Suspension Types: Front
So far, our discussions have focused on how springs and dampers
function on any given wheel. But the four
wheels of a car work together
in two independent systems -- the two wheels connected by the front axle
and the two wheels connected by the rear axle. That means that a car
can and usually does have a different type of suspension on the front
and back. Much is determined by whether a rigid axle binds the wheels or
if the wheels are permitted to move independently. The former
arrangement is known as a dependent system, while the latter arrangement is known as an independent system.
In the following sections, we'll look at some of the common types of
front and back suspensions typically used on mainstream cars.
Dependent Front Suspensions
Dependent front suspensions have a rigid front axle that connects the front wheels. Basically, this looks like a solid bar under the front of the car, kept in place by leaf springs and shock absorbers. Common on trucks, dependent front suspensions haven't been used in mainstream cars for years.
Dependent front suspensions have a rigid front axle that connects the front wheels. Basically, this looks like a solid bar under the front of the car, kept in place by leaf springs and shock absorbers. Common on trucks, dependent front suspensions haven't been used in mainstream cars for years.
Independent Front Suspensions
In this setup, the front wheels are allowed to move independently. The MacPherson strut, developed by Earle S. MacPherson of General Motors in 1947, is the most widely used front suspension system, especially in cars of European origin.
The MacPherson strut combines a shock absorber and a coil spring
into a single unit. This provides a more compact and lighter suspension
system that can be used for front-wheel drive vehicles.
The double-wishbone suspension, also known as an A-arm suspension, is another common type of front independent suspension.
While there are several different possible configurations, this
design typically uses two wishbone-shaped arms to locate the wheel. Each
wishbone, which has two mounting positions to the frame and one at the
wheel, bears a shock absorber and a coil spring to absorb vibrations.
Double-wishbone suspensions allow for more control over the camber angle
of the wheel, which describes the degree to which the wheels tilt in
and out. They also help minimize roll or sway and provide for a more
consistent steering feel. Because of these characteristics, the
double-wishbone suspension is common on the front wheels of larger cars.
Now let's look at some common rear suspensions
