Suspension group for motor vehicles comprising - a main spring which extends between a first and a second end (20,24) of the group, influencing them elastically along a working axis (X-X), - a main damper connected in parallel to said main spring so as to exercise a damping action of the relative movement between said first and second ends (20,24), induced and/or countered by the main spring, - said main spring being pre-loaded by pre-loading means which together influence the spring in compression and impose a rest length thereon (L 0), namely the length assumed by the spring when there are no further external loads on the first and/or on the second end (20, 24) of the group except for the pre-load caused by the pre-loading means, - in which the first and second end (20, 24) are connected kinematically to a first and a second mass (28,32) of the motor vehicle respectively, the first mass being a mass suspended by the suspension group and the second mass being a non-suspended mass and comprising a wheel or a portion of connection/support to a wheel of the motor vehicle, - wherein the non-suspended mass comprises a rear wheel of the motor vehicle and a part of the fork supporting said rear wheel and wherein the suspended mass comprises or is mechanically attached to a support frame of the saddle of the motor vehicle, - wherein between at least one of said first and second ends (20,24) and the respective suspended/non-suspended mass (28,32) at least one kinematic connection is placed, in series with the main spring which permits a supplementary stroke between the end (20,24) to which it is attached and the relative adjacent suspended/non-suspended mass (28,32), said supplementary stroke increasing the distance between the suspended and non-suspended mass (28,32) imposed by the extension of the main spring, the suspension group being characterised in that - the kinematic connection is influenced by the load of the suspended mass, so as to prove retracted, namely not to provide any supplementary stroke, until the length of the main spring is less than or equal to the rest length (L 0), and so as to extend under the effect of the non-suspended mass, providing a supplementary stroke, after the main spring has extended reaching its rest length (L 0), wherein the kinematic connection comprises a prismatic guide which permits a reciprocating rectilinear movement along a kinematic connection axis (W-W) parallel to said working axis (X-) of the main spring. - a main spring which extends between a first and a second end (20,24) of the group, influencing them elastically along a working axis (X-X), - a main damper connected in parallel to said main spring so as to exercise a damping action of the relative movement between said first and second ends (20,24), induced and/or countered by the main spring, - said main spring being pre-loaded by pre-loading means which together influence the spring in compression and impose a rest length thereon (L 0), namely the length assumed by the spring when there are no further external loads on the first and/or on the second end (20, 24) of the group except for the pre-load caused by the pre-loading means, - in which the first and second end (20, 24) are connected kinematically to a first and a second mass (28,32) of the motor vehicle respectively, the first mass being a mass suspended by the suspension group and the second mass being a non-suspended mass and comprising a wheel or a portion of connection/support to a wheel of the motor vehicle, - wherein the non-suspended mass comprises a rear wheel of the motor vehicle and a part of the fork supporting said rear wheel and wherein the suspended mass comprises or is mechanically attached to a support frame of the saddle of the motor vehicle, - wherein between at least one of said first and second ends (20,24) and the respective suspended/non-suspended mass (28,32) at least one kinematic connection is placed, in series with the main spring which permits a supplementary stroke between the end (20,24) to which it is attached and the relative adjacent suspended/non-suspended mass (28,32), said supplementary stroke increasing the distance between the suspended and non-suspended mass (28,32) imposed by the extension of the main spring, the suspension group being characterised in that - the kinematic connection is influenced by the load of the suspended mass, so as to prove retracted, namely not to provide any supplementary stroke, until the length of the main spring is less than or equal to the rest length (L 0), and so as to extend under the effect of the non-suspended mass, providing a supplementary stroke, after the main spring has extended reaching its rest length (L 0), wherein the kinematic connection comprises a prismatic guide which permits a reciprocating rectilinear movement along a kinematic connection axis (W-W) parallel to said working axis (X-) of the main spring.