Ferrari front pull-rod
When the rumour of front pull-rod was circulated during the pre-season, it didn't seem realistic that this could work. At the rear the low position of the gearbox makes the pull-rod geometry easy to achieve, but at the front the chassis is some 30cm in the air; this places the pull-rod nearly horizontally.
Intuitively, this looks like the rod would barely move the rocker as the wheel rises. But the pull-rod actually operates by creating a triangle with the wishbone, so in actual fact it's the angle between the wishbone and pull-rod that creates the displacement. When comparing Ferrari's pull-rod geometry to a push-rod, the relative angles are the same and therefore both operate the rocker equally efficiently.
So clearly Ferrari has found a solution that has similar geometry to the push-rod that went before it. So it's unlikely that they have gone this route for improvement in operating suspension. The most likely benefit will be aerodynamics and packaging.
Aerodynamics may seem an odd benefit; it's true the pull-rod can be thinner, which might create a small benefit, but it's likely the near horizontal position of the pull-rod is the key to the real benefit. Teams already shape their wishbones to manage airflow off the front wing. Within the tight rules, quite a lot of aero effect is achieved with the wishbones. As the pull-rod is horizontal compared to the angled push-rod, it can be more effective in altering the airflow over the car.
Also the packaging around the front brake ducts becomes easier compared to push-rod, as a pull-rod no longer passes straight through the area where the cooling scoop is fitted. This creates more freedom for the designer to shape the brake ducts.
With the F2012's nose and chassis being raised to their maximum, the centre of gravity of the car will be also be raised. As pull-rod effectively turns the push-rod system upside down, the weight of the rockers, torsion bars and other mechanical parts are now placed at the bottom of the nose, rather than the top. This helps lower the centre of gravity a little, to offset the new nose design.
However, no gains come without compromises. Having the pull-rod mounted to the top wishbone creates much greater loads in the wishbone. This means the wishbone and its mounting with the chassis need to be stronger, this will cost some weight.
Ferrari appeared to have struggled in the first test. With so many new solutions on the car it's hard to pinpoint what might be causing the issues. Going its own direction with pull-rod suspension at the front might be seen a risk this year, but with suspension simulation on both computer software and on the seven-post rig, it's unlikely the pull-rod set-up will be contributing to the problems.
Overall, the gains for a pull-rod set-up are small, but clearly worth chasing. Ferrari has stolen a march on its competitors with the front pull-rod. Its rivals will not be able to react to the change this year, due to a completely now monocoque and front suspension being needed. For such a small gain, this would be a time consuming and expensive change mid-season. No doubt this concept will go onto the "to do" list of the design teams for their 2013 cars.
Above is from ScarbsF1
So while some here think the front pull-rod is a problem. Many don't. Including Ferrari which operates their own F1 team. The bottom line has nothing to do with ego or being too proud to say you messed up. Teams want to win, bottom line. If they see something isn't working and it's detrimental, they fix/change it. There are too many engineers and too much pressure to keep the pull-rod if it isn't working because they're afraid to admit it.
