Pull-rod suspension
In 1979, engineer Gordon Murray, working under Brabham, debuted an innovative pull-rod suspension system on the Formula One stage,[2] implementing the design into a BT49 racing car.
This new design was revolutionary, as the shift away from the archaic hydro-pneumatic suspension used previously allowed for a much lower ride height and aerodynamic efficiency on the BT49, securing a championship win over four seasons from 1979 to 1982 for Brabham.
Over the next two decades, the popularity of pull-rod suspension on formula racing cars fluctuated, yet steadily increased, and was being driven largely by innovation and optimisation by those teams continuing to utilise it.
In response to this, Red Bull Racing chief technical officer, engineer, and aerodynamicist Adrian Newey saw a new niche arise for pull-rod suspension.
As the RB5 race car's diffuser moved further towards the rear, he realised that pull-rod suspension would assist in optimising air flow under the vehicle and into its aerodynamic components.
[5][6] In a push-rod suspension system, there is an upper and lower control arm, similar in design to a double-wishbone frame, which provide a structurally integral connection between the wheel hubs and the chassis.
[7] On the opposite end of this rocker arm is a transversely mounted shock-damping coil-over, similar in design to those MacPherson struts commonly found in production cars.
[2] As a result of these factors, the push-rod layout is distinct from other suspension systems as, unlike others, it is able to be designed and assembled with components closer to, or further from, the centre of gravity of the vehicle.
Pull-rod suspension, being able to move components away from essential air channels, is therefore able to reduce the workload on the smaller engines and improve acceleration across the power band.
][9] In conventional suspension designs, having the shock dampers extend perpendicularly from the body creates an increased capacity for body-roll, as forces act directly upwards into the coils.
In pull-rod suspension designs, however, having the wishbones and dampers mounted transversely and in line with the body instead translates these forces longitudinally, leaving less room for body-roll and greatly improving cornering grip.
Due to these reasons, push-rod suspension sees common and widespread usage in track-focused racing leagues as its benefits extend to many aspects of the overall vehicle's performance.
Due to its simplicity, systems such as leaf springs or the MacPherson strut can be relatively cheap to design and integrate into a vehicle, and their wide usability make them a popular choice for such cars.
[9] In terms of usability for daily use, while push-rod suspension is highly effective on a maintained and smoothed track, it does little to soften impacts and forces while driving on active roads, resulting in a rough and uncomfortable ride.
