Mechanics of Mercedes problems

[timbo]

I haven't seen before a car which was fast enough for pole loosing that much speed over the race.
Why does it happen?
The two variables which change are weight and longer stints.
Let's first look at stint length. Yesterday we've seen that Rosberg could lead for the length of first stint, and then it went wrong. We also seen that in Australia that they could run longer stints than many others at the first half of the race. Somehow it seems they suffer more as the race progresses -- and that happens gradually. If it's only tyre related problem, they would likely have reasonable pace after the pit-stop and then fall back. We've seen their drivers complaining about tyre deg, but then who doesn't complain?
Now weight -- looking at their qualifying pace and their results in races one may wonder whether their car is faster on fumes and just don't take full tank very well. But in such case we would likely see their relative pace improving towards the end of the race.
So what else should we look at?
I see a few things else:
1) fuel consumption
2) somehow they suffer more when running in traffic because they somehow have higher aero sensitivity?
3) maybe the performance of their suspension degrades over time?
4) they have VERY effective DRS (but this one is easy to see, we should look at the speed-trap results with and without it)?

[thepowerofnone]

I will just shoot down 1) and 3) now - fuel consumption will be governed by their engine and their aerodynamics, and they aren't the only guys to use the Mercedes engine, its basically the same one that was in the McLaren last season when it was the quickest due to the development freeze on engines, and so its probably not that; as you say, they are very quick in a straight line so they clearly aren't carrying a whole lot more drag than most of the other cars, so its not that either. Ergo not 1).

3) the performance of their suspension will not degrade, if that was happening then it implies that during a race their suspension is slowly failing and no team would have that. Plus its very difficult to make carbon fibre wishbones and push/pull rods alter their stiffness without just failing.

Their problem is very clearly tyre degradation, they are hit by it much worse than probably any other team, just listening to Hamilton's radio yesterday you could hear his engineer repeatedly tell him to slow down to save tyres. How they solve that problem is another question, and Mercedes would pay you lots of money if you could give them an answer to that. That car has traditionally always been tough on its rear tyres so we will see what happens with its development, but if I had to guess I would say its not going to be an easy problem to fix.

[rjsa]

Wat I saw it NR was leading a train for most of the first stint. The minute he was out of the way FA just ran away from the whole pack.

They are just eating the tyres.

[autogyro]

I will hazard a guess for what it is worth.

The Merc suspension works brilliantly, it gives them a huge benefit in qualy.
However because it works so well it makes more use of the tyres which wear more.

You could reduce downforce to reduce tyre wear but this would probably lose to much traction and cornering potential.

There was mention of altering the cars set up to convert excess oversteer to understeer but this only moves the tyre wear to the front tyres.

It gave me a hint though.
The only other thing affecting rear tyre wear in a major way is the differential.

I think Merc needs to fit a better form of torque vectoring diff to balance traction across the drive axle.

Will they send the money now or later?

[pocketmoon]

I'll update this post later this evening with some links but the w03/w04 have both shown good pace in the latter half of races. There's one chart on f1fanatic from a race last year (I shall dig it up later) that had shumi absolutely flying after spending the 1st part of the race looking like a Mercedes train (with cars stacking up behind).

At the start you can overcome some lack of full-fuel pace but turning the dials up but you can't race like that without running out of fuel. Starting in P1/2 the team would have had both cars running as hot as possible to stay out in front and hope not to drop too many placed over the opening laps.

Some thought on top of your thoughts;

1) fuel consumption
Fuel isn't just used to turn the wheels now. The exhaust energy is being put to work for aero gains.

2) somehow they suffer more when running in traffic because they somehow have higher aero sensitivity?
When the front runners pull away the lads have clean air and still fall back.

3) maybe the performance of their suspension degrades over time?
or maybe it suffers on a full tank ?

4) they have VERY effective DRS (but this one is easy to see, we should look at the speed-trap results with and without it)?
Can we rule that one out ? In Barca they owned in Sector 3 (non drs, I think!)

I feel an evening of pouring over f1fanatic lap charts coming on

Rob.

[timbo]

Here is a comparison of Alonso's time (blue) with Rosberg's (red)

What seems strange to me is that Alonso exhibits very even pace which improves at every stop as it should be, because the car get's lighter and lighter.
Rosberg OTOH goes slower in the second stint than he was in first. There's little improvement on the third stint, and somehow he manages to improve his pace at end of the stint, and there's something stange going in the final stint as well.
It looks like his car didn't get lighter until the final stint .

[thepowerofnone]

His first stint was on the option, his second on the prime - that could account for the jump, although it would be a big jump, or he was told to push at the start then conserve when he went onto the primes?

[timbo]

The other question -- if they knew they have degradation problems, why 3 stops?

[monsi]

The Mercedes times look rather unstable. Alonso's look fairly predictable. I would speculate that Mercedes spent much of the time right on the edge, or just falling out, of a tyre operating window. Anyone know if their problem is insufficient or excessive heating of the tyre, and if so which ? Given that Jenson complained that a very slow formation lap caused his tyres to drop out of the window, I would guess that Mercedes are happier at lower temperatures, but it is a guess.

[marcush.]

The other question -- if they knew they have degradation problems, why 3 stops?

that´s the point here.Why would you try to stretch your tyres knowing you have more deg than all the others?
That´s completely counterintuitive .I would try to play the strength of my package not try to lean on the weaknesses.Is their gearbox or heat manegment at risk with one more stop?

[timbo]

thai´s the point here.Why would you try to stretch your tyres knowing you have more deg than all the others?
That´s completely counterintuitive .I would try to play the strength of my package not try to lean on the weaknesses.Is their gearbox or heat manegment at risk with one more stop?

And there's another oddity -- look at Rosberg's third stint -- at the end of it he could run pretty fast all of the sudden!

[pocketmoon]

What happened to Rosberg between laps 42 and 43? Did get get a message to "push" ? The four laps before his final pit jumped over 1.5s per lap quicker than he was doing lap 38 to 42 ?

(edit - Timbo beat me to it

[timbo]

What happened to Rosberg between laps 42 and 43? Did get get a message to "push" ? The four laps before his final pit jumped over 1.5s per lap quicker than he was doing lap 38 to 42 ?

(edit - Timbo beat me to it

And there's something similar happening before his second stop (to a smaller degree) and before the finish of the race. Maybe he was deliberately slow, and then was let to race?

[marcush.]

the second stint was showing deg from lap 18 till l22 maybe they feared more of the same in the later stints and paced themselves too much?

[DaveW]

For what it's worth here is the last sentence from an article by Jonathan Noble in Autosport:

The nature of the challenge of looking after tyres means cars that are more mechanically sympathetic like the Lotus and Ferrari are better equipped when it comes to being consistent in the races.