There aren’t too many 4WD’s that are set up for travelling and camping that don’t have some sort of roof rack arrangement. With lots of different options on the market, there’s something to suit every requirement out there.
However, before you go out and lay your money down, there’s a bit to know about the different types, what you can use them for and how much weight you can legally carry.
Maxtrax, Oztent and LPG bottle loaded on the roof racks.
What’s the purpose of roof racks?
We’ll start off with the basics. If you don’t have a need for roof racks, then there’s no reason to have anything attached to your roof. Seriously; remove them if you can – it will save you money.
However, chances are if you are reading this you want some sort of additional storage, and that’s the main reason for fitting roof racks.
Whether it’s just a solar panel that feeds your second battery, or room to tie a few swags up top, the purpose of roof racks is to gain more storage. Mountain bikes, surfboards, kayaks, rooftop tents and even small boats are commonly transported on the roof of a 4WD.
I will quickly point out that sometimes you don’t need more storage, but you need to store things outside of the vehicle. You’ll often see fuel like petrol, diesel, portable toilets and LPG bottles on top of roof racks, because they are either unsafe, or they smell inside your 4WD.
Carrying the portable toilet on the roofracks outside of the vehicle.
What are the types of roof racks you can get?
1. Roof bars
Roof bars are the lightest, and least functional racks in terms of what you can attach to them. That said, they are the perfect solution for a lot of people who only want to attach fishing rods, or an Oztent, or something else that sits on top of the bars.
Some vehicles come with roof bars that run lengthways down the vehicle. These on their own are pretty much good for nothing, as you can’t actually use them to attach anything. You really want the bars to be running from side to side. The good news is it’s easy to adapt length ways ones to sideways ones.
Normal length ways roof bars.
Baskets are quite literally as the name suggests; a metal basket that you can put a variety of gear into, with edges that run around the side and mesh in between. These are usually fairly light duty and are not normally much more than a metre by a metre in diameter.
A standard roof basket is a fairly light duty option.
3. Full-length cages
These are the largest roof racks on the market and are similar to baskets although much heavier duty. You can get them with the sides missing, or with just the front and rear missing. This allows you to overhang larger items.
If you are touring full time, and have a lot of gear to carry around, these are by far the most popular option. I will mention you can get smaller versions of cages to suit single cab and dual cab utes too.
This is what a full-length roof cage looks like.
How much weight can you apply to the roof?
One of the most critical pieces of information that people overlook when installing roof racks onto a 4WD is the total weight the manufacturer has designed the roof to take. Every 4WD on the market has a roof loading capacity, and it’s based around the strength of the roof, and how it is supported.
For a large majority of 4WD’s, 100kg is the roof loading limit, with very few at 150 and 200kg. This is the total amount of weight you can put on the roof, and includes the weight of your roof racks themselves. If you exceed this rating, and damage occurs or you contribute to an accident because of it, your insurance company can legally decline or reduce a claim.
Beyond this, loading your roof up with more than what the manufacturer recommends is a recipe for something to go wrong. There have been plenty of instances of roof racks coming off roofs, or doing damage to vehicles because they were overloaded. To find out your roof load capacity, ring your vehicle manufacturer with your VIN handy.
There are lots of ways to load your 4WD up.
How do the roof racks attach?
There are a myriad of ways to attach roof racks. Some make use of gutters and clamp around them, while others require holes to be drilled into your roof. There are some on the market that bolt directly to your factory length ways racks, and others that clamp to the roof by going around the metal on the inside where your doors shut.
The only reason I mention this is because the way the roof racks attach is directly related to how strong they are. Poor quality gutter clamps will slide easily, and those that are quick release are often not designed for off-road use. The strongest roof racks will spread the load over a large portion of the roof.
There are a few different ways to attach roof racks.
What should you be carrying on roof racks?
Roof racks should be used for light and bulky gear that is too hard to fit into the vehicle, along with solar panels and LPG bottles. It’s not a good idea to carry excessive amounts of fuel on the roof racks, but a jerry can or two isn’t the end of the world.
Awkward items that have no chance of fitting inside your vehicle such as surfboards, kayaks and fishing rods are usually only able to be transported on roof racks.
Stay under the total allowable roof rating, the maximum rating of the roof racks, drive sensibly and you’ll be just fine.
All we carry on our vehicle is a solar panel and light bar.
Who sells roof racks?
These days, you can get roof racks from all over the place. That said, the most reputable brands are OEM (your vehicle manufacturer), Rhino Rack, Tracklander, Yakima, Thule and ARB.
Beware of using cheap roof racks for heavy duty applications, without some knowledge of their quality!
If you want a bargain on roof racks, wait for something second hand. You can easily save $500 on a nice, aluminium powder coated full-length roof cage.
An awning is a popular addition to a roof rack.
Keep it low
In theory, your roof racks should sit as low to the roof as possible. By this, I mean anything more than about 80 – 120mm is excessive. It increases your centre of gravity and fuel consumption unnecessarily. It’s scary when you see a big, heavy rooftop tent mounted 200mm or more off the roof of a 4WD, it’s totally unnecessary, with lots of downsides.
High lift and shovel holder mounts.
What’s the best material to use?
Most roof racks are made of aluminium or steel and sometimes have plastic components as well. Steel is cheaper than aluminium, which makes it popular. However, it’s also much heavier than aluminium and has a bad habit of rusting (even through powder coating) and putting rust spots on your roof (especially the cheap ones).
If you are going for small sized racks, you will get away with any material. However, the moment you go over around 30kg for the rack itself, you should be looking at aluminium.
There are full-length steel cages weighing in at over 70kg on the market today, and if you put that on a 4WD that’s only rated for 100kg then you have a tiny amount of weight available to actually use on the rack.
Considering the same full-length cage in aluminium is 15 to 25kg, there’s a major weight saving to be had. Combine this with the fact that they will never rust and wreck your roof, it’s a no brainer.
Standard aluminium roof bars are much lighter than steel.
Are they rated for 4WDing, or just on road use?
If you want your roof racks for use off-road, make sure you ask whether they’re designed and rated for off-road use. Many will have a 60kg weight allowance, but only for on-road use. Not very useful, on a 4WD!
Spare tyres on roof racks
A lot of people carry spare tyres on their roof racks, and that’s fine providing you watch the total roof weight and can get it up and down.
If you are unsure about what I mean, try and lift your spare up onto your roof racks. I bet you’ll either struggle, or you won’t be able to do it. Usually, this is only when two tyres are needed, and there’s only one tyre carrier on the vehicle.
The 40 inch light bar on our Dmax.
Roof rack accessories
One of the reasons roof racks are fitted is so various accessories can be fitted. These include awnings to give you some shade, spotlights or LED light bars (check with your authorities though), solar panels, shovel holders, high lift jack mounts and traction board mounts.
A 270-degree awning provides lots of shade.
What’re the disadvantages of roof racks?
There’s no free lunch with any 4WD modifications, and roof racks are no exception to this. They all provide some sort of wind resistance, and that means more fuel used. A small set of racks isn’t going to make a massive difference. But if you fit a big cage or a rooftop tent, expect it to use another 1 – 2L/100km.
If you really load a set of roof racks up (think 5 swags or a small roof topper boat) then your fuel consumption is going to suffer.
The wind resistance also creates noise, and whistling or high pitched noises are not uncommon. Fitting your vehicle into garages and underground parking can also become a problem.
Using a solar panel as a wind deflector.
Fit what you need
In the end, you need to match the roof rack to your requirements. If all you carry is a few fishing rods then a light duty set of aluminium racks will suit fine. However, if you plan on carrying fuel, solar panels and a heap of other gear you want something that’s up to the task.
Roof racks are hugely important in the 4WD and touring world but must be used carefully and sensibly.
What kind of roof racks do you have on your 4WD?
About the writer...
If it involves four-wheel driving, Aaron loves it. When he isn’t writing for his blog, 4WDing Australia or the Snowys Blog, you’ll find him camping and driving around Western Australia.