Roof bars are a crucial component for transporting gear on your vehicle, but their placement can significantly affect their performance and safety. Proper positioning ensures that the bars are both functional and aerodynamic, minimizing noise and reducing the impact on fuel efficiency.
General Guidelines for Roof Bar Placement
1. Manufacturer Recommendations
Most vehicle manufacturers provide specific guidelines for roof bar placement. These guidelines are usually included in the vehicle’s manual or the roof bar installation instructions. Typically, there are markings on the roof rails that indicate the maximum forward and rearward positions.
2. Balance and Weight Distribution
To maintain balance and ensure even weight distribution, it is crucial to position the roof bars at an appropriate distance apart. A common practice is to place the front bar about four to six inches from the maximum forward position, ensuring that the load is centered. This setup helps in maintaining stability, especially when carrying bulky items like roof boxes or bicycles.
Specific Considerations for Different Loads
1. Roof Boxes
When mounting a roof box, the placement of the bars can affect the aerodynamics and accessibility of the box. Users have found that positioning the front bar too far back can cause the box to sit at an awkward angle, increasing wind resistance and noise. Conversely, placing it too far forward can interfere with the vehicle’s hatch. A balanced approach is to have the front bar slightly forward, ensuring the box is level and the rear hatch can open without obstruction.
2. Bicycles and Kayaks
For carrying bicycles or kayaks, the roof bars need to provide adequate support without causing excessive drag. Placing the front bar further forward can help distribute the weight evenly and reduce the aerodynamic drag. However, ensuring the bars are not too far apart is critical to prevent the load from shifting during transit. Users often adjust the bars based on the length and type of the gear they are carrying to find the optimal balance between stability and aerodynamics.
Tips for Reducing Noise and Drag
1. Using Fairings
Adding a fairing to the front bar can significantly reduce wind noise. Fairings are aerodynamic devices that direct airflow over the bars, minimizing turbulence and the resultant noise.
2. Ensuring Proper Tightening
Loose roof bars can cause rattling and additional wind noise. Regularly checking and tightening the bars ensures they remain secure and reduces noise. It is also essential to ensure that all mounts and attachments are properly secured, as even small gaps can cause significant noise at highway speeds.
3. Streamlined Accessories
Using streamlined accessories designed to work with your roof bars can also help reduce drag and noise. For example, aerodynamic roof boxes and low-profile bike mounts are designed to work with the airflow over the vehicle, minimizing their impact on fuel efficiency and noise levels.
Safety and Legal Considerations
1. Legal Restrictions
Different regions may have specific legal restrictions regarding how far roof bars can extend beyond the roof of the vehicle. Ensuring that the bars do not extend beyond the allowable limits is crucial to avoid fines and ensure safety. Checking local regulations before setting off on a trip can save time and hassle.
2. Load Limits
Exceeding the recommended load limits for your roof bars can be dangerous. Most manufacturers specify a maximum dynamic load (while the vehicle is moving) and a static load (when the vehicle is stationary). Staying within these limits ensures that the roof bars and the vehicle’s roof structure are not overstressed, preventing accidents and damage.
Conclusion
The optimal placement of roof bars varies depending on the type of load and the specific vehicle. Following manufacturer guidelines, ensuring balanced weight distribution, and considering aerodynamics are crucial steps in achieving the best setup. Regular maintenance and using additional accessories like fairings can further enhance the performance and safety of your roof bars. By paying attention to these details, you can ensure that your roof bars are both functional and efficient, providing a safe means of transporting your gear.