Abstract: A planetary gear reduction unit is drivingly connected between the handlebars and front fork of a motorcycle for steering. The handlebar is coaxially mounted for rotation with respect to the front fork of the motorcycle; sector gears are respectively mounted on the front fork and handlebar for respectively engaging rigidly innerconnected spur gears rotatably mounted on a carrier that is fixed to the vehicle frame to provide a gear reduction so that there is a reduction of the angular movement of the fork with respect to that of the handlebar.