As twinaisle stated the pitch trimmer is always hydraulically positivly charged keeping the bogie at a positive angle, meaning the rear wheels touch down first. On retraction the bogie is brought back to a horizontal state by the influence of geometry, the shortening mechanism effectivley pulls the slider into the main fitting and geometrically the bogie then sits at 90 degrees to the legs for stowage into the bay. I am not sure of the angle but it is around 10 degrees but i am able to find it out for you tomorrow.