LONDON, England - Lewis Hamilton's main problem as he grapples to get up to speed with his Mercedes team mate Nico Rosberg is the W04 car's brakes, it has emerged.Beaten to pole position by Rosberg on the last three outings, Hamilton departed Monaco having watched the sister car stroll to victory - vowing to get his act together".He is quoted by France's L'Equipe as admitting that the biggest difference between his new Mercedes and his McLarens of past seasons are the brakes.DIFFERENT CARSHamiltons aid: "At McLaren, I had 100% confidence in the car, and I'm working to regain that confidence. The setup and the brakes are very different to what I was used to."It's an overall feeling that's hard to explain. It's not a problem of concentration, it's just confidence in the car." Stay with Wheels24 for the 2013 Formula 1 season – fresh reports every day.