Leaf Spring Suspension

Leaf spring is the oldest form of suspension that can be dated back to horse drawn carriages of the medieval times. Leaf spring suspension was common on vehicles in the Europe up till the 1970s after which more sophisticated suspension setups were used on cars for better ride and handling. Leaf spring suspension is the most affordable suspension in the world and as such is still used in low price automobiles.

Leaf spring suspension consists of a slender length of steel spring of rectangular cross section in the shape of an arc. The centre of the arc is located on the axle while the ends can be mounted on to the body of the vehicle with the tie holes at the ends of the arc. Several layers of leaf springs with progressively shorter leaves can be used in the suspension of heavy vehicles to carry the heavy weight.

The advantage of leaf spring suspension is mainly for heavy vehicles as a leaf spring suspension disperses the load more evenly over the vehicle’s chassis. This reduces the pressure and structural loads unlike that for a coil spring suspension where the load is transferred to a single point.

However, the ride and handling traits of a car are compromised on a leaf spring suspension system as the load being spread over a larger area compromised the balance of a car. When the load is sent to a single point the chassis finds it easier to balance the car. Also the ride comfort of a car with leaf spring is compromised for the same reason of dispersion of weight which makes it hard for the suspension to iron out bumps. When the load is centred at a point it’s easier for a suspension setup to absorb and cushion bumps on the road.

Normal road cars are shying away from leaf spring suspension setups as better suspension setups that offer superior ride and handling are becoming more affordable.