Velocity field of the H I model cubes. Left panel. Model built to match the observed S-shape of the kinematical major axis (Fig. 10). Right panel. The same model as in the left panel, but now allowing for a variation of v_sys with radius in order to match the observed U-shape of the kinematical minor axis, too (Fig. 10). We interpret the better match of the latter model to the data in terms of ram pressure changing the outer gas kinematics.