Why Independent Suspension Improves Vehicle Roll Performance

Vehicle roll-overs are catastrophic dynamic events. In this blog we highlight why Independent Suspension provides significantly improved roll performance.

As a vehicle changes direction due to steering input, a lateral force causes the vehicle to lean in the opposite direction which, typically due to a combination of a high centre of gravity, speed, load shift and steering input, can result in a vehicle rollover event.

You cannot change the Laws of Physics, so what can you do?

The roll-over threshold of a vehicle can be calculated from 1st principles and further analysed with dynamic modelling. While the Laws of Physics remain constant, vehicle OEM’s can take steps to reduce the risk of vehicle roll-over by increasing the roll-over threshold of a vehicle. Compared to a beam (live) axle, Independent Suspension (I.S.) provides significantly improved roll performance.

As shown below, roll stiffness for a beam axle is a function of the spring spacing squared, whereas roll stiffness for an I.S. is a function of the track width squared, and since t2 >> s2, the vehicle roll-over threshold is improved.

Advantageously, this increased roll stiffness can eliminate the need for a sway bar, thus further improving vehicle performance, especially off road. Depending on the type of I.S. on the vehicle, cornering performance is further improved with camber compensation provided by the suspension geometry.

Over 50 years of experience in understanding Vehicle Dynamics.

Timoney suspension systems allows vehicle drivers to operate safely and productively in on-road and off road environments. Roll performance can, of course, be further enhanced with the use of multi-rate springs, hydro-pneumatic struts and/or control systems. The theoretical performance of all these systems can be predicted using our proven state of the art dynamic modelling methodologies.

Interested in finding out more? Contact one of our team here.