Morning report: Mercedes hit gearbox trouble on Day 1 of testing as Ricciardo puts McLaren fastest

Daniel Ricciardo set the benchmark time for McLaren on the opening morning of pre-season testing in Bahrain, while reigning champions Mercedes managed just a handful of laps as a gearbox issue kept Valtteri Bottas in the garage for most of the session.

McLaren hit the ground running as new recruit Ricciardo set a fastest lap of 1m32.203s, which was just 0.028s faster than runner-up Pierre Gasly’s best effort for AlphaTauri, as the teams got their first running of the test under way. Gasly managed the highest tally with 74 laps to his name by the lunch break at 1400 local time, with his rookie team mate Yuki Tsunoda set to take over from him in the afternoon.

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Max Verstappen, in the new Red Bull RB16B, looked more comfortable than the equivalent test last year, despite a small spin at Turn 2 early on. His lap of 1m32.565s briefly topped the timesheets one hour into the session, before Ricciardo rallied to go fastest.

But it was a very difficult session for the reigning champions. Forty-five minutes after the pitlane opened, black screens were erected in front of the Mercedes garage as Bottas limped his W12 back in, with just a single installation lap under his belt. The team were forced to replace the gearbox on the car, and the engine was fired up again with 40 minutes remaining - Bottas adding five laps to his total for a final position of 10th quickest. Lewis Hamilton will take over driving duties for the afternoon.

Alpine’s Esteban Ocon was the last driver within a second of Ricciardo, fourth overall. The returning Fernando Alonso is not due in the car until tomorrow.

Ferrari had a steady start to testing with Charles Leclerc finishing fifth-fastest, 1.039s off the pace. Though with 10 minutes remaining, he suffered a suspected power unit issue and brought out a red flag as marshals recovered his car on the entry to Turn 4. The session resumed with just over three minutes left.

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Behind Leclerc in the lap times was former Ferrari driver Kimi Raikkonen – who emerged first in the session – for Alfa Romeo while another ex-Ferrari alumnus, Sebastian Vettel, put 51 laps on the board for his new squad Aston Martin in the racing green AMR21. Neither Raikkonen nor Vettel will drive in the afternoon with their respective team mates, Antonio Giovinazzi and Lance Stroll, taking over.

Williams test driver Roy Nissany has day one to himself in the FW43B and managed 39 laps to finish eighth fastest overall. Nicholas Latifi will drive on Saturday, with George Russell taking Sunday.

Mick Schumacher returned his famous surname to the F1 timesheets for the first time in eight years but a gearbox issue meant he managed just 15 laps for new employers Haas, who officially unveiled their VF-21 ahead of the session. He hands over to team mate Nikita Mazepin for the afternoon.

GALLERY: Top shots from Day 1 of 2021 pre-season testing in Bahrain

While McLaren will be delighted with their morning showing, with Lando Norris to enter the fray in the afternoon session, Mercedes will be worried by their gearbox problem that left Bottas garage-bound.

Another lingering worry for all is the threat of a sandstorm from the surrounding Sakhir desert, with wind picking up around the track as the morning running came to a close. There are just two-and-a-half days of testing left, so every second counts.

Stay tuned to F1.com for live coverage, instant reaction and more from pre-season testing at the Bahrain International Circuit.