Pirelli's decision to change its Formula 1 tires from the Canadian Grand Prix onward will potentially have a far-reaching effect.
Tires are an integral part of the car's design, affecting the aerodynamics and the suspension. With changes to the construction moving back towards the 2012 tire specification, married to the current compounds, teams will be heading back to their computer screens to re-optimize their cars around the modified tires.
Tires have a big impact on the airflow around the car, not only because of their size but also because of the sidewall profile and the way it deforms.
Traditionally, the impact has been more critical around the front tires, as with the front wing in close proximity to the tire, small changes in this area have a compound effect downstream. But with the increased importance of air and exhaust flow around the rear tires in the current generation of grand prix cars, there will also be implications for the rear end.
For wind tunnel testing, Pirelli supplies 60 percent scale tires, which accurately reflect the deformation of the tire. Teams should be able to revert to the 2012 wind tunnel tires for aero testing.
Because of the change, teams will need to produce new versions of wings, endplates, floors and brake ducts.
Teams are provided with Pacejka models of the physical properties of the tires by Pirelli, allowing their accurate representation in simulations. As with the wind tunnel tires, it will be a case of reverting to known 2012 tire data.
From this base, teams can look at revising their spring, damper and linking rates to account for the difference between the new and old construction.
Additionally, the suspension geometry will need revising to get the camber gains and the roll-center location that work with the older tires. This requires revised suspension elements at the front and rear, necessitating new patterns, molds and wishbones to be made – which is a significant investment mid-season.
Teams are faced with a large, but not insurmountable, challenge to adapt to the new tires given the experience gained last year. But it is a drain on resources for teams already stretched to develop new cars for the 2014 regulations.
The combination of the old tire construction and new compounds will also be untested by teams going into the Canadian GP, which is quickly followed by some punishing, fast-flowing European tracks with unpredictable weather. So any steps to stabilize the racing with these tires could be offset by the effort required to adapt to them.