On the boiling austrian tarmac Mercedes seems to struggle with rear instability as, at the same time, cause and consequence of tyres overheating.
While the overall flying-lap performance by the Stuttgart team looks beatable but still very competitive, in the garage there are concerns on the race pace.
Almost every car during the qualifying simulation improved its lap time on the second run, after two cool-down laps in a row. Almost every car but Mercedes. Indeed hot temperatures in Austria forced the teams into an extra effort in order to get into the best tyre-window, with pressures massively increasing.
From the TV cameras and the team radio we realized how much the Silver Arrows are fighting against rear-end instability in particular in turn one and turn three. This instability is caused -beside a not-so-perfect balance of the car- by overheating that gives the rear tyre a floating feeling both in the changes of direction and when the driver goes on the trottle at the exit of the corners.
This extra spinning provides the tyres with even more heat, which increases the pressures and generates a negative loop.
We've heard Valtteri Bottas and Lewis Hamilton's complains but the most clear proof of troubles were given by the mechanics.
The rule book in fact provides guidelines on pressure levels that cannot be exceeded in any way. In the Mercedes garage therefore, before the car left the pitlane, the tyre blankets were left open to dissipate some of the heat.
Moreover, cold air was blown into the rear wheels in order to cool them down and consequently bring the pressures down to the right window.
If on a single flying lap that may not affect the performance of the car, the concerns are on tyre degradation during the race and in a overtaking-friendly track as the Red Bull Ring it might be difficult to manage without losing positions.
Other problems may also come up during the Q1 session, with twenty cars traffic-jamming the shortest circuit on the calendar by doing two cool down laps between a run and the other.