Given all the chatter about the Brawn's difficulty with getting and maintaining heat into their tires this year - I would like to hear from the forum about this issue. Where does it come from? Is it the basic weight and aero pressure distribution inherent in the design?
Is there a mechanical solution - such as, suspension setup geometry or do they have to start moving pivot points on the chassis?

Why is the Brawn design so stuck within this narrow range of tire temp parameter? As opposed to some other designs? And why haven't Brawn been able to deal with it over the course of the season?

Please enlighten....

Drivers. Rubens didn't have near the 'problems' Jenson did but as he was a somewhat distant 4th in the championship when Button started to lose relative pace, Rubens was ignored as a reference point.

Agreed that driver style and preferences have a huge impact on tire performance. But, in trying to understand the cause of this issue, especially with Brawn, it seems both JB and RB and F1 press are always talking about ambient temp and how much it affects the pace of the Brawn. Perhaps, one driver more than the other.. Still, you'd think Brawn would be attacking the cause of the issue. It seems like they're just stuck with it and at the mercy of the elements. HA!

I just want to understand the technical issue better and was hoping for some tech input....

During practice, if not during the race, the teams must have telemetry on swa and throttle and brake, so if one driver can get his tires to warm up and the other can't they should just look at the data and tell him what to do.

Or else it is all baloney and driver 1 can drive on cold tires and driver 2 can't. My money is on this, for instance one of the V8 drivers is brilliant on cold tires.

Basically it depends on how effectivly the car is using its tires. Use the tires more effectivly and there is less friction heat to keep the tires at working temperature.

Buttons 'softer' driving style is probably more affected by this than Barrichello.

Last year we saw the same thing with Ferrari vs. McLaren. Ferrari had troubles getting their tires up to temperature in qualifying and in the beginning of a stint, which meant they lost pace compared to the McLarens. But later in the stint Ferrari got their tires working, while the higher tire wear became an issue for the McLarens.

So, fundamentally there is nothing to be done mechanically or aerodynamically? It's all down to driving style and a specific driver's inability to adjust? I don't know about that... I've read that the Bridgestones have a startingly unreliable reaction from team to team and even from race to race on the same car.

I think these tires are screwed and Bridgestone has no incentive (competition) to worry about anything except their expense providing the teams.

Seems unfathomable that the likes of Brawn's technical team would have such inconsistant results without attacking the problem. They can't do anything about tires.

Everybody gets the same tyre, it is up to the team to get the best from them, level playing field from the tyre perspective.
It may be in the organiser's interest from a show perspective to have the tyres vary from event to event.

What kind of setup changes are used to control contact patch temp or carcass "whole tire" temp?

There are more knowledgeable people here than me but some things to think about.
There are several "heats" to think about: tread surface, carcas surface, air and sidewall.
To put heat into the tyre you need to "work" it. As the tyre rotates the bit going into the contact patch (and sidewall) flexes from round to flat and back again, this generates heat. A large contact patch will tend to flex more. The contact patch will transfer some heat to the track surface when in contact, how much? I don't know, will depend on track temperature. The contact patch size changes with dynamic cornerweight (weight transfer, spring, damper) and downforce. Number of "flexes" per minute (power) depends on speed and tyre diameter. How much it flexes depends on dynamic tyre stiffness. How much heat per flex depends on tyre construction and materials.
Slip angle generates heat, more angle gives more heat. Slip angle can be geometric (static toe, ackermann, bump/roll steer characteristics) and/or the slip angle used to generate the required force. Slip (longnitudinal) also generates heat ie braking and acceleration.
Lateral (scrub) movement generates heat, this depends on camber change with wheel movement and on the virtual swing arm length of the suspension. Caster change and suspension antis can give the tyre some longnitudinal flexing. Vertical wheel movement depends on dynamic and static roll, heave and pitch stiffness, roll inertia, pitch inertia, roll centre height, centre of gravity height, third spring etc.
Dynamic camber can affect the tyre heating.
Braking heats the wheel and therfore the tyre, the brake cooling air may affect the tyre.
The part of the tyre that is unloaded cools, this will depend on the airflow that the tyre sees.
Remember a large part of the tyre heat is ultimately provided by the engine.

gordmac - thanks. That's the kind of info I was searching for.

I think all who have contributed to this post have made valid arguments. Its interesting because we had a similar problem running a high powered single seater during testing last week - so with it fresh in my mind I thought I'd join the discussion.

We struggled in low ambient temperatures to get heat into the front tyres (by heat I am referring to carcass temperature). This causes a snow ball effect, because without the "operating" temperature in the tyre there is no grip, and without any grip you generate no temperature and so the cycle gets worse and worse. The problem was compounded by the high power output of the engine, which makes it very easy to generate rear tyre temperature.

It is no surprise that Jenson, who has a recognised smooth style, struggles when ambient temperatures are lower... but as Greg points out - this is a driver style thing and the team need to work with the driver to stimulate tyre temperature. The driver needs to work exceptionally hard on the fronts, because one blip of the throttle on his outlap and he's probably got the rears "in".

From a setup perspective making the tyre work harder increases temperature, and this can be achieved by increasing heave or roll stiffness, increasing cambers or increasing bump damping to name a few. Tyre pressure is a funny one, because higher pressure tends to stimulate surface temperature, lower pressure tends to stimulate sidewall temperature. Its up to the engineer to pick which side of the mountain he is on! The key thing is that the team looks at the information they have available: tyre internal pressures, surface temps (IR sensors), carcass temps (from a pyrometer) and their "spreads" across the tyre. Each tyre will need a different set of operating conditions but its key to keeping them there.

I would summarise by saying that it appears that Brawn have done too good a job preserving their tyres, which in low ambient conditions makes it hard to get into the working window. Remember at Monaco when Jenson managed his stint on the super-soft tyres to perfection whilst Vettel struggled? Thats when the driver and team got it right; but when the temperature drops their strength (at Monaco) becomes their achilles heel.

Comments welcomed!

All good stuff, but nobody appears to have mentioned tyre construction.

If, for example, the front tyre vertical dynamic stiffness is increased (by construction) from a good starting point, then the front tyres will absorb less heat. Similarly, if the rear tyre vertical stiffness is decreased (again by construction), then they will absorb more heat. Taken far enough, the front tyres will not reach operating temperature before the rear tyres "go off". The solution for such a senario is to move the centre of gravity & centre of pressure forward, but this will reduce traction. The compromise is to move the centres of gravity & pressure just far enough to to manipulate tyre temperatures by the required amount. The result is a vehicle with a very narrow operating window, one that will change with any minor shift in ambient or track conditions, leading to a highly variable (& unpredictable) performance. Far fetched?

Logic would suggest that the rear tyres of a mid-engined aero vehicle should have the greater vertical stiffness. Some example (rear/front) vertical dynamic stiffness ratios:

F3: 1.24
LMP: 1.1 - 1.3
RWS: 1.3
GP2: 1.2

F1 (2009): 0.91

No more to be said, really, except to sympathize with those who have to try & make an F1 vehicle "work" consistently.

ddub and DaveW - thanks, starting to make more sense to me now.

Dave's point about centers of gravity and aero pressure really puts tire construction in new perspective. I'll bet when tire manu's have brand competition, they are more likely to change carcass construction, front and rear, for different types of tracks - high speed vs low speed corners. Bridgestone doesn't have to worry about that, now.

I might, perhaps, have added that set-up decisions are not helped by a couple of the more crazy F1 regulations. Set-ups have to accommodate two tyre compounds, and must be chosen with the help of data from an "evolving" track, since no significant changes are permitted after the start of qualification.

p.s. Michelin (2005) : 1.32, Bridgestone (2005) : 0.91. How many poles/races did Bridgestone runners win in 2005?