Vehicle manufacturers typically provide load ratings, which you can find in the vehicle’s manual, online forums, and other sources. These ratings might seem lower than expected. But how are they calculated?

The load rating is primarily based on the vehicle’s dynamics, centre of gravity and rollover angels.

• Center of Gravity: Adding weight to the roof increases the vehicle’s overall centre of gravity. A higher center of gravity can negatively affect the vehicle’s handling steering and braking, making it more prone to lose control over the Vehicle, in extreme driving conditions, especially in sharp turns or during sudden evasive maneuvers.
  
• Roll Stability or Rollover angles: A roof load increases the risk of rollover, Vehicles with high roof loads (or with poorly distributed loads) have less roll stability, as the higher centre of gravity makes it easier to tip over.
  
• Suspension and Handling: The additional weight on the roof can affect the suspension’s behaviour. It may cause the vehicle to sag slightly, altering the suspension geometry and potentially degrading handling performance. This can result in less responsive steering and more body roll when cornering.

Manufacturers determine a safe weight limit that minimizes the risk of compromising the vehicle’s stability, and handling.

The True Strength of Your Vehicles Roof

Interestingly, the manufacturer’s load rating doesn’t necessarily reflect the roofs actual structural capacity.  Automotive Safety regulations require a vehicles roof to withstand three times the vehicle weight during a high-speed rollover. This means the roof can handle much more load than the given roof load ratings put forward by the manufacturer.

What Does This Mean for You?

If you’re planning to add accessories to your roof, it is crucial to consider the manufacturers load ratings and understand their purpose. If you wish to load your vehicles roof more than the specified roof rating, it is very important to be mindful of this, and to adjust your driving style when conditions require. Having more mechanical sympathy, so to speak, driving in a way that respects the limitations and characteristics of one’s vehicle when full loaded, ensures your safety and longevity of your Vehicle. 

Predator Offroad’s Load Ratings

Our roof racks are designed to endure significantly heavier loads than what we recommend for daily use. However, for optimal safety and performance, we advise adhering to the following load ratings:

Dynamic Load: This is the maximum weight your vehicles Roof rack can handle while driving. Keeping within this limit ensures stability and safety during your exportations.

Static Load: This is the maximum weight when the vehicle is stationary, such as when parked or when you’re using a rooftop tent. Staying within this limit allows for safe and stable use of rooftop accessories.

Example Setup:

Here’s a typical setup to illustrate what these weights look like:
Our SUV roof racks have a Dynamic load rating of 150kg:

• 77 kg for a Roof Top Tent
• 25 kg for an Awning

Total: 102 kg. This leaves 48 kg of capacity for additional accessories, ensuring you stay within safe limits.

When loading your Vehicles roof to maximum rated capacity, here are some upgrades to consider:

• Aftermarket Suspension: Consider installing a suspension system with a stiffer spring rate to handle increased load and body roll.
• Moderate Lifts: Keep any vehicle lift within a 2-inch range to avoid excessively raising the centre of gravity.

Conclusion:

For overlanders and adventurers who need to modify and accessorize their vehicles, understanding and respecting load ratings is crucial. With the right adjustments and driving style, you can safely enjoy a fully equipped vehicle. At Predator Offroad, we prioritize your safety and performance for every journey. Adapt your driving to your load, and you’ll be ready for any adventure that comes your way.

Predator Offroad Team