Lewis Hamilton was left “a bit sore” after his Mercedes struggled with bouncing on the straights in Friday practice at the Azerbaijan Grand Prix.

Team-mate George Russell said the new rules needed to be re-thought.

“I don’t think it’s right to run like this for the next four years or whatever we’ve got,” Russell said.

“Conversations are going to be needed because everybody is in the same boat.”

Bouncing on the straights – caused by a disruption to the car’s underbody airflow – has affected most teams to some degree this year following the introduction of new rules aimed at closing up the field and making overtaking easier.

These have changed the way the cars’ aerodynamics work and led to the bouncing problem, with which Mercedes are struggling more than most.

The world champions hoped they had got on top of it with some changes made for the Spanish Grand Prix two races ago but it has returned on Baku’s long pit straight this weekend, which features a series of kinks taken flat out.

Russell, a director of the Grand Prix Drivers’ Association, said: “Now the car is running so close to the ground, it’s crazy through those high-speed corners.

“The car is fully bottoming out and I think it’s the same for everybody and it’s really not comfortable to drive. I don’t know what the future holds for this era of cars but I can’t see us being able to [continue like this].”

Both Ferraris also appeared to be struggling with bouncing on the straights.

No other driver complained to the same extent as the Mercedes pair, although Ferrari’s Carlos Sainz admitted he, too, was struggling with the problem, which is also known as “porpoising”.

Sainz said: “It is certainly something I am looking into because for some reason today I struggled a lot with this phenomenon which hasn’t been there the last few races and it looked particularly bad on my side of the garage.

“It’s something I need to dig into with the engineers. It was taking out a bit of confidence on the straights and the braking.”

F1 managing director Ross Brawn – who was central to the introduction of the new rules, which have changed the way the aerodynamics of the cars work this year with the aim of closing up the field and making overtaking easier – has previously dismissed similar comments by Russell, saying he was only really interested in the thoughts of drivers at the front of the field.

Following changes to F1’s structure, the team under Brawn who developed the rules have been transferred and now work for governing body the FIA.

Russell was the fastest Mercedes driver, in seventh place and 1.3 seconds off pace-setter Charles Leclerc of Ferrari, with Hamilton a further 0.3secs behind.

Hamilton said: “We tried something experimental on my car and it didn’t feel that great to be honest. But at least we tried it and got data on it. We will go through it and hopefully for tomorrow we will probably revert back to what we changed.

“1.6secs or 1.3secs or whatever it is; that’s a long way away. A lot of it is on the straights.”

Ferrari and Red Bull close again

Leclerc ended the day 0.248secs quicker than Monaco Grand Prix winner Sergio Perez’s Red Bull and the Ferrari driver said he had had “a good Friday”.

Leclerc’s title rival Max Verstappen was a further 0.108secs adrift. Fernando Alonso – whose Alpine features a major aerodynamic upgrade this weekend – was fourth quickest, pipping the second Ferrari of Carlos Sainz.

Leclerc said that the nature of the sessions meant understanding the true performance picture was difficult.

“I think it will be [a hard fight at the top],” Leclerc said. “We have improved quite a lot from P1 to P2 but there is still another step we need to do tomorrow.

“I also feel like in P2 nobody really put a lap in – neither did we, but Max and Carlos didn’t actually improve on the softs so there are still quite a lot of question marks.

“The positives to take from today is that the degradation was good and the race pace was very strong, so that is good.”

Leclerc has seen a 46-point lead over Verstappen after three races this season turn into a nine-point deficit after four consecutive Red Bull wins and a series of problems for Ferrari.

But he said he believed he would be able to regain the advantage as the season progressed.

“If we do everything perfect, I am confident we will take [the lead] back at one point,” Leclerc said.

On race pace, Ferrari and Red Bull looked closely matched in Baku.

Red Bull had looked the team to beat in the first session, in which Perez was fastest and when he and Verstappen were clearly faster on the straights – a key factor on a track where they are so long and overtaking is relatively straightforward.

But Ferrari’s deficit on the straights reduced in the second session, and Leclerc moved into his customary position this season as the one-lap pace-setter.

Verstappen took to the track late at the start of the second session as Red Bull made repairs to his rear wing, after it was fluctuating when the DRS overtaking aid was open during the first session.

Later, his qualifying simulation runs were disrupted by traffic. And he managed to complete only two laps in race trim at the end of the session.

Nevertheless, Perez did appear the more comfortable Red Bull driver during the day, as Verstappen complained about understeer in the first session and then appeared to be struggling with a loose rear end early in the second.

As such, Perez appears set to continue his strong run of form, following his victory in Monaco last time out.

Perez said: “It was a good start to the day, P2 didn’t go as well as we would have liked. I think we probably took some wrong directions, or we were just exploring and we are not able to spot out our problems.

“But we have the data on both tyres on the long runs. Hopefully, we are able to put it all together for qualifying. I feel confident out there.”

Behind Sainz, Alpha Tauri’s Pierre Gasly was sixth quickest ahead of Russell, with the Frenchman’s team-mate Yuki Tsunoda eighth, from the second Alpine of Esteban Oco.n and McLaren’s Lando Norris.