DANIEL Ricciardo says on-board video from Ferrari and Mercedes racing around Melbourne Park have made it agonisingly clear what his team's biggest weakness is.
Speaking ahead of this weekend's Chinese Grand Prix, Ricciardo says the videos of his F1 rivals in the championship-opener clearly shows Red Bull is struggling with rear downforce which has created grip issues on his back tyres.
Red Bull's rear downforce issues are so massive, Ricciardo says his team's weakness can be clearly seen when compared to his biggest rivals.
Ricciardo's Australian Grand Prix was a disaster following his crash in qualifying and a grid penalty and his eventual retirement in the race after just 25 laps.
His teammate Max Verstappen finished fifth.
It comes after a string of performance and reliability issues surfaced for Red Bull during pre-season testing.
The have clearly slipped down the F1 pecking order behind Ferrari and Mercedes.
"At the moment, we don't have enough rear grip - so downforce basically," Ricciardo said in Shanghai.
"To be honest, I don't know if it is we don't have enough or we haven't set the car up in the right way.
"I still feel that we haven't got the most out of the downforce.
"Melbourne, if I watch some onboards of Ferrari or Mercedes, it looks like they have more rear grip than us - so probably we don't have as much as them, period.
"I don't think we have understood it well enough yet to get the most out of it with set-up and ride heights, that sort of thing.
"I say we probably haven't found the right set-up but we've had enough time now, so I'd say we're still lacking and I would say it's a bit of overall downforce.
"At least for me as a driver that's what I feel for now and when I watch the onboards that's what I see, but more than that I'm not sure.
"Whether it's geometry and that of suspension, that's probably beyond me, but as a driver I feel that the rear could be stronger."
He said the biggest shock came when he studied onboard video of Ferrari's Kimi Riakkonen.
"For me and probably Max as well, we just felt that looking at Ferrari and Mercedes, we couldn't attack the corner as much because they just seem more planted on the rear," he said.
"Even on the high speed, we can kind of match them, but I feel we are like this more than they are.
"There was an onboard from one of Kimi's best laps from testing, and Turn 3, I think the top teams are doing Turn 3 full [throttle], and he did it - and he didn't even use all the track.
"He didn't let the car run out to the edge so, wow, he has got some downforce.
"I think it is something we knew from early on, that that is an area we have to work on now."
It came as Verstappen also opened up on Red Bull's early season struggles, in an interview with Skysports.com.
In a Sky Sports investigation into Red Bull's issues, Verstappen revealed Red Bull is up to a second-per-lap slower than Ferrari and Mercedes.
Despite pre-season expectations F1's new rules refresh, which put more emphasis on aerodynamic performance, would suit Red Bull, the former world champions were peripheral players at the season-opening Australian GP and are expected to fall further behind the leaders at this weekend's engine-centric Chinese GP.
But rather than blame Renault, who have borne the brunt of criticism for Red Bull's fall from dominance since the start of F1's hybrid engine era three years ago, Verstappen has admitted the team have their own car issues to resolve too.
"We have to improve," Verstappen said.
"We are working hard to get new parts to the car so we can get closer to the top two teams. Behind us is a big gap. In Melbourne l could have done two pit-stops and still finished in the same position."
WHAT'S THE DEAL WITH RB13?
HANDLING difficulties were a consistent feature of Verstappen and teammate Ricciardo's weekends in Melbourne, with Red Bull yet to find a consistent balance for the drivers to attack the track with confidence.
Ricciardo's uncharacteristic crash in qualifying, when he was pushing in an attempt to make up for the RB13's performance shortfall, appeared to highlight the car's 'knife-edge' handling.
"It's tricky," Verstappen told Sky F1.
"We are still finding out everything, it's not an easy fix as you know.
"We shouldn't make it too dramatic, we just need to find a good balance on the car from high-speed to low-speed so we are working hard to get new parts here for that to make that balance off-set a bit closer to each other.
"Then it should already be a big step forward, then we need more horsepower as well."
HAS F1'S SUSPENSION RULING HURT RED BULL?
THE FIA's pre-season clampdown on 'trick' suspension systems was thought to be directly aimed at Red Bull and Mercedes, but both teams have downplayed the significance of the decision.
"We haven't changed the suspension, it was exactly the same as in winter testing," Verstappen said.
However, the Dutchman did confirm the now-banned systems had been a development path the team had been considering and many in the paddock have suggested the RB13's handling imbalance may be linked to the crackdown.?
IS THE RENAULT ENGINE GOOD ENOUGH?
REPEAT reliability problems afflicted all three Renault-powered teams in winter testing, and although the French manufacturer introduced some fixes for Australia, issues with the MGU-K meant they are still having to run last year's heavier unit in the opening rounds.
Team adviser Helmut Marko told Austria's Salzburger Nachrichten this week: "A big [power unit] update from Renault is only planned for Canada but we will have a version that is slightly lighter and can be driven in a higher mode for a longer time.
"This makes us optimistic that we might be able to take the lead by Austria."
Verstappen said: "We are also struggling on the straights so we cannot say the chassis is really, really bad or anything, it's just a bit out of balance at the moment but we are working really hard and we will have some new parts here which will help us, then we will be closer."
WHEN WILL RED BULL CHALLENGE?
EVEN if long straights of Shanghai prove prohibitive to an immediate response to their two chief rivals' early 2017 advantage, there appears no outward signs of panic that Red Bull are poised to again be left behind at the start of a new rules era.
"In general, Melbourne was never a great track for Red Bull," Verstappen said.
"Last year they were 1.8 seconds off [pole] and we still managed to finish second in the championship.
"There is no reason to stress out. It was not an ideal start, it's not where we want to be, but we try to change it as quickly as we can."
The big question is how quickly they can turn the Renault-powered RB13 into a victory-contending car so they keep in championship touch with Ferrari and Mercedes before it is too late.
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