The terms we use are: Torsion bar, this is in fact a tube not a bar and acts as a spring, it replaces the conventional coil spring. Torsion bars are hollow tubes of metal (generally some form of steel) with shorts splined ends to connect to the rocker and chassis. where as a coil spring provides stiffness when compressed a torsion bar provide stiffness when twisted. The Rate of stiffness of the bar depends on its material, length and inner\outer shaft diameters. An antiroll bar without the levers is a use for a torsion bar.

Rocker, also known as bell crank or linkage, this is the lever that translates the push\pull rods motion into the rotary force on the torsion bar and the up\down motion of the damper. the rocker also has mounts for antiroll bars and sensors for wheel travel. The Ratio of the rocker in the lever is has on the damper, i.e. 1 inch of wheel movement translates to 2.5 inches of damper movement. generally damper movements are larger than wheel movements, hence the distance form the damper mount to the centre of the rocker is longer than the one connection the pushrod.

Pushrod pull rod, the difference as the name suggests is the whether the rod pushed up to the rocker or pull down to the rocker. Pull rod was first brought to F1 by Gordon Murray as Brabham in the 70s, the Pull rod set up has a strut from the outer end of the upper wishbones that runs diagonally to the lower edge of the chassis and "pulls" a rocker to operate the spring\damper. A pushrod is the opposite, the strut runs from the lower wish bone to the upper edge of the chassis. Choice between the two is geometry and CofG, also a pull rod will flex in droop (wheel going down) and push rod will flex with the wheel in bump (wheel going up) hence F1 pushrods are large carbon moulding to withstand the flex from the high wheel loads. MostF1 cars now use push rods, the high nose makes it impossible to locate a rocker low down on the chassis and still have the right geometry. Minardi this year and arrows last year used pull rods with low noses to lower the centre of gravity.

In the typical torsion bar pushrod set up described below the torsion bars pass through the centre of the rockers and fix to the front of the chassis. The Rocker pivots on the torsion bar. The push rod pushed the rocker and twists the torsion bar to provide the spring in the suspension, the rocker then compresses the damper and operates the antiroll bar if the car is in roll.

Black - Pushrod
Yellow - Rocker
Dark Yellow - Rocker splined to Torsion bar
Light grey torsion bar
Red - Damper
Blue antiroll bar linkages