Suspecting the Suspense behind the Suspension

The Suspension, the thing that goes up and down preventing you from going up and down.
Apart from keeping you all plush and snug, the suspension is also responsible for keeping the tyres plastered to the road.
The very term “Suspension” is not that technical at all.
Imagine yourself standing on a hard floor; you can feel all the vibrations and the trembling around can you?
Now place a trampoline on the floor and stand on it, Feel the difference don’t you? The vibes and quivers are all gone right.
This is precisely how a suspension system works.

What’s a Car Suspension? You ask?

A Car Suspension – An associated system of Linkages, Bearings, Springs and Dampeners that function in unison to give you an enjoyable ride subsequently keeping the vehicle glued to the road.
It also reduces the wear and tear on the vehicle, Provides consistent handling and braking.
Not only that, but the system also establishes that the vehicle maintains a balanced geometry at all times, through every twist and turn. It ensures the wheels stay true concerning the road.

One should also credit the invention of the suspension system that prevents you from severe spinal injuries. Without a proper dampening system, Potholes and craters on the road will break your back or at least give you a sore bum.

There are three common variations.
Viz.

A Dependent Suspension System

A fundamental and early form of the suspension system that has equally basic mechanics. This type has a solid axle linking both the opposite wheels which allow them to function as one unit. When one wheel undergoes an action, the other will follow due to dependency. Widely used in heavy haul trucks in India.

Examples of Dependent Suspension System:
Leaf Spring– The most orthodox one. A set of tightly packed plates of steel jerry-rigged to the axle that provides the dampening. Can be used transversely or longitudinally.

By Jim Gill -https://bit.ly/2ISjB4t 
Beam Axle– Popularly found in Front Wheel car. A solid shaft connects both the wheels with the presence of a trackbar. The action on one wheel gives a reaction on the other wheel (Beam Axles can be both “live” and “dead” axles).

The Good
-Supreme rigidity and unmatched toughness
-Can handle a lot of loads, work effortlessly under strain
-Easy to maintain and manufacture owing to its fundamental constitution.

The Bad
-A jolty, noisy and harsh ride
-Can be a bit counterproductive for the vehicle as it provides less room for flexibility.
-Poor assistance regarding vehicle’s handling

Independent Suspension System

Now things get interesting. In an Independent Suspension System, every wheel and their linkages are not connected in the sense that every part functions to the tune of autonomy. Independent Suspension does not have a single axle connecting each other which enables them to behave accordingly to the road conditions not just mimic or alternate the action of the other wheel.
Another USP of the independent system is that they make the ride like you are floating on the road, seamless and jerk-free.

Examples of Independent Suspension System:
MacPherson Strut– also known as Single Wishbone type. In brief, there is a wishbone-shaped linkage that provides a mounting point to the axle; A Coil spring is vertically mounted to the Chassis (Shell) of the car. An anti-roll bar is often employed in such types to boost its rigidity.
This is a prevalent dampening solution used in cars today.
Developed my Earle S. Macpherson for General Motors in 1947.

Double Wishbone Type– More like a reworked and evolved MacPherson type that uses two Wishbones instead of one (H-arms, A-arms). This one offers a more ductile geometry.

By Jonathan D Borgia – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39413950

Multi-link Suspension System– Uses three or more lateral arms also in a longitudinal configuration that act as linkages. Every arm has a different reaction equation. The arms also fulfil the role of controlling the Camber and the Castor.
Bleeding edge in Suspension Technology hence used generously in Sportscars.

The Good
-Ensures a comfortable ride as it is more flexible and allows each component to act individually
-Greater adjustability, Provides excellent feedback to the driver inducing Driver-Car engagement.
-Better Stability, Steering and Control.

The Bad
-Requires more maintenance, due to complexity in the build process.
-A bit fragile compared to Dependent type Suspension
-As this system see various angles of movements, This suscept the vehicle to see more wear and tear.

The Semi-Independent Suspension System

The median point between the Dependent and the Independent Suspension as the name suggest.
They operate at some level of autonomy per wheel which is only limited to how flexible the connections are. These are put to use on heavy haul vehicles.

Popular examples for Semi-Independent Suspension:
Torsion Beam Type– Also known as Twist Beam Axle type. The dampening effect is achieved through the twisting and bending of the suspension components under load. A longitudinal cross beam controls how each wheel behave. It is described as a Semi-Independent as the two wheels react to deflection individually but still act in association thus giving them some semblance of autonomy.

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De Dion Tube– Pretty old school stuff that uses Universal Joints at both the Hub and the Differential and plays no part in delivering power to the wheels hence, it is a dead axle. The longitudinal tube is complimented by leaf springs but has been replaced by coils nowadays.
De Dion tube is hardly used today with some exceptions.

By Elmar Eye from Göteborg, Sweden – De Dion axle, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=50369751

The Good
-Provides some level of independence to the wheels sans the complex build geometry
-Easy to fix and manufacture

The Bad
-No room for tweaks and mods, therefore, no flexibility.
-These offer less isolation than independent systems thus, NVH (Noise, Vibration, Harshness) filter into the cabin.

Honourable Mentions

The Bose Suspension System– What? Bose! The company that makes sound systems and audio instruments? Yes, you heard it right. In 2004 engineers at the Bose facility unveiled a radical new bleeding edge technology that used Linear Electromagnetic Motor at each wheel instead of the conventional shock and coil setup which was a stellar feat in technology, but that drove the manufacturing costs to skyrocket high. Honda, Toyota and even Ferrari showed interest, but when it came down to manufacturing, it was a bummer.
Update: ClearMotion has now acquired the Bose Suspension tech, an MIT enabled company, and they plan to bring it to the roads soon. Fingers crossed.
Watch This:

Magnetic Suspension System– Take a shock-absorber and fill it with Magnetic Polymer Liquid and plonk a smart ECU…That’s it! You get the Magnetic Suspension.
“MagSus” (as we like to call it) can react to rough road conditions thousand times per second.
The ECU anticipates oncoming conditions and can alter the state of the magnetic liquid to almost rubbery-like to solid that provides various dampening properties (Crazy right?).
Used in high-end luxury and sports cars.

With all That Clear, Here are the 5 common Suspension Problems.

Air Suspension System– The concept is simple as it sounds, An electric motor or the engine drives the compressor which inflates or deflates a textile reinforced rubber bellow (or airbags)that provides the dampening effect raising or lowering the chassis from the axle.
Used extensively in passenger buses and shuttles and even some luxury sports cars and SUVs (like Land Rovers)