Why Mercedes has been so inconsistent in 2017

Seven races into the 2017 season and we still don't have a clear picture of whether Mercedes or Ferrari has the upper hand in the championship fight.

While that's positive for the excitement of the battle, we need a clean weekend for both so we could actually see who is responding best to the pressure of either staying up front or catching up.

Both teams will surely go back to base still wondering how aggressive their development plans need to be, and how quickly upgrades need to be put into place.

What we did see in Canada was proof, if it was needed, that if you give Lewis Hamilton the tools to do the job he will deliver the results.

Both of his qualifying laps were mega, but so was Vettel's first attempt. Vettel just got that little bit too hungry on his second lap to pose a real threat.

But once Vettel had suffered the front-wing damage on the first lap, it was basically a case of minimising the losses as best he could.

He did that well, but wouldn't it have been good to see a straightforward battle between the two of them at a track where, because of its long straights, overtaking is difficult but still possible? Fingers crossed we'll get this battle soon.

In my opinion, the Ferrari is the better chassis and the Mercedes has the better engine - when it can turn the knob up for qualifying.

But saying that, Mercedes has certainly made progress on the chassis front since Monte Carlo. So why did this happen?

I'm pretty sure some of it was because of the nature of the Montreal circuit compared to the nature of Monte Carlo.

Mercedes personnel, and especially Valtteri Bottas, have been talking about the small working window that the car gives them, and how easy it is to miss that working window.

If that happens, it's hard to get the tyre warm-up required, making it, in effect, a double whammy.

This situation normally comes from a peaky aero map. In other words, the downforce produced by the underfloor and diffuser is critical to the car's ride height.

It's easy to ask 'why does Mercedes suffer from that this year when it's dominated since 2014?', but the reason is quite simple.

The regulations for 2017 allow for much more downforce to be produced by the underfloor and diffuser, perhaps twice last year's amount, so it's a new learning curve.

To explain what the aero map is all about, a car's downforce-producing ability is all about its ride height change.

The front suspension set-up of these cars is a lot stiffer than the rear. If it was linear, it would probably be at a ratio of around 3:1, so for 10mm of front ride height change, the rear would move around 30mm.

During this movement, which happens as the car increases speed and the downforce pushes it towards the ground, it is important to keep a stable centre of pressure. This is the point where all the aerodynamic forces join up and push on the car.

If some part of the diffuser or underfloor is suffering from an aerodynamic stall or is being affected by inconsistent airflow coming off some of the components upstream - such as the front wing or bargeboards - then the centre of pressure will shift around and make the car inconsistent. This then reduces the driver's ability to push to the maximum.

To overcome this sort of a problem the teams will try to come up with a set-up that will stop the car from getting into that critical area.

But this will mean a compromise in overall performance and, as I said above, this compromise can be circuit specific.

If we look at Monaco, the circuit requirements are: low-speed mechanical grip, good suspension compliance for the differing road cambers, good traction and maximum downforce without worrying about drag levels.

These requirements will benefit from a softer front and rear suspension set-up and as I said in my column after Monaco I believed the Mercedes was moving around a lot more than the Ferrari so any underfloor airflow separation problems will be more pronounced.

If we look at Montreal, the circuit requirements are: heavy braking, quick change of direction, good traction and lower drag, which in turn comes with lower downforce.

All of these requirements will benefit from running a stiffer front suspension set-up and also, because of the reduced downforce requirement, from not working the front wing as close to its aerodynamic limit.

These different circuit set-up requirements, combined with the minimum tyre pressures that were allowed in Monaco (compared to the higher minimums the teams ran in Montreal) means that the car's movement from aerodynamic loads in Canada would have been reduced dramatically.

To explain what the tyre pressures do to the car, one psi alters the tyre stiffness by about 50lbs/in. Going lower makes it softer and gives a bigger tyre contact patch, offering more grip - especially in low-speed corners. In Monaco, the minimum pressure was 17/16.5psi front/rear and in Montreal it was 20/18.5psi.

These lower pressures compared to Montreal would be very important for the low corner speeds in Monaco, but for the front suspension it would mean roughly a 10% reduction in overall front vertical stiffness.

For the rear it would be a 20% reduction in overall rear vertical stiffness.

So although there is a grip benefit overall, it can easily bring with it other problems like more car movement.

Higher tyre pressures, which were mandatory in Montreal because of its long fast straights, increase the tyre stiffness and, in turn, reduce the car's low-speed grip levels.

But, more importantly, they reduce the car's vertical movement, which for Mercedes might just have been a good thing.

Will Mercedes suffer from its Monaco problems again? Probably, but I am sure it will trawl through the mountains of data comparing Monaco to Montreal and will very soon have developments in place to eradicate any potential aerodynamic airflow separation problems.

IN DEFENCE OF PEREZ

Looking back to the race itself, the other notable thing that happened was near the end when the two 'Pink Panther' Force Indias were together and challenging Daniel Ricciardo's Red Bull for third.

Sergio Perez had been snapping at his heels for a while, but couldn't manage to launch an attack. So when Esteban Ocon caught them both on fresher rubber, he wanted to swap places with Perez to have a go. The commentators said this should happen, but I disagree.

You have got to remember that Force India is a small team compared to the might of Red Bull. It was running fourth and fifth and Perez was hoping for a Ricciardo mistake that would get him onto the final step of the podium.

Perez has done a lot for Force India, which picked him up after the tough year at McLaren that almost broke him, and he deserved the opportunity to go for the podium when it's there to be had.

Ocon is the new kid on the block, he is doing a fantastic job and as he said after the race, his time will come.

Sebastian Vettel, in the Ferrari on fresh ultra-soft tyres, was always going to pass the Force Indias if he could clear Kimi Raikkonen. And there was very little chance of Ocon mounting a serious challenge to Ricciardo as, after all, he wasn't actually pushing his nose in on Perez.

Personally, I would have instructed Ocon to drop back a second to allow Perez to attack Ricciardo without having to keep one eye in his rear view mirrors. This way, he could also have been rear gunner for Perez and, with his slightly better tyres, he could have held Vettel up for a couple more laps.

As it was, they all ended up fighting for the same part of the track at the same time and in the end both Force Indias lost out to the Ferrari and finished fifth and sixth.

But remember that the Ferrari is a car that is challenging for the world championships and not in direct battle with Force India. So it was a still a great result.

THE RETURN OF THE RAFT RACE

With the backing of F1's new owner, the famous inter-team raft race in the Olympic rowing basin returned last weekend.

When it was first a fixture of the Canadian Grand Prix weekend, we at Jordan knew nothing about it until we turned up for the race in 1991.

In our first season we were a bit naive about the requirements of F1.

When we arrived at the first race, the United States GP in Phoneix, and went out into the pitlane all the teams had what was called a 'prat perch'. This is where the race strategist, engineers and other attention-seekers all sit during practice and the race.

We didn't have one, but as Phoenix is scorching hot I thought we had better do something about it.

I called a friend of mine, Craig Tavaner, who I had worked with at Galles in Indycar. He lived in Phoenix, so came around to see me and we measured up for our very own prat perch.

It arrived on Saturday and was made from two-inch diameter aluminium scaffold poles, a tent-cover top and a plywood desk area with no seats. It was very adequate and probably as cheap a prat perch as there ever was in the F1 pitlane.

When we arrived in Montreal we found out about the boat race and as a team that liked a bit of fun we decided it was just our cup of tea.

In those days, you had to make the raft from what you brought with you in the freight (Sauber's 1994 attempt is pictured) and Paul Thompson, our then-head of R&D (there was only one person in R&D) and Phil Howell set about building a boat.

We looked around, and as the prat perch was made from these scaffold poles and had clips holding it together, we took it to pieces and reassembled it slightly differently to hold some very large plastic part trays.

That night, a few polystyrene circuit marker boards may also have gone missing, and with the aid of a saw they were made to fit the parts trays to help with the floatation.

Andy Stevenson, now racing director for Force India, and Nick Burrows who was Bertrand Gachot's number one mechanic, were entrusted with our trusty steed.

They paddled like Olympians and Jordan took the top step on the podium!

It was an omen because we also went on to score our first points in F1 with a fine fourth and fifth for Andrea de Cesaris and Bertrand Gachot!

And just to prove that if it isn't broke don't fix it, we used the same piece of kit as a prat perch the next year and did exactly the same thing when it came to the boat race in Canada.

We won again, as we did every year until people got bored of organising it!

In 1992, we won it while having a miserable season with a Yamaha engine that was more boat anchor than F1 engine.

It was a bit like what McLaren is going through right now with Honda. Plenty of promises, but very few developments.

Even when we did get an engine with more power, it normally blew up - sometimes before it even got out of the garage.

McLaren won the boat race this year, and look what happened in the race...

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