Weight & Balance for Roof Racks

The right weight & balance for Roof Racks

4WDs are often used to carry heavier loads. A Roof Rack allows the vehicle to carry even more load than usual. But we must be careful as the position of the load will alter the centre of gravity of the vehicle, and this significantly affects the vehicle’s handling.

Roof racks, especially when loaded, will raise the vehicle’s centre of gravity. The effect is reduced with an aluminium roof rack and when carrying a lighter load. The effect is also reduced if the load is lower down, inside the vehicle rather than on the roof rack. We should optimise our setup, using a lighter roof rack and distributing the load appropriately, so our vehicle will handle it in the best way possible.

It is a little bit too simple to say that the load should be distributed in a completely even way, 50% over the front wheels and 50% over the back (50/50). The issue is complex because the centre of gravity will alter slightly as the vehicle moves. When a car accelerates the weight effectively moves over the back wheels, which reduces the ability to steer with the front wheels. When a car decelerates, say when using the brakes, the weight effectively moves of the front wheels, which can reduce the effectiveness of the brakes, and the ability to stop in time.

The effect of weight distribution is perhaps most noticeable when braking into a corner. The weight effectively moves forward, so the rear wheels lose traction and the brakes are less effective. This can cause the vehicle to slide outward.

To help compensate for these inevitable laws of physics a 4WD may have its equipment loaded to put slightly more weight over the back wheels. 60% over the back wheels and 40% over the front (60/40) seems optimal. This helps traction on the back wheels and means the weight distribution should effectively be 50/50 when braking.

Even with optimal loading of equipment in a vehicle, keep the weight at a lower height with slightly more over the rear wheels, the vehicle should be driven even more carefully than usual. Avoid rapid acceleration and brake early and gently. Also, drive a little more slowly.

Do you need more storage?

A Ute Drawer System and Ute tray toolboxes are used to storing equipment in the back of a van or utility vehicle. Some of this equipment may be heavy, altering the weight distribution in the car. This will affect the handling, though as the weight is positioned fairly low down it should not raise the centre of gravity too much. For this reason, it is better to put equipment in Ute storage boxes rather than on roof racks, keeping the centre of gravity low and the vehicle handling closer to normal.

Talk to our Roof Racks specialist in Perth

Need tradesmen Roof racks, Tray toolboxes, and a Ute drawer system to provide extra storage space in a vehicle?  Contact our team on 1300 303 681 and increase your productivity.