A vehicle comprising: - a first frame portion comprising at least two wheels in tandem; - a second frame portion comprising at least two wheels in tandem; - means for linking said first frame portion to said second frame portion, so that the vehicle can assume at least an equilibrium original position, wherin; said linking means are articulated, the arrangement being so that each frame portion has a degree of freedom of rotation around a longitudinal axis XX and a degree of freedom of rotation around a transversal axis ZZ defined with respect to the vehicle running direction, said first and second frame portion being restrained therebetween in the rotation around the axis XX and independent in the rotation around the axis ZZ, characterized in that: said vehicle comprises first elastic means to bring back said vehicle into said original position with respect to the longitudinal axis XX and second elastic means to bring back said vehicle into said original position with respect to the transversal axis ZZ, further comprising an intermediate frame and wherein said linking means comprises two upper linking crossbars (04, 05) and one lower linking crossbar between said first and second frame portion (01, 02) and said intermediate frame, wherein: - the linking points between said intermediate frame and said upper crossbars (04, 05) are articulated, with two degrees of freedom around the longitudinal axis XX and the vertical axis YY; - the linking point between said intermediate frame and said lower crossbar is articulated with one single degree of freedom around the longitudinal axis XX. - the linking points between said upper (04, 05) and lower crossbars and said first and second frame portion (01, 02) are articulated, with three degrees of freedom around the longitudinal XX, vertical YY and transversal ZZ axes. - a first frame portion comprising at least two wheels in tandem; - a second frame portion comprising at least two wheels in tandem; - means for linking said first frame portion to said second frame portion, so that the vehicle can assume at least an equilibrium original position, wherin; said linking means are articulated, the arrangement being so that each frame portion has a degree of freedom of rotation around a longitudinal axis XX and a degree of freedom of rotation around a transversal axis ZZ defined with respect to the vehicle running direction, said first and second frame portion being restrained therebetween in the rotation around the axis XX and independent in the rotation around the axis ZZ, characterized in that: said vehicle comprises first elastic means to bring back said vehicle into said original position with respect to the longitudinal axis XX and second elastic means to bring back said vehicle into said original position with respect to the transversal axis ZZ, further comprising an intermediate frame and wherein said linking means comprises two upper linking crossbars (04, 05) and one lower linking crossbar between said first and second frame portion (01, 02) and said intermediate frame, - the linking points between said intermediate frame and said upper crossbars (04, 05) are articulated, with two degrees of freedom around the longitudinal axis XX and the vertical axis YY; - the linking point between said intermediate frame and said lower crossbar is articulated with one single degree of freedom around the longitudinal axis XX. - the linking points between said upper (04, 05) and lower crossbars and said first and second frame portion (01, 02) are articulated, with three degrees of freedom around the longitudinal XX, vertical YY and transversal ZZ axes.