In this paper one presents the new concept of a rocker-bogie suspension where the suspension members can change their length. As a result of this action the frame with suspension is able to adjust to the specific environmental conditions. The main problem with the designed suspension system is a fact that with an extension of the suspension members their slenderness increases as well as final displacements. The solution of this problem is not so simple because the construction must meet the specific requirements due to participation of the mobile platform in different competitions. In the presented results of numerical simulations one shows an influence of the different materials on stress and displacements magnitudes of suspension members when the mobile platform hits an obstacle. This situation allows one to test different engineering solutions in the worst case scenario when suspension elements may be damaged. Finally the optimum design is presented.