The paper contains suitable methodics to obtain optimal part design due to operational (static) load cases. The subject of optimization is an upper rocker of a special mountain bike frame. To obtain optimized part design a topology optimization method combined with a numerical shape optimization was used. Optimized part was manufactured by Selective Laser Melting technology. The paper begins with introduction of part's function and its operational load. Then used optimization tools are introduced and initial conditions sensitivity demonstration is performed. Manufactured part with optimized design is shown at the end of the paper.