Noisy Roof Racks

One common complaint with aluminium roof racks in Perth, especially those made more than a generation ago, was the noise they made when the vehicle was moving. The crossbars of the rack were rarely aerodynamic, so they produced a lot of drag in the wind, which could produce an annoying vibration and audible tone when the vehicle hit a certain speed. This could be annoying to those in the car.

This sound of the airflow over the aluminium roof rack is called aeolian noise. This noise is far worse with a consistent shape and far worse with a flat surface facing into the airflow, say with a straight crossbar. The amount of noise depends on the speed of the airflow and the drag coefficient of the surface. A flat surface has a high drag coefficient, and a round surface (around the crossbar) has about half the drag. A good airfoil, which is designed to be aerodynamic, has a much lower drag coefficient, perhaps 5% of a square bar.

A modern roof rack is designed to provide minimal drag. This reduces noise and helps with fuel efficiency. Being able to custom design a rood rack to suit a particular make of vehicle helps to provide the best aerodynamic option.

Reducing noise on the roof rack you already have

Some roof racks add a wind fairing, which is simply a neat shield that directs air over the rack.

Another option is simply to provide padding on the crossbars. This softer surface prevents the crossbars from vibrating at only one frequency, so the roof rack no longer produces a humming sound. Padding also provides a soft surface when tying down a load, so that surfboards or other belongings do not get scratched, and do not move side-to-side on the metal bars.

Wrapping some cord around the roof rack bars will also help reduce noise by dampening vibrations, though it will not help with fuel economy.

Aluminium Roof Racks in Perth

A modern custom-designed roof rack is reliable and provides minimal wind resistance, so your vehicle travels a little more quietly, and with optimal fuel economy.

If you need vans, trucks, utilities, and other vehicles’ aluminium roof racks, we are your go-to company. Call us on 1300 303 681 or at www.jaram.com.au