Mercedes has confirmed one of the main theories behind why George Russell’s car was underweight at the end of the Belgian Grand Prix. Russell took an unlikely victory on the one-stop strategy having climbed up to the lead from sixth on the grid, but during the post-race inspections by the FIA he failed the minimum weight check. According to the FIA, his Mercedes was found to be 1.5kg under the 798kg minimum weight limit. As it is a breach of the F1 technical regulations, Russell was disqualified and second-placed Lewis Hamilton inherited the win. There have been several theories as to why Russ…