When I was watchin the time trial today I couldn't help but notice that Alberto keep pushing himself to the back of the saddle after a few revolutions of the pedals. One of the commentators mentioned that he was pulling himself forward with his pedaling motion. It looked like he was sliding forward and correcting this. Could it be that the nose of the saddle was too far down, or that the mechanic messed up, or that something slipped? Is this Alberto's riding style in a time trail?