To better answer your question about whether car bike racks are safe or not let’s split it into two parts (I have in-depth articles that address both these issues so click on the links to learn more):
In short, car bike racks are quite safe in general if they have been properly installed. However, there are different bike rack types and some of them are completely safe while others can cause damage under certain circumstances:
- Hitch bike racks can’t damage your car no matter what. Though they might damage your bikes,
- Roof bike racks are highly unlikely to damage your car and it is impossible for them to damage your bikes,
- Trunk-mount bike racks can damage your car and your bikes as well.
Are trunk-mount bike racks safe?
Trunk-mount bike racks is the least safe rack type:
- It can damage your car if it is not installed properly or overloaded (can leave scratches, dents or even destroy the rear window). This is the case because this bike rack type will be directly contacting parts of your car,
- Also, it can damage your bikes since they will be probably hitting each other, which will result in scratches on bikes. Moreover, the exhaust can explode the wheel or melt the carbon frame (if the wheel is in the path of the exhaust).
Are hitch bike racks safe?
Hitch bike racks are much safer in comparison with trunk-mount racks. Moreover, I would say they are pretty much safe overall:
- A hitch bike rack can not damage your car since it is getting installed on a trailer hitch so it won’t directly contact elements of your car,
- You have to watch out for the exhaust to keep your bikes safe. Otherwise, your bikes can get damaged if they get in the path of the exhaust. The good news though is that your bikes won’t be hitting each other (at least on platform hitch racks) so it is not a concern when it comes to this bike rack type.
Are roof bike racks safe?
Roof bike racks are the safest ones given that you take very seriously and always keep in mind that your car is now basically twice higher:
- A roof bike rack can seriously damage your and other property if you forget about its height. The most common way how it happens is that a roof bike rack owner drives in the garage forgetting about the roof rack. A roof rack itself is very unlikely to damage your car,
- A roof bike rack can not damage your bikes no matter what. This is the safest bike rack type from this perspective.
Conclusion
I would not recommend buying a trunk-mount bike rack if you own an expensive car or expensive bikes. The chances are high that one day you will damage your car. Moreover, bikes will get scratches since they will be hitting each other.
Roof bike racks and hitch bike racks are much safer and have quite a low potential to damage your car or bikes. It is true that they cost significantly more in comparison with trunk racks, but it might save you money eventually since your car and bikes won’t get damaged.