Dual-pivot steering geometry (also known as virtual pivot) is a geometric arrangement of linkages in the steering of a car designed to reduce or eliminate
scrub radius
In an automobile's suspension system, the scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. It can be positive, negative or zero. ...
by moving the pivot point of the
king pin outboard, in order to improve steering precision and straight line stability.
[2009 Hyundai Genesis Coupe: Suspension Walkaround](_blank)
by Dan Edmunds, 2009, Edmunds.com. Accessed October 2014.
It is typically used with a
MacPherson strut
The MacPherson strut is a type of automotive suspension system that uses the top of a telescopic damper as the upper steering pivot. It is widely used in the front suspension of modern vehicles. The name comes from American automotive engineer ...
, but can also be applied to a
double wishbone suspension
A double wishbone suspension is an independent suspension design for automobiles using two (occasionally parallel) wishbone-shaped arms to locate the wheel. Each wishbone or arm has two mounting points to the chassis and one joint at the knuckl ...
.
[2009 BMW 750i: Suspension Walkaround](_blank)
by Dan Edmunds, 2009, Edmunds.com. Accessed October 2014. In either case, the difference is that the single bottom wishbone is replaced by a pair of
suspension link
300px, 5-link live axle suspension
In automotive suspensions, a suspension link, control link or link is a suspension member, that attaches at only two points. One point being the body or frame of the vehicle and the other point attaching to th ...
s forming a trapezoidal
four-bar linkage
In the study of Mechanism (engineering), mechanisms, a four-bar linkage, also called a four-bar, is the simplest closed-Kinematic chain, chain movable linkage (mechanical), linkage. It consists of four Rigid body, bodies, called ''bars'' or ''link ...
. This allows the kingpin to pivot about a pivot point nearer the center of the wheel's contact patch instead of the traditional pivot point at the
ball joint
A ball is a round object (usually spherical, but sometimes ovoid) with several uses. It is used in ball games, where the play of the game follows the state of the ball as it is hit, kicked or thrown by players. Balls can also be used for si ...
of the bottom wishbone.
See also
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Scrub radius
In an automobile's suspension system, the scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. It can be positive, negative or zero. ...
*
MacPherson strut
The MacPherson strut is a type of automotive suspension system that uses the top of a telescopic damper as the upper steering pivot. It is widely used in the front suspension of modern vehicles. The name comes from American automotive engineer ...
*
Double wishbone suspension
A double wishbone suspension is an independent suspension design for automobiles using two (occasionally parallel) wishbone-shaped arms to locate the wheel. Each wishbone or arm has two mounting points to the chassis and one joint at the knuckl ...
*
King pin
*
Steering
Steering is the control of the direction of motion or the components that enable its control. Steering is achieved through various arrangements, among them ailerons for airplanes, rudders for boats, cylic tilting of rotors for helicopters, ...
*
Four-bar linkage
In the study of Mechanism (engineering), mechanisms, a four-bar linkage, also called a four-bar, is the simplest closed-Kinematic chain, chain movable linkage (mechanical), linkage. It consists of four Rigid body, bodies, called ''bars'' or ''link ...
*
Ackermann steering geometry
The Ackermann steering geometry (also called Ackermann's steering trapezium) is a geometric arrangement of linkages in the steering of a car or other vehicle
A vehicle () is a machine designed for self-propulsion, usually to transport people ...
*
Control arm
In automotive suspension, a control arm, also known as an A-arm, is a hinged suspension link between the chassis and the suspension upright or hub that carries the wheel. In simple terms, it governs a wheel's vertical travel, allowing it to mo ...
*
Radius rod
A radius rod (also called a radius arm, torque arm, torque spring, and torsion bar) is a suspension link intended to control wheel motion in the longitudinal (fore-aft) direction. The link is connected (with a rubber or solid bushing) on one end ...
References
External links
Car-engineer.com: MacPherson and Pseudo-MacPherson Suspension
{{Automotive handling
Automotive steering technologies