its free ends pivoting from the forward chassis mount. 
     U.S. Pat. No. 4,418,932 issued on Dec. 6, 1983, to Paul W. Claar describes a front axle suspension system for a vehicle chassis comprising a first forward link and a second rearward link pivotally connected and extending down from the chassis and coupled to a third link. A spring and dampener mechanism interconnects the coupler link and chassis. 
     U.S. Pat. No. 4,733,876 issued on Mar. 29, 1988, to Merle J. Heider et al. describes a leaf spring supplemented with a pressure controllable air bag supplying variable spring adjustment, variable ride height, and stationary levelling of a motor home. 
     U.S. Pat. No. 4,842,297 issued on Jun. 27, 1989, to Mitsuo Takahashi describes a wishbone suspension system comprising upper and lower suspension arms with each arm having one end pin-connected to the vehicle body, and a knuckle member connected to a wheel axle. A connecting rod is connected at one end to an intermediate portion of one of the suspension arms, and a bell crank lever having a first end pin-connected to the other end. A second end pin is connected to one end of the knuckle member and a bent portion between these first and second ends. The bent portion is pin-connected to the other end of the suspension arms. 
     U.S. Pat. No. 4,858,210 issued on Aug. 22, 1989, to Donovan B. Wallace et al. describes a trailing arm suspension with a fixed cup communicating with a movable piston air spring mounted by a clamp in lateral juxtaposed relationship to a terminal end of the trailing arm assembly. A track bar with bushed joints at both ends interconnects the frame and the axle housing to provide lateral stability. 
     U.S. Pat. No. 4,923,210 issued on May 8, 1990, to Merle J. Heider et al. describes a leaf spring in conjunction with an air bag for motorhome levelling. A pneumatic control system communicates with the air bag to control the bag pressure. 
     U.S. Pat. No. 5,083,812 issued on Jan. 28, 1992, to Donovan B. Wallace et al. describes an air spring suspension system including trailing arms connecting the vehicle frame to a transverse beam connecting them with bushed articulating joints which permit the trailing arms to move with respect to each other. A stiffener arm is mounted at one end to each trailing arm by a bushed connection, and rigidly secured at the other end to the transverse beam. The system resists roll forces. 
     U.S. Pat. No. 5,265,907 issued on Nov. 30, 1993, to Ray Tostado describes a bolt on an auxiliary air bag suspension system, wherein the frame takes existing apertures provided in certain trucks, resulting in a removable supplemental suspension system that assists the factory suspension system. 
     U.S. Pat. No. 5,346,246 issued on Sep. 13, 1994, to Cecil Lander et al. describes an air bag suspension system controller for adjustment of spring rates of an air bag coupled in parallel with a leaf spring. 
     U.S. Pat. No. 5,366,238 issued on Nov. 22, 1994, to Donald L. Stephens describes a trailing arm suspension system having a tapered arm at a pivoting end so as to reduce arm weight in conjunction with an air spring at the opposite end. 
     U.S. Pat. No. 5,375,871 issued on Dec. 27, 1994, to James L. Mitchell et al. describes a vehicle suspension system comprising a wide base beam and an axle shell. The beam is mounted for pivoting movement to a hanger and securely to a vehicle axle. The beam is constructed with a laterally widening base as it extends longitudinally from the pivot mounting to the axle, and with an axle shell securing the beam to the axle to reduce stress on the axle. 
     U.S. Pat. No. 5,431,429 issued on Jul. 11, 1995, to Unkoo Lee describes a vehicle suspension system including a knuckle pivotally supporting a wheel with upper and lower control arms connecting upper and lower parts of the knuckle to the vehicle. 
     U.S. Pat. No. 5,584,497 issued on Dec. 17, 1996, to Cecil Lander et al. describes an air bag suspension controller system for automatic adjustment of spring rates of an air bag mechanically coupled in parallel with a leaf spring. 
     U.S. Pat. No. 5,639,110 issued on Jun. 17, 1997, to William C. Pierce et al. describes a trailing arm suspension for heavy duty vehicles comprising a fabricated beam of three pieces connected at two joints. A shock absorber bracket is integrally formed with the basic beam. A casting fixed in a preformed seat in the basic beam facilitates an axle connection. 
     U.S. Pat. No. 5,649,719 issued on Jul. 22, 1997, to Gareth A. Wallace et al. describes a weight-reducing, z-spring alternative in the form of an arm linkage and suspension system for heavy weight bearing vehicles featuring upper arms y-mounted to the frame sides and the axle center. 
     U.S. Pat. No. 5,711,544 issued on Jan. 27, 1998, to Reinhard Buhl describes an axle suspension for rigid vehicle axles comprising two longitudinal control arms connecting the vehicle body to the axle. A triangle pull rod is articulated to the axle and body centrally, and laterally offset. A stabilizer bar including a torsion spring bar counteracts lateral tilting by torsional stresses. The stabilizer bar is arranged directly between the longitudinal control arms, and its ends connected as a universal joint, but rotating in unison. 
     U.S. Pat. No. 5,765,859 issued on Jun. 16, 1998, to Corbett W. Nowell et al. describes a modular squatdown wheeled suspension system comprising air bags supported between pivoted bracket elements located adjacent the trailer wheels. An air supply system with an automatic locking arrangement allows the trailer deck to be lowered to a ground engaging position and raised back to the transport position. 
     U.S. Pat. No. 5,908,198, issued on Jun. 1, 1999, to Ervin K. VanDenberg describes a center beam and air spring suspension system comprising a central beam having a mounting flange on each side and pivotally mounted to a suspension frame at one end and rigidly attached to an axle at the other end. A control arm is pivotally mounted to each mounting flange at one end, and to the suspension frame at the other end. The pivot connection of the central beam may have a constant or varying air spring rate. 
     U.S. Pat. No. 5,988,672 issued on Nov. 23, 1999, to Ervin K. VanDenberg describes an air spring suspension system with an integral box beam comprising the box beam welded around the axle and having a pair of axially aligned and spaced apart pivots which include air springs having horizontal, vertical and axial spring rates. 
     U.S. Pat. No. 6,039,337 issued on Mar. 21, 2000, to Brian A. Urbach describes a vehicle suspension with a stroke-reducing linkage comprising a spring/damper assembly interposed between the control arm and the vehicle frame. 
     U.S. Pat. No. 6,070,861 issued on Jun. 6, 2000, to Jack D. Ecktman describes a bumper extension for use with a bumper on an air spring. 
     U.S. Pat. No. 6,089,583 issued on Jul. 18, 2000, to Erkki Taipale describes a vehicle stabilizer incorporating a torsion bar. 
     U.S. Pat. No. 6,092,614 issued on Jul. 25, 2000, to Tae-Hak Shin describes a structure for installing a conventional shock absorber for the rear suspension in a solar driven automobile. 
     U.S. Pat. No. 6,203,039 B1 issued on Mar. 20, 2001, to Marvin J. Gordon describes an independent suspension system for a four-wheeled trailer with an improved vertical alignment and range of travel which includes air bags at each end of the axle beams. 
     Canadian Patent Application No. 492,516 published on May 5, 1953, for Ernest E. Smith et al. describes a suspension system with an inelastic yet flexible inflatable conduit providing an air cushion. 
     Netherlands Patent Application No. 7612-924 published on May 23, 1978, for Dr. S. Rosenthal describes a swing arm suspension system having an air spring with the wheel situated at a fulcral point. The air spring may have an auxiliary spring of the diabolo type inside. 
     German Patent Application No. 3934-238-A1 published on Apr. 18, 1991, for Audi AG (Heinz Hollerweger et al.) describes a vehicle wheel suspension with an elastically mounted wheel guide and having a first variable volume chamber acted on by lateral wheel forces to create an under-steer effect on the wheel. The first chamber is pressurized by a second variable volume chamber operated by lateral wheel forces. The two chambers can be incorporated into one unit with no separate components required. 
     None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, an air bag for sprint cars solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The present invention relates to the field of vehicle suspension systems, specifically in the first two embodiments as an air bag spring-dampener on (1) a swing arm suspension with the spring-axle connected via a four-bar linkage and (2) two actuator arms and a rotating actuator shaft, wherein the air bag spring replaces traditional torsion bars or coil springs. These systems are particularly suitable for use on racing cars on dirt or rough surfaces, and more specifically, on an open wheeled sprint, midget, micro-sprint, mini-sprint, championship dirt car, micro-midget, super-modified, championship dirt car, and well-suited for heavier cars such as modified race cars. In competition, such race cars endure severe forces often resulting in loss of wheel to road surface contact, and resulting loss of traction, control and speed. A further refinement by a simplified third embodiment is presented having (1) the front axle supporting a pair of air bags mounted proximate each front wheel, and (2) the rear axle having bird cages mounted adjacent each rear wheel over the wheel bearings and the air bags mounted on extensions. An upper adjustable mount for the air bag having a clamp is welded onto the frame of a sprint car. 
     Accordingly, it is a principal object of the invention to provide an improved lightweight suspension system for a racing vehicle on a dirt track. 
     It is another object of the invention to provide an improved lightweight suspension system which is based on air springs mounted directly on the front axle. 
     It is a further object of the invention to provide an improved lightweight suspension system which is based on air springs mounted on extensions proximate the rear axle inside bird cages. 
     Still another object of the invention is to provide an improved lightweight suspension system having an upper adjustable mount for the air spring with a clamp affixed to the frame. 
     It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes. 
     These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an environmental, perspective view of a first embodiment of an air bag suspension installed for a rear axle of a sprint race car shown in shadow according to the present invention. 
     FIG. 2 is a partially sectioned side elevational view of an air bag draped over its shaping cone and in contact with a four-bar linkage. 
     FIG. 3 is a perspective view of a swing arm suspension utilizing torsion bar springs in a prior art sprint car shown in shadow. 
     FIG. 4 is a top plan view of a sprint car shown in shadow equipped with four air bag springs and bar linkages. 
     FIG. 5 is a sectional side view of a prior art air bag spring as described by FIG. 8 in U.S. Pat. No. 4,858,949 to Wallace et al. 
     FIG. 6 is a sectional side view of a prior art GOODYEAR™ air spring 1S6-023. 
     FIG. 7 is a partially sectioned side view showing the direction of motion and the forces of an air bag spring being compressed by upward forces acting upon a wheel. 
     FIG. 8 is a side view showing the direction of motion and the forces acting upon a wheel being pushed down by an air bag spring. 
     FIG. 9 is a right side elevational view of a sprint car with a second embodiment of the innovative air springs installed in the front and rear. 
     FIG. 10 is a front elevational view of the second embodiment of the innovative air springs for the front axle in a sprint car. 
     FIG. 11 is a rear elevational view of the second embodiment of the innovative air springs for the rear axle in a sprint car. 
     FIG. 12 is an elevational side view of an actuator shaft in the second embodiment. 
     FIG. 13 is a schematic front elevational view of a third embodiment for a front axle, wherein the pair of air spring supports are directly connected by a lower mounting plate to the front axle housing and the bird cages with the adjustable upper mount movable in a clamp welded to the vehicle frame. 
     FIG. 14 is a schematic front view of the third embodiment for a rear axle, wherein the air springs are directly connected to the bird cages or housings for the wheel bearings. 
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The first embodiment 8 of the present system incorporates a four-bar linkage system connecting an axle swing arm suspension system to an air bag spring dampening system. 
     FIGS. 3,  5  and  6  depict prior art suspension systems with air bag springs. In FIG. 3, a sprint car  18  having a frame  330  supported in the rear by a rear axle  180  having a triangular carrier hub  310  at each end. A pair of torsion bars  320  are attached to one carrier hub  310  by a front swing arm  140  and a rear swing arm  350 . FIG. 5 illustrates an air bag spring assembly  22  comprising an air spring  72  having a top cover  73  and self-sealing beads  80  mounted on a movable piston  66  over a cup  64  which is attached to a top mounting plate  58  on a terminal end of a trailing arm  56 . FIG. 6 shows the aforementioned GOODYEAR™ air bag spring 1S6-023 as  24  in an air spring assembly  20  having a top cover  26  and a cup  28  secured by self-sealing tire beads  30 . 
     Turning to the first embodiment  8  of FIGS. 1,  2  and  4 , an air bag spring  150  is draped over an inverted cone  160  (FIG. 2) Such air bag springs  150  are available through GOODYEAR™ or FIRESTONE™ with GOODYEAR™ bag number 1S6-023 serving as an optimal choice. A wide variety of air bags are available with varying size and stiffness. The cone  160  provides support toward shaping and holding up the air bag. The draped air bag provides a spring resistance to an input link of a four-bar linkage, having four pivot joints interconnecting the four bars. The appearance of first, second, third and fourth structural members may be described out of numerical sequence for the sake of brevity and the sake of understanding of functional relationships. 
     The input link  110  has a first pivot joint  116  and has an end  117  in contact with the air bag spring  150 , the contact generally being located at the top of the air bag spring  150 . The input link  110  is in rotational contact about the first pivot joint  116  with the air bag spring  150 , whereby substantially antagonistic oppositional forces from the air bag  150  are applied against the input link  110 . 
     The input link  110  is attached, at the end  119  distant to the air bag, to a second pivot joint  118 . Connected to the second pivot joint  118  is a second coupler link  130  functioning as a push rod. Between the air bag spring  150  and the second pivot joint  118  is the first pivot joint  116 . The first pivot joint  116  serves as a second fulcral point. Pivotally attached at the first pivot joint  116  is a first coupler link  120  functioning as a pull rod. At the end  121  (FIG. 2) of the first coupler link  120 , distant from the input link  110 , is a third pivot joint  146  attached to the frame or chassis  170  of the vehicle. Also pivotally attached on the frame or chassis  170  at the third pivot joint  146  is a swing arm  140 . The distant end  141  of the swing arm  140  is attached to a carrier hub  310  (FIG. 3) on the vehicle axle for live axles or half shafts, or directly to the axles for wheels not attached to rotating axles. This attachment to the carrier hub  310  or axle  180  will generally be a pivotal link (not shown). Orienting the swing arm  140  longitudinally parallel to the chassis and perpendicularly to the respective axle simplifies chassis construction and facilitates suspension adjustment and maintenance, though swing arms may be oriented in numerous other directions. The front swing arm  140  has a fourth pivot joint  148  located between the third pivot joint  146  and the axle  180 . Pivotally attached at the fourth pivot joint  148  is the push rod coupler link  130 . 
     Referring to FIG. 7 which shows relative force vectors to describe the invention&#39;s action and reaction, a rise in the wheel relative to the chassis typically occurs due to an upward force  710  at the ground, resulting from factors such as (1) a rise in the surface such as a bump or hill, (2) a downward force on the chassis as the bottom of a hill, trough or hole, (3) the chassis rolling in the direction of the wheel in turning a corner, and (4) acceleration (rear wheels) or deceleration (front wheels). The forced rise in the wheel in turn forces (at  720 ) the swing arm  140  up at the axle connection, which in turn pushes (at  730 ) the second coupler link or push rod  130  up. The push rod  130  then pushes the attached end  119  of the input link  110  up, which forcibly pivots (at  740 ) the input link  110  about the first fulcral point (first pivot joint  116 ) resulting in the end of the input link  110  pressing down (at  750 ) in contact with the air bag spring  150 . The force  750  acts downwardly, allowing the arm of the input link  110  to continue to pivot until the opposing force vector associated with pressure in the air bag spring  150  is equalized. In other words, the rotational force from the input link  110  is antagonistically counteracted such that the forces come into balance and into fulcral equilibrium. 
     Alternately, as suggested by FIG. 8, weight may be transferred from the wheel  190  (FIG. 1) as the road drops away from it, such as by entering a hole, cresting a bump or hill, or the car rolling away from the wheel  190  during cornering, deceleration (rear wheels), or acceleration (front wheels). Such events all may result in a reduction in upward force at the wheel. This reduction in weight on the wheel permits the air bag to force (at  810 ) the arm of the input link  110  up, forcibly rotating (at  820  on the first coupler link  120 ) the input link  110  about the first fulcral point or the first pivot joint  116 , thereby transferring force along vector  830  down on the end of the input link  110 , opposite the force vector  810  of the expanding air bag spring  150 . This in turn results in a vector force  840  longitudinally directed down the push rod or second coupler link  130 , thereby forcing (at  840 ) the front swing arm  140  down. This force  840  in turn exerts a transferred downward force  850  onto the axle  180  (not shown), until such point as the force  810  exerted by the air bag spring  150  and the upward wheel force  710  (FIG. 7) are fulcrally balanced in equilibrium. 
     Additionally, the four-bar linkage achieves a positional offset for the point of contact with the air bag spring  150 . This permits the input link  110  of the four-bar linkage to come in contact with the air bag spring  150  at a point well clear of the ground. 
     As depicted in FIGS. 1 and 2, the four-bar linkage provides a means for adjusting spring coefficients independent of air pressure and air bag changes. The four-bar linkage can be used to increase or decrease the effective spring coefficient as seen at the axle by adjusting the travel of the input link adjoining the air bag. The effective spring coefficient is adjusted by the following equation with the angles and distances depicted in FIG.  2 . 
     
       
           F   effective =( F   actual )×(( A+B )/ B )×[cos (theta 1)]×([ C/D ) cos (theta 2)] 
       
     
     where: 
     A=the distance between the wheel center and the fourth pivot joint  148 ; 
     B=the distance between third pivot joint  146  and the fourth pivot joint  148 ; 
     C=the distance between the first pivot joint  116  and the second pivot joint  118 ; 
     D=the distance between the first pivot joint  116  and the air bag spring  150 ; 
     Theta 1=the angle formed by the swing arm  140  and the second coupler link  130  closest the air bag spring  150  about the inside of the fourth pivot joint  148 ; and 
     Theta 2=the inside angle formed by the second coupler link  130  and the input link  110  closest the air bag spring  150  about the inside of the second pivot joint  118 . 
     The linkage adjustments increase or reduce the force maintained on the axle with respect to axle travel. The linkage adjustment may be readily facilitated by drilling a plurality of holes  112  (FIGS. 1 and 2) in the input link  110  and repositioning the first pivot joint  116 , or fulcral point which in turn adjusts variables C, D and Theta  2 . 
     As a portion of the spring character of the airbag is obtained through air-compression and expansion, the airbag provides a non-linear resistance to the arm travel, thus creating an inherently damped spring due to energy losses associated with compression and expansion of gases. 
     Due to the relatively low viscosity of air, an airbag has a higher and broader frequency response than traditional dampening devices such as shock absorbers using high viscosity fluids. This results in a smaller portion of the high speed vibrations that are likely to be found on bumpy surfaces such as dirt courses to transfer via the suspension to the chassis as the suspension will flex with these high speed movements as contrasted with the slower suspension systems. Likewise, high frequency Fourier components of individual pulses and movements may be readily transferred to the air bag spring  150 , thereby resulting in lesser values for the derivatives of the displaced wheel distance with respect to time, such as acceleration and over the course of the travel of the swing arm  140 . 
     The second embodiment  10  illustrated in FIGS. 9-12 employs a first inside actuator arm  12  acting on an air bag spring  150  pressurized by an air hose  13  for each wheel  190  on the front axle  14  and the rear axle  16  of a sprint car  18 . The first inside actuator shaft  12  has a distal end connected directly to a hollow rotating actuator shaft  32  housed inside a horizontal frame tube  34  consisting of three separate frame supported sections. A second outside actuator arm  36  has a first end  38  connected to the housing of the axle  14  or  16  and a second end  40  connected to an outside end of the rotating actuator shaft  32 . The inside actuator arm  12  is provided with a splined hole which is slotted at the end of the arm for clamping with a bolt (not shown) onto one of the splined ends  33  of the rotating hollow shaft actuator shaft  32  and further protected by a bushing  42  as shown in FIG.  12 . The inside actuator arm  12  can have a series of holes for saving weight (not shown). 
     As shown in FIG. 10, an additional frame element  44  can be provided for supporting the air bag spring  150  on top and a circular support plate  46  on the bottom which is attached to the first inside actuator arm  12 . Thus, the second embodiment system  10  again provides a lightweight but durable suspension system for a sprint car. 
     In a third embodiment  49  illustrated in FIG. 13 (front axle  50 ) and FIG. 14 (rear axle  51 ), another support means is provided for the air bags  52  having air intake stems  68 . In FIG. 13 a clamp  53  having a ring  54  with an apertured extension  55  supports the upright post  57  having peripheral stops  59  of the circular upper mount  60  of the air bag  52 . The clamp  53  can be either welded or fastened tightly by fasteners (not shown) onto the frame  61 , and is utilized for supporting the air bags  52  for both the front axle  50  and rear axle  51 . 
     On the front axle  50 , the air bags  52  for the front wheels  69  are directly connected to circular metal plates  62  welded onto the axle  50 . For the rear axle  51  the bird cages or housings  63  hold the bearings  65  (hidden). The wheel bearings  65  are sealed roller bearings. A wedge shaped metal lower mount  67  extending from and welded to the bird cage  63  supports the air bag  52  for each rear wheel  70 . The wheel bearings  65  and bird cages  63  are attached to the rear axle  57  by sliding over the ends of the axle. 
     It should be noted that there is both a reduction in weight associated with the use of air bag springs over metal coils or torsion springs and a reduction in unsprung weight, both of which will improve the handling of the vehicle. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.
A vehicle air bag spring suspension system utilizing a swing arm as a member of a four-bar linkage subsystem wherein the suspension system with the airbag spring is compressed by the linkage opposite the swing arm's fulcral point relative the supported wheel. The air bag further serves as an inherently, partially dampened spring having a non-linear spring compression rate, so as to firmly keep the vehicle tires firmly planted to a rough surface. A second embodiment employs two actuator arms per wheel, wherein one inside actuator arm contacts a fixed air bag spring and cooperates with the other outside actuator arm and a rotating actuator shaft inside a frame tube to dampen wheel movement. A third embodiment employs the air spring supports directly connected to the bird cages or the housings for the bearings for both the front and rear axles.