Mercedes admitted they need to make "fundamental improvements" to their car after Friday practice sessions which left Lewis Hamilton feeling "sore".
The Silver Arrows were once again some way off the pace compared to the likes of Red Bull and Ferrari, as they continue to be plagued by porpoising issues. The high-speed bouncing is particularly bad at Baku, especially along the long and bumpy main straight.
A lack of balance in his car and set-up issues have left Hamilton 75 points adrift of championship leader Max Verstappen after only seven races, Improvements later in the season may see him close that gap, but the Briton is already effectively out of the title race.
After finishing Friday practice more than a second and a half slower than pace-setter Charles Leclerc, he had extra reason to be in a bad mood as all the porpoising had left him in pain. "Bouncing," was his simple reply when asked by Sky Sports F1 what the hardest part of the day had been.
"I'll get by. I'm a bit sore but yeah. We're hitting some serious speeds at the end of the straight here and it's bottoming out. We tried something experimental on my car and it didn't feel that great to be honest. But least we tried it and got some data on it and now we'll go through it.
"We'll probably revert to the original set up tomorrow. I can't tell you one specific area which is costing us the 1.3 or 1.6 secs difference to the front, a lot of it seems to be on the straight but we need to get our heads down tonight and find solutions."
Mercedes' trackside engineering director Andrew Shovlin had echoed that call for a hard night's graft from the team, and gave a glum assessment of the problem which he feels will force them to go back to basics. "The balance isn't a major issue but we're lacking grip in the corners and the ride on the straights is uncomfortable for the drivers, so we need to improve that overnight," he said.
"Our straight-line speed also isn't great but some of that will be due to us hitting the ground on the straights. We did have some new parts on the car today, so we'll review whether those were contributing to our issues. Overall, we're not in a good position and it's one where we need to be looking for some fundamental improvements rather than a case of fine tuning."
