Do you hear a constant whistle or low hum coming from your roof while driving at higher speeds? When your car has a roof rack, that sound might be more than just background noise. It’s likely wind resistance creating turbulence around the bars. While it’s a common issue, especially on highways, it can be distracting and make your ride less enjoyable.
We’ll explain why roof racks make noise and what you can do to reduce or eliminate it.
Why Roof Racks Make Noise
Roof racks interfere with the way air flows over your car. Your vehicle is designed to be aerodynamic, allowing air to pass smoothly over the body. When you add a rack, even if it's empty, it changes that airflow. Crossbars, mounts, and attachments create small pockets of turbulence that turn into noise once you’re traveling at speed.
The most common sounds include:
- A high-pitched whistle caused by air passing through gaps or around rounded edges
- A low-pitched hum or drone from wider bars or attachments that create more drag
- Rattling or vibration if any part of the rack is loose
The faster you go, the louder the noise tends to get. Some setups start making noise as low as 40 mph, while others stay quiet until you’re past 60.
Not All Roof Racks Are The Same
The amount of noise depends heavily on the design of your rack. Round or square bars tend to be noisier than aerodynamic or wing-shaped ones. Factory-installed racks are often quieter because they’re engineered to match the contours of the vehicle.
Aftermarket racks may fit different vehicles and carry more gear, but they don’t always follow the same aerodynamic principles. That doesn’t make them bad, but it does mean they’re more likely to cause wind noise if not installed properly or if left uncovered when not in use.
Accessories and Attachments Can Add to the Noise
Even if your rack is quiet on its own, adding a bike mount, cargo box, kayak carrier, or snowboard rack can create new turbulence. These accessories interrupt the airflow in different ways and often add more surfaces for the wind to grab.
The shape and position of these items make a difference. A cargo box with a smooth, tapered front is less likely to whistle than a flat-edged carrier. Placing attachments farther back on the roof can also help reduce the amount of wind they catch.
How to Reduce Roof Rack Noise
There are several easy ways to reduce or eliminate roof rack noise without sacrificing functionality.
Start by checking that everything is properly tightened. Even slight looseness can cause parts to vibrate or shift in the wind. Next, consider installing a wind fairing—an angled plastic deflector that mounts to the front of the rack. Fairings redirect airflow over and around the rack, cutting down on turbulence and noise.
You can also try repositioning the crossbars. Moving them closer together or adjusting their tilt can make a surprising difference in how the air flows around them. If your rack has removable bars and you’re not using them, taking them off entirely is the most effective solution.
Upgrading to an aerodynamic bar design is another good option. Many manufacturers now offer oval or teardrop-shaped bars that reduce wind drag significantly compared to older round or square styles.
Does That Noise Mean a Bigger Issue
While wind noise is common, some sounds could indicate a mechanical problem. If you hear clunking, rattling, or clicking that doesn’t change with speed, check the mounting hardware. Loose bolts or worn components can make noise and compromise the safety of your setup.
If you’ve recently installed a new rack and the noise is sudden or unusually loud, it’s worth having it inspected. Improperly torqued hardware or misaligned mounts can create extra noise and risk damage to your roof or cargo.
B&C Auto Center – Roof Rack and Accessory Help in San Jose, CA
At B&C Auto Center, we help San Jose drivers get the most out of their vehicles without putting up with unnecessary noise or vibration. Whether you’re hauling gear for a weekend getaway or just want to improve your daily commute, we can inspect, adjust, or upgrade your roof rack system for better performance and a quieter ride. Visit us today and ride in peace.