Roof-Racks have evolved from utilitarian galvanized steel frames with wooden slats to alloy silver, grey or black hammer-tone powder coating with matching slats. They look better, are lighter and more durable to corrosion. although alloy racks are lighter they are not as strong as steel and overloading an alloy roof-rack will cause failure long before a similar load would damage a steel rack. I have fitted roof racks to all ten 4x4s I have owned and so roof racks have become a part of my everyday life. I have had good ones, troublesome ones, noisy ones and ones that are just right. What follows are some insight into roof-racks which will hopefully enable you to select one right for your purposes.
One of the most important elements of roof-rack design are the feet. If the feet are too narrow it will cut through the vehicle’s roof gutters. With vehicles designed to twist, such as Land Rover Defenders, full-length feet can damage the roof. Despite the claims by rack manufacturers, this happens! If full-length feet are fitted, the rack must be designed to twist with the vehicle.
Particularly important are the feet fitted to gutterless rooves. More and more vehicles are being produced with gutterless rooves and this, at first, posed a problem for rack designers. Ask your dealer to show you how the rack will be mounted and make sure the mount a plate inside the roof onto the part of the roof designed by the vehicle manufacturer for the mounting of a rack. On some vehicles this means removing the interior roof lining, which is time consuming and while not the easy way, the only way. Some rack makers still use Riv-Nuts (a nut that is fixed in position like a blind or pop rivet), although they have been proved many times not to be strong enough!
There are two major rack makers in South Africa. Outback and Front Runner are the two biggies. There are smaller manufacturers like Hannibal, Big Country and a few others, whose racks are less aesthetically-pleasing but sometimes stronger than both Outback and Front Runner’s. The bigger companies have been able to spend money on extrusions which in some ways have given them an advantage with their designs and has enabled them to create system designs, that means that clamps for Jerry cans, hi-lift jacks and spades can simply be bolted on. These systems are convenient and work well. But have they done this at the expense of strength? Sometimes I think so.
weight and load limits
Vehicle manufacturers sometimes supply a recommended maximum weight permitted on the roof. This figure is based on two things: the strength of the roof supports and the liability of the suspension to keep the vehicle on its wheels in the event of a violent swerve. Once a raised suspension is fitted to a vehicle, the maximum permissible roof load IS REDUCED, not increased as some claim. Did you know that the maximum permissible roof load on a Land Rover Defender is just 75kgs? Some claim it is 150kgs. I am not sure which is correct, but given the Defender’s handling, I reckon it’s 75kgs. Most vehicles are around 100-150kgs. Vehicles with the highest roof loading specs of 200 kgs are Mercedes G-wagen, Toyota Land Cruiser 70 wagon and Nissan Safari. The result of overloading a roof rack begin with a cracked windscreen, maybe broken springs, bad handling due to too much weight on the front springs or even complete loss of vehicle control resulting in injury or death. An overloaded roof-rack has the potential to kill you! Mounts on gutterless racks are not as strong as those fitted to gutters, so operators of vehicles with gutterless roof-racks should compensate even more, keeping heavy items inside the vehicle. Roof-racks that extend beyond the windscreen are a recipe for disaster. The front roof pillars are weakest, so are the front springs. This kind of rack also seems to cause instability at speed.
Racks-Responsibility for breakages
If any rack maker ever claims that they have never had a failure of one of their racks, I believe they are lying. Potential law suites prevent me divulging details but one South African manufacturer makes this claim, adding that the feet they supply are,’not part of the rack’, even though they are sold with, supplied by and made in the same factory as the rack. When a breakage occurs, their standard response is, the client overloaded it’. Shop around because not all racks or add-on fittings are made alike.