Evo Längpendel

Hi, I have a 16 inch front wheel with 130/16/60 and 240/50 on the rear front of my Evo, and from 110 km/ a light longitudinal pendulum is created. How can you fix it? One says to upgrade to 16 or 17 inch front, the other recommends the torque plate or yet a steering damper? First of all, thank you for your idea.