Loading tailgate

The vehicle loading platform system (10) has a platform (18), raised and lowered by a parallelogram mechanism. The lifting/lowering mechanism has two horizontal and spaced carrier arms (12,13), locked together by an elastically distorting force train. A lifting cylinder (15) is asymmetrically against a carrier arm (12), and at least one compensating cylinder (120) acts on the force train, to compensate at least partially for its distortion. The force train is formed by a torsion/bending profile (17) fitted to the two carrier arms by mountings (170,171).