Grand Prix Notebook

display_e35f2226d3

Abu Dhabi

No title decider tension in the desert this time around, the big prizes long concluded. But a third consecutive victory for Nico Rosberg from his sixth consecutive pole completed a remarkable turnaround in form for the title runner-up. In the seasonal comparison between the two Mercedes drivers there was a very definite reset post-Singapore. In that race, it will be recalled, the Mercs were bizarrely uncompetitive, with a net pace swing of more than two seconds. The clues as to why Rosberg had set six consecutive poles since, and Lewis Hamilton’s dominance had evaporated, lies within what happened at Singapore. And the root of that goes back to the tyre blow-outs at Spa for Rosberg and Sebastian Vettel. The origin of Rosberg’s late-season dominance goes back to his left-rear Pirelli exploding that Friday afternoon in Belgium, just short of Blanchimont corner.

When Pirelli upped the minimum pressures in response to the Spa failures, it impacted fundamentally upon the Mercedes W06’s set-up – something that was not realised at the unconventional all-out speed demands of Monza but only in the aftermath of the following Singapore. “We were running the car totally wrong for the new tyre pressures,” says the team’s technical director Paddy Lowe. “The tyres were not in the right temperature window because we didn’t have the set-up where it needed to be. In terms of ride height, toes, cambers, aero balance – almost everything!” 

Between Singapore and Suzuka the W06’s sweet spot had to be found all over again in response to the new challenges posed by the revised tyre pressures. Even if the componentry remained just as it had been, the car was quite different in its feel and characteristics from Japan onwards as its baseline set-up had been so radically altered. This was to do with weight transference and getting front tyres that had effectively been made less grippy to load up quickly enough. This all came at a time when Hamilton’s third title was little more than a formality after a season in which he had totally dominated Rosberg and it would be accurate to say that Hamilton paid significantly less attention to understanding the newly configured car than the more motivated Rosberg – who put in the hours on the simulator and in discussion with the engineering staff. It would also probably be fair to say that the new traits of the car – a less aggressively grippy front end, primarily – had less effect on Rosberg’s natural driving style than Hamilton’s. 

In the 13 races up to and including Singapore Hamilton had outqualified Rosberg 12 times. Even on the one occasion he’d failed to do so, his tyres for the final Q3 run had been left in their blankets too long. In the six races since Singapore, Rosberg was the faster qualifier every time. It really was quite black and white – and the timing meant the trend just fed on itself. While Hamilton was partying and attending promotional events as the new world champion post-Austin, Rosberg continued to fine-hone his understanding of the car.  

Coming in to the Abu Dhabi weekend Hamilton had resolved to do something. The quick direction changes required through the tight twists of the final sector of the Yas Marina circuit had always been his personal territory through the years. But in a car with a front end he felt wasn’t going to be responsive enough for him to use that advantage, he made what he felt would be a crucial change, substituting the new heave spring that sits transversely across the front of the Merc’s suspension for an older-spec unit.

The heave spring controls the stiffness of the car when both sides are compressed together under braking. But Hamilton suspected the new heave spring was actually working too well in this. He wanted a bit more weight transfer onto the front, so the tyre was more squished as he turned in still on the brakes, getting the car to rotate quicker. He likes his cars to be stiff across the front, often to the extent that his inner front wheel waves in the air into a slow corner. Having the outer wheel briefly taking 100 per cent of the front cornering load theoretically gives less total grip through the corner but it can also give better initial response on turn-in. The tyre loads up more quickly and does not have the counter-effect of the unfavourable camber of the inside wheel working against that response. This effect will have been dulled when Pirelli reduced the permitted maximum camber at the same time as it increased the pressures. So Hamilton wanted to mitigate against those dulled responses by having the tyre more squished even before he began turning. Hence the less powerful heave spring. 

It sort of worked for him, but not consistently so. The car would occasionally ground out at the front, causing a front tyre to lock – particularly at the end of the back straight into the tight Turn 11, the beginning of sector three. The solution to having the weight transfer he wanted without the grounding out would have been to have increased the front ride height – but that would impose an aerodynamic penalty, especially through the fast turns of the first two sectors. Caught in a set-up cul-de-sac, he nonetheless stuck with it, trying to avoid over-using the brakes in the critical places. But in the end, it backfired on him – he was slower than Rosberg in qualifying by more than three-and-a-half tenths and most of that loss was in the final sector. “It was all about experimenting with the set-up,” he explained afterwards.
“I tried to claw something back – but it ended up hurting me more.”

The effect of the car’s post-Singapore traits are less significant to Hamilton in the race than in qualifying, as the tyre wear is forever changing the balance anyway, allowing Hamilton’s improvisation to keep him in play. But the super-soft quickly grained its fronts on everyone’s car here – and more so on Hamilton’s than Rosberg’s. So once Nico had won the start, he was able to build a useful lead before the first stops. Onto the more durable prime tyre though, Hamilton was faster – and ate steadily into the earlier deficit he’d incurred. Rosberg pushed harder in response – and damaged his front tyres. This gave the Mercedes strategists a dilemma, for the ideal strategies of the two drivers were now different. Rosberg needed to be rid of this set of tyres sooner than Hamilton, but not so soon that he left himself too many laps to do in the final stint. Meantime, Hamilton was eating into his lead and was almost into the DRS zone by the time Rosberg was called in. 

Hamilton was left out there for a further 10 laps, the idea being that he’d come out for the final stint on tyres that would be that much newer than Rosberg’s and therefore almost 1sec quicker. He gained for a while but just didn’t quite have the pace to make it work. He finished 8sec down – and not all that far clear of the Ferrari of Kimi Räikkönen who, for once, had enjoyed a clean, straightforward weekend. It was team-mate Vettel’s turn to be in the wars, failing to make it out of Q1 after a pitwall blunder. He came through to finish fourth.          

“I don’t think any of this set-up change stuff will be relevant next year,” said a Mercedes man. “The new car will be totally different.”

“Next year can come tomorrow for me,” said the winner, in what sounded suspiciously like fighting talk.