- Canadian GP - Race
Being stuck behind Rosberg 'cooked' brakes - Hamilton
Lewis Hamilton suspects being stuck behind Nico Rosberg contributed to his rear brake failure at the Canadian Grand Prix.
Mercedes looked set for an easy one-two until lap 36 when Hamilton experienced a high-voltage control electronics failure, causing a permanent loss of MGU-K drive. A lap later Rosberg experienced the same failure and both drivers slowed significantly as a result, allowing the chasing pack to close in.
The MGU-K works by harvesting energy from the rear axle under braking, which actually helps decelerate the car along with the brakes, and then deploying that energy on the straights. A failure of the MGU-K not only reduces power but also puts added strain on the rear brakes, which are smaller this year and controlled electronically to work in harmony with the MGU-K harvesting.
Hamilton's rear brakes eventually overheated and failed on lap 46 just after he got ahead of team-mate at the second round of pit stops.
"We knew as a team that we had some issues some part through the second stint, but we thought it would be okay to manage it and that's why we were going at the pace we were going," Hamilton said. "I jumped him [Rosberg] in the stop and I was thinking 'Wow! Finally! What a great feeling', but then straight away on that lap the brakes failed. There was nothing I could do.
"I was following him [for the first two stints] and the problem is that when you are following someone everything is gaining heat. He was in clear air the whole time in front, so there was not much I could do, and then when I came out in front everything was cooked already. It was an unfortunate day, but the team got 18 points which was good and we move on and hope that we don't have any more DNFs this year."
Mercedes executive director (technical) Paddy Lowe explained the issues faced by the two cars in more detail.
"We experienced a near-simultaneous failure of the MGU-K on both cars just after half distance, which was apparently caused by an issue in the high-voltage Control Electronics which manage the MGU-K," Lowe said. "This meant both cars lost hybrid power from this point onwards and, without the additional braking force of the MGU-K, this also put a much higher load on the rear brakes. Lewis then suffered a complete rear brake failure after his second pit stop, which was a consequence of the MGU-K fault.
"Nico was not affected in the same way and managed incredibly to maintain position from lap 37 to lap 67, making up time in the first and second sectors in order to defend in sector three, when he was considerably down on power."
Hamilton is now 22 points behind Rosberg in the standings, but is confident he can bounce back.
"I've had a lot of work to do since day one and now it's two DNFs I've had and zero to Nico. I'll keep pushing and hopefully I'll come back stronger at the next race."