Ok now as the forum starts to settle down a bit with the changes lets come back to this topic one more time.
mep wrote:However I don't think this decouples roll and heave completely because the torsion bars are still able to twist under roll.
To my mind its completely decoupled. In pure roll you have the front ends of the torsion bars rotating in the same direction as each other and the transverse beam follows them.
Yes correct, for a suspensions without an antiroll bar. So when the car goes through a corner the body rolls to the side, causing both rockers moving synchronous as they are linked to each other with that solid bar and the torsion bars which will not twist in that case.
But so far this suspension does not have an antiroll bar. Which might be fine, maybe they don't need one at the front axle. But somebody here said there will be still an additional antiroll bar attached to the rockers and hidden in the picture.
I say it comes down to the design of this antiroll bar. I differentiate between two types of designs. One which allows for relative movement between the two rockers so the rockers are basically connected with a spring. The second one creates a solid link between the rockers and connects them with a spring to the chassis. It seems like the second one is much more common because it was easier to find a good picture for that design but anyways let's look at the first at the U-shaped design:
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In the picture you see the rockers are connected to the u shaped antiroll bar. The thin bar connecting the two sides is twisted in roll which requires a relative movement of the two rockers in relation to each other. With the Sauber suspension this movement is hindered by the extra bar connecting the rockers so it is only possible when the torsion bars get twisted. In that case there is a interrelation between the antiroll bar and the torsion bars. The stiffness of the torsion bars will add to the stiffness of the antiroll bar.
If we look at the second picture we see a T-shape design where both rockers are connected with a solid bar so they always move in relation to each other. The actual antiroll bar is the torsion bar connecting the t-bar to the chassis. With such a design and the torsion bars of the rockers having no fixed end but being able to rotate synchronous to each other, there is then actually a complete decoupling of roll and heave.
Shot at 2012-05-21
So this design still needs the construction for the anti roll bar whereas this could be prevented in case of the Sauber suspension by linking the connection bar itself with a spring to the chassis. A simple leaf spring would do that job so I wonder why they don't do that. Like I said earlier it might be the case that they just don't use an antiroll bar at the front.