In this paper we present an approach for analyzing the inertial effects of changing the wing shape for steering a bat-like robot. Using BaTboT, a robotic platform with massive morphing-wings, we have estimated the generation of pitching and rolling torques, which are directly related to forward and turning maneuvers. Results let us conclude that faster retraction of the wings during the upstroke, and slower extension during the downstroke increase both pitching and rolling torques in about 50% compared to those wingbeats with equal periods for retraction/extension. Also, we determined that the pitch torque generation is proportional to 0.6m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/f</sup> , whereas the rolling torque is promotional to 0.1m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1/f</sup> , being m the mass of the robot and f the flapping frequency of the wings.