3 or more sub units in the example depicted in fig1 collapsible frame 12 comprises of a top sub unit 12 a a back sub unit 12 b a bottom sub unit 12 c and a front sub unit 12 d the four sub units 12 a 12 d are pivotally connected to construct a collapsible parallelogram frame in which sub units 12 a and 12 c are substantially parallel to each other and sub units 12 b and 12 d are substantially parallel to each other accordingly the angle between each consecutive pair of sub units of frame 12 may be changed when frame 12 is in its fully unfolded position that angle is substantially a right angle but these angles of the unfolded position may be set to a different set of angles as desired when in unfolded position sub units 12 b and 12 d may further function as supporting legs for device 10 further sub unit 12 b may further be used to affix device 10 a stabilizing steady part such as a wall of a room not shown or the like front sub unit may be used as depicted in fig1 for the installation of the user 39 s handles top sub unit 12 a may also be used for supporting user 39 s seat 22 bottom sub unit 12 c may be used for supporting the pedal mechanism 14 back sub unit 12 b may also be used to support driving gear 18 and flywheel 20 el 18 may be installed with its turning axis substantially parallel to.