The answer to this question mostly depends on bike rack type:
- Roof bike racks have the greatest potential to produce annoying whistling and howling. Don’t get me wrong though since not all roof bike racks are created equal. Some of them indeed can be quite noisy whereas others are pretty much quiet. Overall, I would give this bike rack type 5/10 for noise (where 10 means the maximum noise). Roof bike racks noise and tips on how to reduce will be covered in more detail further in the article,
- Hitch bike racks are not known to produce much noise. Especially premium models are very quiet (most hitch bike racks actually fall into this category), won’t cause any unwanted whistling or howling. You might hear some sound from the outside, but it will be really indistinct and won’t bother you as a result. This bike rack type gets 1,5/10 for noise (very little noise!),
- Trunk-mount racks are very similar to hitch bike racks in terms of noise. They are getting installed on the rear of your car as well as hitch racks. Therefore, they do not disrupt streamlining that much. Please keep in mind though that some cheap models might be wobbling causing some extra noise. Also, not tight enough straps can result in whistling. All in all, this bike rack type gets 3/10 for noise (little noise if properly installed, I would say).
What else can affect the noise level
The quality of a bike rack matters a lot when it comes to its noise. Premium segment bike racks do not produce much noise (even roof racks) since most of them are aerodynamic. Cheaper models can have square forms which do not help to reduce noise (to put it mildly).
Also, you need to take into consideration that some cars are less soundproof than others. So to speak, exactly the same bike rack might produce little to nothing noise if it is installed on a luxury SUV. Whereas on a less expensive car the noise level might be considerably higher.
Are roof bike racks noisy?
As I have mentioned earlier, roof bike racks can be noisy. It highly depends on the shape of a particular roof rack:
- Cheaper roof rack models mostly have square shape forms that cause quite distinct noise,
- High-end models are often aerodynamic, which is really a big deal when it comes to noise reduction.
Moreover, there is another big factor which is quite obvious. A loaded roof rack will be noisier than an empty one.
Anyway, if you will be using aerodynamic racks and your car is reasonably soundproof, you will be fine. You will definitely hear some howling from the top, but it won’t get to the level which is annoying.
How to reduce roof bike racks noise
a) Make sure that a roof bike rack is properly installed
First thing first, make sure that all elements of a roof bike rack system are properly mounted (both roof racks and bike racks). It may seem too obvious but some people still neglect it nevertheless.
b) Buying aerodynamic roof racks will help
If quiet road trips is your priority, then you need to consider buying aerodynamic racks. An aerodynamic roof rack system of really good quality will cost you around $400-$600 for the whole system.
Moreover, aerodynamic roof racks will have a less negative effect on mileage reduction. Especially if you are planning to use roof racks a lot, during long road trips, they will actually save you money.
c) A windshield fairing is the best solution
This is what will definitely help you out if you are experiencing loud noise. A windshield faring moves airflow up and over the rack to reduce drag. The wind noise becomes much more quiet as a result.
This is the best solution to this problem, in my experience. It really makes a big difference. On top of that, this roof rack part is relatively cheap in comparison with other roof bike rack elements. A high-end windshield faring can be purchased for $100-$150 (produced by premium brands such as Thule or Yakima).
There are two main things that you need to keep in mind buying a windshield faring:
- First of all, not all windshield fairings are perfectly compatible with all roof racks. In order to achieve the best results, buy a windshield faring of the same producer as your roof racks. If you have Yakima roof racks then Yakima windshield faring is your choice,
- Pick a windshield faring of the right size. You have to make sure that a windshield faring covers the whole length of your front crossbar but does not exceed it much at the same time. Most windshield faring models have different sizes (for example, exactly the same model can be 34, 40, 46 and 52 inches long.
Are there universal windshield fairings? Yes, some models are universal. However, as I have mentioned earlier I would not recommend going this way by default. You won’t save much money since even premium windshield fairings are not that expensive. At the same time, a universal windshield faring might not be a perfect fit.
Is it easy to install a windshield faring? Yes, you just need to attach it to the front crossbar and that’s basically it. The bottom part of a windshield faring simply rests on the car since it will be kept in place by the wind force.
Are trunk-mount bike racks noisy?
In general, they are not noisy at all when it comes to howling. I have not heard people complaining about them.
Cheap models though are usually poorly made. As a result, a bike rack can wobble producing quite disturbing sound (not howling and whistling but it is not any better).
Moreover, straps that were not properly tightened can whistle very loudly as well so make sure you have properly tightened them.
Are hitch bike racks noisy?
Hitch bike racks are the best choice if you are looking for a really quiet bike rack. In general, they do not disturb airflow much, especially on SUVs and vans. Therefore there is no much noise.
In the worst-case scenario, the noise will be pretty much tolerable (it will be more distinct on sedans and hatchbacks). However, as I said it won’t be a problem.
Conclusion
Summing up, the noise that comes from car bike racks is not a big issue in general. It is true that roof bike racks can produce annoying noise but it can be solved with the help of a windshield faring (which will not break the bank by the way).
Speaking about trunk-mount racks and hitch racks, they are normally quiet out of the box.