Why is a roof rack noisy? 7 reasons of a roof rack noise / hum / whistle.

So, you are driving a car with a roof rack, and at speed you start to hear a noise. At the same time, there is no autobox, bicycle carrier or any other load on the roof, that is, the roof rack is noisy by itself.

In this article (+ video), we will look at 7 reasons for the noise, hum or whistle from the roof rack and in each case we will present solutions to the problem.

#1 Crossbar profile

Reason number one is the crossbar profile. If the crossbars of your roof rack are rectangular in profile, then you most likely cannot avoid noise at speed. Let's consider the nature of this noise in a little more detail. At speed, the air flow meets the frontal part of the crossbar and bypasses it from above and below. And beyond the crossbar, the flow breaks down, forming a Kármán vortex street. The main thing in this process is that all the main noise occurs behind the crossbar, and not at all in front, where the crossbar "collides" with the air flows.