Dependent Front Suspensions
Dependent front suspensions consist of a rigid front axle that connects both front wheels together. The front axle is basically a solid bar that is usually kept in place by leaf springs or shocks. This type of setup has a lot of disadvantages and is a bit dated. This is because both front wheels travel at the same time which may pose a disadvantage to the car on uneven or bumpy roads. The rigid bar connecting the wheels could cause unnecessary oscillation between the wheel assemblies which would be disastrous for handing at high speeds. This type of suspension has lost popularity and has almost been phased out since the inception of independent front and rear suspension setups.
Independent Front Suspensions
Independent front suspensions are more commonly used today in automotive applications as they allow each wheel to travel independent to the other (except when connected by an anti sway bar). These setups usually consist of a strut assembly attached to an A-arm or more commonly a “wishbone” The wishbone has two mounting points that attach to the vehicle body and one that is attached the the lower end of the strut assembly. The benefits of this type of system are overall better handling and ride comfort.
Adding a second wishbone to the assembly allows for even greater adjustment and control of the vehicle ride. The addition of the second wishbone allows for greater camber adjustment also along with minimizing roll and sway. Double wishbone suspensions are usually found in larger and heavy duty vehicles.
The McPherson Strut is the most commonly used suspension assembly in modern cars and comes in many variations all essentially doing the same job which is to provide the most amount of contact with the road possible.
Dependent Rear Suspensions
Just as with dependent front suspensions, dependent rear suspensions consists of a solid axle linking both rear axles together so they move in unison adapting to changes in the road. The rear setup could be used with either leaf or coil springs and also allowed for the use of a strut if needed that attach to the axle. The simplicity and adjustability of this design made it popular with American car manufacturers especially in early manufacturing days along with how cheap it was to build. The main drawback is the lack of a fixed lateral point so the rear has a tendency to wiggle left to right.
Independent Rear Suspensions
The principles of an independent rear suspension are the same as the front. Each wheel is attached to the axle by a wishbone and is able to move freely and independent from the other wheel. The benefits for this setups are improved handling and ride comfort just as the front. Any vehicle that has both independent front and rear suspensions systems can be referred to as having “four-wheel independent suspension”
There are many different derivatives of all of these types of suspensions and this section will be expanding soon to cover some of them. Please feel free to contact me with any question on specific types of suspension designs and their characteristics.