Abstract: A cushion adjusting assembly of an exercise machine comprises a post; a top end of the post having a combining portion; an adjusting rod and an ejecting unit being pivotally installed in the combining portion; the adjusting rod having at least one inclined surface; and the ejecting unit having at least one inclined surface corresponding to the inclined surface of the adjusting rod; and an adjusting portion having two clamping plates and a stud; a clamping section being formed between the two clamping plates; the stud passing through the two clamping plates so that the two clamping plates are positioned on the combining portion; and the stud passing through the two clamping plates so that the adjusting portion is positioned on the combining portion; the stud passing through the combining portion so as to position the ejecting unit and the adjusting rod.

Abstract: Various linkage arrangements link rotation of left and right cranks to movement of left and right foot supports through generally elliptical paths. The linkage arrangements may also link rotation of the cranks to reciprocal movement of left and right handles. Also, connection points defined by the linkage arrangements may be moved relative to one another and/or a supporting frame to adjust the size, shape, and/or orientation of the elliptical paths.

Abstract: An exercise machine includes: a flywheel mounted rotatably to a support frame; a crank wheel mounted rotatably to the support frame; a transmission belt trained on the flywheel and the crank wheel; and a pressurizing wheel mechanism including a mounting seat mounted to the support frame, upper and lower pressure wheel units provided pivotally on the mounting seat, and upper and lower limiting members mounted to the mounting seat. The upper and lower pressure wheel units respectively have upper and lower pressure wheels biased to move in first and second directions so as to press and tense upper and lower segments of the transmission belt that extend between the flywheel and the crank wheel. The upper and lower limiting members limit movement of the upper and lower pressure wheel units in directions opposite to the first and second directions, respectively.

Abstract: An exercise device providing a fore and aft horizontal component of striding motion that is dynamically user-defined, while providing a vertical component of the motion that is maintained on a predetermined vertically reciprocating path in some embodiments. The exercise device guides the user's foot in a pseudo-elliptical stride path, while providing a dynamically variable stride length that allows the user to move with a natural stride length. The exercise device allows tall and short users to extend or curtail the stride length to match their natural stride lengths. The length of the reciprocating path is dynamically adjusted during the exercise operation without equipment adjustments by changes in the length of the stride input by the user at a pair of foot engagement pads disposed on laterally spaced apart foot support members.

Abstract: A miniaturized track exercising device includes a chassis on which a counterweight wheel set is provided. The counterweight wheel set is provided with a resistance adjusting unit. Two crank arms extend in opposite directions and are arranged on opposite sides of the counterweight wheel set. Each crank arm is pivotally connected to a pedal in an offset manner. The pedals are provided with a guide rail unit that is opposite to the crank arms with respect to the pedals and that provides a pivot joint and a fulcrum. Thus, when the pedals are being treaded, with the counterweight wheel set inducing a sufficient resistance that is adjusted with the resistance adjusting unit and the guide rail unit providing support against gravitational force acting on the pedals while the pedals undergo track motion, the pedals are constrained by the guide rail unit to generate an elliptical track motion.

Abstract: An elliptical exercise apparatus includes two cranks disposed rotatably on a frame and rotatable about a common crank axis, two rails each disposed fixedly on the frame and having a non-circular guide slot, two extension links connected respectively, radially, and slidably to the cranks and mounted with rollers disposed respectively and movably within the guide slots, two connector members disposed on the frame and reciprocatable along a longitudinal direction of the frame, and two foot links each having a first end connected pivotally to the corresponding extension link and a second end connected pivotally to the corresponding connector member. When the rollers move along the rails, the extension links are extendable and retractable relative to the cranks, respectively.

Abstract: An exercise device can include a pair of pedal members, each of which can be rotatably connected on at least one end to a planet gear that is rotatable about a sun gear on each side of the device. The pedal members and the planet gears can be rotated to provide an elliptical exercise motion. The device can include a mechanism for simultaneously rotating each of the sun gears together to change the orientation of the elliptical exercise motion relative to a user. The orientation of an elliptical exercise motion can be changed dynamically from one orientation to another, for example, from horizontal to uphill or downhill, during a particular workout period. The exercise device can change the orientation of an elliptical exercise motion while maintaining a user's ankles at a substantially constant angle during the exercise cycle.

Abstract: A drive system for a magnetic resistance exerciser includes a fixed wheel and at least one rotatable wheel which are rotatably connected to the weight wheel and the fixed wheel by two respective belts. The fixed wheel and the weight wheel share a common shaft which is perpendicularly connected with a link and the at least one rotatable wheel is rotatably connected to an extension on an end of the link. When rotating the shaft, the link rotates and the at least one rotatable wheel rotates about the shaft and the extension simultaneously so that the rotational speed of the weight wheel can be increased without increasing the whole system.

Abstract: A fixed safety handle of an elliptical cross trainer includes a fixed safety handle disposed near the top of a primary upright frame of an elliptical cross trainer, extended in direction of the operator, and bent in U-shape. The fixed safety handle includes a first holding member extending downwardly from both ends of the fixed safety handle and a second holding member extending laterally from the first holding member in direction to the outside such that the second holding member is located beyond the movement path of movable handles. In this way, the safety in getting on or stepping off the elliptical cross trainer can be ensured.

Abstract: An exercise apparatus includes left and right rigid connector links having first portions rotatably connected to respective cranks, second portions constrained to move in reciprocating fashion, and third portions connected to respective foot supports. Intermediate links are also interconnected between respective cranks and respective foot supports. The resulting assembly links rotation of the cranks to movement of the foot supports through generally elliptical stepping paths. The connection points may be moved relative to one another and/or a supporting frame to adjust the size, shape, and/or orientation of the paths.

Abstract: An elliptic motion exercise machine includes a frame, on which a reciprocating motion mechanism, a circular motion mechanism and two linking members are provided. Two parallelogram linkage mechanisms are movably mounted on the frame and connected to the linking members. Two foot panels are fixed on the parallelogram linkage mechanisms respectively. The parallelogram linkage mechanisms keep the foot panels in fixed slops in the entire motion, such that when an user stands feet on the foot panels and exerts the foot panels, toes of user's feet moves in a speed that is substantially identical to that of use's heels.

Abstract: An exercise apparatus is disclosed herein, including a frame, a rotating assembly, two supporting rods, two swing arms, two links, and two pedals. The front ends of the supporting rods are connected respectively to two connecting points of the rotating assembly, and the rear end of each supporting rod moves back and forth along a corresponding track. The front ends of the links are connected respectively at two swing ends of the swing arms. Each pedal is mounted at the rear end of a corresponding link and pivotally coupled to a corresponding supporting member. The distance between the bottom of a circular path of the connecting points and the tracks is smaller than 10 cm. The length of the supporting rod is smaller than two times diameter of the circular path. The longitudinal horizontal distance between the front edge of the closed path and the rear edge of the circular path is smaller than 20 cm. The rear ends of the supporting rods are located between the front ends and rear ends of the pedals.

Abstract: A bicycle trainer adapted to support a conventional bicycle with the front wheel removed. The bicycle is attached to a pivot frame at the front forks and the rear axle. The pivot frame is pivotably attached to the base frame and supported in a substantially upright position by springs. Both the bicycle and pivot frame pivot about an imaginary tire contact-line, which simulates real bicycle riding conditions associated with bicycle sprinting and hill climbing.

Abstract: Static pedalling fitness apparatus (1) that, with great accuracy, simulates the real excercise of pedalling on a conventional road biclycle while standing up and swinging the bicycle sideways. For this purpose, the fitness apparatus (1) comprises a fixed part (2) which is basically unmovable with respect to the floor, a movable part (3) which is capable of swinging laterally with respect to the fixed part (2) and which includes the set of pedals (4) and the seat (5), and another tilting part that is the handlebar (6) of the apparatus (1). The handlebar (6) is capable of oscillating separately from the oscillation of the movable part (3), i.e. the handlebar (6) presents a relative swinging movement with respect to the set of pedals (4) and the seat (5).

Abstract: An improved foot support platform for cardiovascular exercise machines provides various adjustable platform configurations. The different configurations allow the user to target specific muscle groups more easily and prevent the user's feet from falling asleep while exercising.

Abstract: A variable stride exercise apparatus is described. The apparatus may include a frame. A crank system may be coupled to the frame. The crank system may include crank rollers. In certain embodiments, arm links may be coupled to the frame. The apparatus may include foot members that travel in multiple paths. The foot members may be coupled to the arm links. The foot members may be coupled to the crank system through cam devices. The crank rollers may be located below the foot members such that at least a portion of a user's foot passes above the crank roller during use of the apparatus. A user of the apparatus, by varying the user's stride, may selectively vary a path of the foot members. The foot members may be cross coupled so that the left foot member moves in opposition to the right foot member.

Abstract: An exercise machine includes a pair of slide members having front ends connected to a crank unit for turning along with the crank unit and rear ends linearly slidable on a support. A pair of reciprocating members are mounted on the support for reciprocating forward and backward. A pair of foot support members each have a front pivotal end and a rear free end. The front pivotal end of each foot support member is connected pivotally to one of the slide members between the front and rear ends of the slide member. Each foot support member is connected to one of the reciprocating members rearwardly of the front pivotal end.

Abstract: An exercise machine for providing a motion, climbing a hill with hand weights, includes single swing arms with fixed foot platforms and forwardly extending substantially horizontal handles. The swing arms and foot platforms are interlocked through a flexible link and pulley arrangement. The machine has provision for adjusting the length of the travel arcs, which changes length of stride of the foot platforms, and the climbing effect, which alters the workout intensity. The machine of the invention is readily foldable for storage.

Abstract: An exercising device includes a base frame, two crank shafts rotatably mounted on the base frame and each having two opposite bent end portions, and two pedals each mounted between the two crank shafts and each having two opposite end portions each pivotally mounted on and movable with the respective bent end portion of the respective crank shaft respectively. Thus, the user can step the two pedals to rotate the two crank shafts simultaneously so as to obtain an exercising effect.

Abstract: Chair-rotating control mechanism applied to sport apparatus, wherein driven gear sector is to drive the connected eccentric shaft to rotate, chair pivoted with an eccentric shaft is driven by rotating shaft of pedal or decelerating motor, or both of them move together as power source, this control mechanism can be applied to bicycle, exercising bicycle and AB chair to control rotation of chair, so that it can turn around waist and hip of rider when riding on it to do exercise.

Abstract: A exercising vehicle includes a base frame, two crank shafts rotatably mounted on the base frame and each having two bent end portions and two straight distal ends each connected to the respective bent end portion, two pedals each mounted between the two crank shafts and each having two end portions each pivotally mounted on the respective bent end portion of the respective crank shaft, and a plurality of wheels each secured on the respective straight distal end of the respective crank shaft. Thus, the user can step the two pedals to rotate the two crank shafts simultaneously to rotate the wheels so as to move the exercising vehicle, thereby obtaining an exercising effect.

Abstract: An elliptical exercise machine, including a gearbox, a generally flat contact surface, a first elongated footrest support member mechanically coupled to the gearbox and extending to the flat contact surface, a second elongated footrest support member mechanically coupled to the gearbox and extending to the flat contact surface, and an elastic coupler removably connected between the first and second elongated footrest support member. The contact surface is generally flat and described by a first axis and a second orthogonally oriented axis. The gearbox independently governs the motive resistance and travel path of each footrest support members. The each footrest support member rollingly cooperates with the contact surface, and each first and second elongated footrest support member may cooperate with the support surface independently of the other respective footrest support member. Each footrest support member is free to move in the plane of the flat contact surface, i.e.

Abstract: A folding pedal is disclosed to include a pedal body, which has a center spindle pivotally connectable to a crank of a bicycle, and two pedal blocks that are respectively pivotally coupled to top and bottom sides of the pedal body and turnable relative to each other between a first position where the two pedals are closed together and extending in same extending direction of the center spindle and a second position where the two pedals are opened and respectively extending in direction perpendicular to the center spindle.

Abstract: The present invention relates to a low-impact, time-efficient way to exercise both the cardio-respiratory system and the muscular system, particularly the abdominal and back muscles. The exerciser uses his muscles to oscillate a pivoted carriage within a frame. In one embodiment, the exerciser pedals a crank to pump hydraulic fluid through a hydraulic circuit to a hydraulic cylinder connected between the carriage and the frame so as to urge the carriage to oscillate with respect to the frame. A limit sensor detects when the carriage is positioned at one extreme of its oscillation and signals the hydraulic circuit to reverse the flow of hydraulic fluid to the hydraulic cylinder.

Abstract: A convertible cycle exerciser. The exerciser, moveable between a first position and at least one second position, comprises a base and a supporting member extending upwards therefrom with a main exerciser body pivotally connected to the supporting member by at least one pivot point. In the first position, force is applied to crank arms via a user's feet in a conventional cycling mode, and in the at least one second position, applied to the crank arms with a user standing and operating the exerciser via hands and arms. An adjustable resistance mechanism acting on a first rotating member to vary the load requirement is controlled by at least one resistance control conveniently accessed in each of the first and at least one second positions. Movement of the exerciser between the first and at least one second positions is facilitated by operation of a simple release mechanism.

Abstract: A training toy and exercise device. A large frame supports a rear wheel and a front wheel. The front wheel is mounted in sized openings in the frame and is controlled by a handle bar. There are no pedals, chains, cranks controlling the operation of the device. A user will sit on the seat and use the user's legs to propel oneself unless the user is coasting. Under those circumstances the user's legs will rest on pegs. The device will find its primary use as a toy for small children who have not yet learned to ride a bicycle. Using this device a child can learn to ride a bicycle and balance himself on a two wheeled vehicle without concern for falling since at anytime the child's legs readily reach the ground given the vehicle's small size and low center of gravity.

Abstract: A pedaling exerciser with a twister device has a base, a twister device mounted on the base, a pedaling assembly combined with the twister device, and an optional shell covering crank drums of the pedaling assembly. The twister device is composed of an intermediate plate and a rotating plate mounted. The intermediate plate is secured on a central shaft of the base and has multiple balls rotatably mounted thereon. The rotating plate rotatably mounted on the intermediate plate and has a bearing attached thereon around the central shaft to keep the rotating plate stable during rotation. Moreover, the rotating plate has a pin assembly movably engaged the intermediate plate to lock the twister device. By having the twister device, the pedaling exerciser selectively works pedaling and twisting functions at the same time.

Abstract: The invention is an exercise device comprising (i) a frame, (ii) first and second foot supports operably associated with the frame for traveling in a forward and backward direction along a closed loop path relative to a transverse axis defined by the frame, (iii) a means effective for sensing the direction of travel of the foot supports along the closed loop path as between the forward and the backward directions, and (iv) a means for automatically adjusting the stride length and/or stride height of the closed loop path traveled by the foot supports based upon the sensed direction of travel of the foot supports.

Abstract: The invention relates to a structure of rocker arms with optical sensing control for an exercise apparatus. The rocker arm of an exercise apparatus includes a handgrip. At least an optical sensor in accordance with the invention is positioned within a finger groove of the handgrip. The finger groove is so constructed that its form corresponds to the finger pad of the finger of an operator. Meanwhile, the finger groove is provided with an aperture in which the optical sensing element is hidden. The optical sensing element is connected to a console of the exercise apparatus through a conducting wire for setting different functions (exercise speed, slope or resistance) by means of effective detection signals. Therefore, the exercise apparatus is operable by means that a finger of both hands is slightly moved at fixed point during the exercise session.

Abstract: A pace-adjusting mechanism of an elliptical cross trainer having an electric adjusting mechanism installed at the bottom of a front side of the frame unit. The electric adjusting mechanism includes a motor, a guide spindle sleeve, a telescopic spindle, a slide bar, a U-frame and two connecting rods. Both connecting rods are pivotally coupled to the front end of the treadle plank. The U-frame is pivotally mounted on the frame unit. When the guide spindle sleeve is driven by the motor to create a reciprocating in-place displacement of the telescopic spindle, it results in a change of the connecting angle between the slide bar and the U-frame. In this way, the U-frame changes its supporting angle. Then, the vertical position of the treadle plank and the treadle thereon can be adjusted by the coupling relationship of the connecting rods. Accordingly, the change of the exercise pace can be achieved.

Abstract: An exercise trainer having a first crank arm and a second crank arm respectively connected to a first foot link and a second foot link with foot pedals supported on the foot links, and bearing supports for the foot links removed from the crank arms. A flexible connection connects a ground point, the foot pedals, and the foot links to provide relative movement in a modified ellipse as to the ground point of at least twice the length of each crank arm. A seat is mounted on the trainer having a motor and control for raising and lowering the seat with respect to the foot pedals. The first and second crank arms are connected to a motor for driving the crank arms at a given speed which can supplement a user's effort or provide a load to a user beyond a given speed.

Abstract: An exerciser includes a shaft rotatably disposed on a base, a housing rotatably engaged on the shaft and having a chamber formed by an outer peripheral wall which has a groove, a belt wound around the tube for rotating the housing, a barrel received in the chamber of the housing and secured to the shaft and having a slot. A coil spring is received in the housing and has two ends engaged into the slot of the barrel and the groove of the outer peripheral wall of the housing. A cover includes a space formed by an outer peripheral fence, to suitably enclose the chamber of the housing.

Abstract: An improved wheelchair trainer with independent flywheel resistance for each wheelchair rear wheel. A lever-operated cam raises the wheelchair rear axle by pushing an inclined block against the axle and forces the rear wheels against wheel engagement means. As one or both rear wheels are turned, each wheel engagement means turns a flywheel in proportion to the speed of the wheel. Force and work may be calculated from the measured rotational speed of the flywheels. A hand-cycle attachment may drive the flywheel resistance.

Abstract: A variable stride exercise apparatus is described. A variable stride exercise apparatus may include a frame having a first end and a second end. A crank system may be coupled to the frame. A foot member may be coupled to the crank system. The foot member may include a footpad. A variable stride system may be coupled to the foot member. The variable stride system may be located closer to the second end of the frame than the first end of the frame. The variable stride system may allow a user of the apparatus to vary the length of the user's stride during use of the apparatus. The foot of the user may travel in a substantially closed path during use of the apparatus. At least a portion of the apparatus may remain substantially stationary during use.

Abstract: An angle adjustable pedal assembly for elliptical exercisers includes a pedal frame and a pedal which is pivotably connected to two sides on an end of the pedal frame. Each side wall has a hole with three notches defined in an inside of the hole and the pedal has two connection plates each of which has a reset slot and a set slot which communicates with the reset slot. A pin extends through one of the reset slot and the set slot, and is engaged with one of the three notches in the side walls so that the pedal can be set at different angle relative to the pedal frame by engaging with one of the three notches in the side walls.

Abstract: An elliptical exercise device includes a main frame having a rotary shaft defining an axis, left and right link rods having rear ends connected to the rotary shaft for rotation about the axis, left and right arms connected respectively to front ends of the link rods for reciprocal movement, and left and right foot plates connected pivotally and respectively to the link rods and movable along elliptical paths when the rear ends of the link rods rotate. A guide mechanism is connected to the foot plates and the main frame to restrict movement of the foot plates. Each foot plate is substantially horizontal when moving upward or downward from the lowest or highest point of the corresponding elliptical path.

Abstract: A virtual reality bicycle-training simulation platform is disclosed to include a rotary steering unit and rear wheel rack that support the front and rear wheels of a bicycle and are linked to a multimedia system for outputting a signal to the multimedia system indicative of the biasing of the front wheel of the bicycle and controllable by the multimedia system to impart a damping resistance to the rear wheel of the bicycle.

Abstract: A rotary rehabilitation apparatus for rehabilitation of a person's extremity, including the joints and assorted muscles, tendons, ligaments, that can be tailored to the person's needs based upon their physical size, type of injury, and plan for recovery. The apparatus facilitates the adjustment of the range of motion of the user's extremity in a cycling action by offsetting a moveable lever from a fixed lever at a plurality of angles. As the user's extremity moves in a circular path, the extremity engages in extension and flexion to cause movements in the articulations formed at the user's joints.

Abstract: The present invention discloses a fitness machine with elliptical and stepping functions for integrating a stepping exercise and an elliptic exercise for exercising users' legs as well as a swing exercise for exercising users' arms. The fitness machine comprises a frame, two sliding rods, two pedals, and two support rods. If the two support rods are fixed to the frame, the two pedals will be limited such that the two pedals produce an up-and-down stepping exercise. If the two support rods are fixed to the sliding rods, then the limiting effect of the pedals provided by the support rods will be diminished, so that the two pedals produce a back-and-forth elliptic exercise. Regardless of the stepping exercise or the elliptic exercise, the two swinging arms are linked by the two sliding rods and swung back and forth, so as to provide both exercisers for legs and arms.

Abstract: A unique structure for an indoor exercise bike that provides strength in its design, as well as the flexibility to create an aesthetically appealing frame structure. The monocoque frame design, including two symmetrical halves joined together, forms a very strong, light shell that can take on a variety of shapes and sizes. The seat structure, handlebar structure, drive train and support platforms are all able to be readily attached to the primary frame structure to provide an exercise bicycle that is sturdy, easy to manufacture, and light enough to easily move when necessary.

Abstract: This invention is a quad cycle and exercise apparatus with arm and foot power as propulsion. The rider is upstanding during operation.

Abstract: An elliptical exercise apparatus includes an upstanding support connected to a front end of a base support, a rail assembly provided on a rear end of the base support, a wheel assembly mounted on the front end of the base support, a swing rod connected pivotally to the upstanding support, a slide rod having a rear end slidable forwardly and rearwardly along the rail assembly and a front end connected pivotally to the wheel assembly, a pedal seat connected pivotally to the slide rod, a pedal member mounted slidably on the pedal seat, a first link rod having a front end connected pivotally to the swing rod and a rear end connected pivotally to the pedal seat, and a second link rod having a front end connected pivotally to the swing rod below the first link rod and a rear end fixed to the pedal member.

Abstract: An exercise machine includes a base, a machine frame mounted on the base, and one or more hand grips pivoted to the machine frame. Each of the hand grips is provided with a damping device which is fastened at one end to the base or machine frame, and at the other end to a bottom end of the hand grip.

Abstract: A treadmill assembly that includes a frame and a treadmill belt. In addition, a sensor produces a signal representative of an aspect of the user's position relative to at least one point on the frame. A belt rotation assembly turns the belt with a speed related to the signal. In one preferred embodiment the speed of the belt is inversely proportional to the distance between the user and the front of the treadmill. In another preferred embodiment the treadmill is sized to support a cycle.

Abstract: A variable stride exercise apparatus is described. A variable stride exercise apparatus may include a frame. A crank system may be coupled to the frame. A foot member may be coupled to the crank system. The foot member may include a footpad. A variable stride system may be coupled to the foot member. The variable stride system and the foot member may be coupled such that at least a portion of the variable stride system is under at least a portion of the footpad. The variable stride system may allow a user of the apparatus to vary the length of the user's stride during use of the apparatus. The foot of the user may travel in a substantially curvilinear path during use of the apparatus. At least a portion of the apparatus may remain substantially stationary during use.

Abstract: An exercise apparatus has a linkage assembly which links rotation of an adjustable length crank to generally elliptical movement of a force receiving member. The linkage assembly includes a first link having a rearward end which is rotatably connected to the crank, and a forward end which is rotatably connected to a lower end of a suspended link. An upper portion of the suspended link is rotatably connected to the exercise apparatus frame.

Abstract: An elliptical exercise machine and methods for using the machine where the horizontal length of the stride of the ellipse can be adjusted by the user without the user having to alter the vertical dimension of the ellipse by an equivalent amount. The machine provides for alteration from a rocker bar's distal end following a cam track, whose position is adjustable. The machine may allow for this adjustment to occur during the performance of an exercise routine.

Abstract: A pedal device includes a barrel for attaching to a cycling apparatus and having a fixed seat, a movable seat slidably attached onto the barrel and having a number of recesses facing toward corresponding recesses of the fixed seat, a spring biasing device for biasing the movable seat to move toward the fixed seat of the barrel, and an attachment for attaching to a bicycle shoe and having two end catches for selectively engaging with the recesses of the fixed seat and the movable seat, and for selectively anchoring the bicycle shoe to the seats of the pedal device. The movable seat is movable away from the fixed seat against the biasing device by the attachment.

Abstract: A stroke adjusting attachment for bicycles or the like enables selective changing of the diameter of the orbit which is traveled by a foot pedal to adapt a particular bicycle to persons having different leg lengths or who may have physical impairments which limit foot movement. The pedal is fastened to the attachment rather than being directly secured to a crank arm of the bicycle in the conventional manner. A track member is secured to the bicycle crank arm and the pedal is fastened to a slider which is travelable to any of a plurality of different locations along the track member. Blades extend from the track member adjacent to opposite surfaces of the crank arm thereby maintaining the attachment in a fixed orientation relative to the crank arm. A particular attachment of this form can be fitted onto a variety of crank arms of different sizes and shapes.

Abstract: A combined cycling and stepping exerciser includes a base frame with an upright post, a drive wheel mounted on the base frame, a pair of elongated lever arms with front end portions pivoted to the upright post, a pair of slide seats, and pair of pedal arms disposed on the lever arms. Each of the lever arms has a longitudinal slide groove. Each of the slide seats is coupled to a respective crank arm of the drive wheel, and engages slidably the slide groove in a respective lever arm so as to be slidable along the slide groove. Each of the pedal members has a front end engaging slidably the slide groove in a respective lever arm. A pair of fasteners are operable for fastening rear ends of the pedal members selectively and respectively to the slide seats and to rear end portions of the lever arms.