Pajero NT Roof Racks full length

[Alexey2357]

Thank you guys. I did not think about the center of gravity. I knew that it is not great to put onto the roof, because the center goes up and car gets unstable. But when I was thinking to put bikes onto the roof I did not think about that.

[alanymarce]

The problem with a bigger rack area is the tendency to use the entire space.



Recognising the high labour rate in Australia, what we did would have been more expensive in Australia, however - we built a rack designed to fit the existing mountings and which ignored the above comment - however we are careful to stay within sensible loading. When we carry a second spare wheel/tyre it's horizontal and in the front of the rack hence more or less central (fore and aft) on the vehicle, sand ladders & lightweight shovel - not much weight; and camp chairs. Most of the time that's it. However, for the very few occasions when we need extra fuel we put fuel cans on the rack - this is the only time we're close to maximum load for the rack, and it does increase the height of the CoG so we take this into account and transfer the fuel into the main tank as soon as we can.



PS: welding aluminium is not easy...

[Alexey2357]

The problem with a bigger rack area is the tendency to use the entire space.

PS: welding aluminium is not easy...

I have made decision - I'm not using aluminium racks event if it is manufactured because of fatigue.
Not cheap, you can't take as much as you want and not sure for how long I can rely on them.

[Dicko1]

Guys, where 80-100kg limit is coming from? Is that coming from Pajero? I saw an ARB roof racks have limit 200kg.
If this is the case then I really not sure if it worth spending the money just to karry 67kg(off road limit).
Right now I easily can carry these 70kg in a box + 2 metal bars I have.

This subject has been done many times. Refer to the picture below and note what is said.....limit is the lower of any figure supplied by vehicle manufacturer or roof rack manufacturer. Steel is still used in some roof racks as it is stronger than alloy and way less prone to cracking than alloy. Big disadvantage is weight. Best idea I,ve seen for roof racks to carry a lot of weight is a full length rack extending over the front bonnet and supported by legs mounted to front bullbar. Normally seen on troopies or toyota wagons when I lived in the top end.



In a nutshell....do not exceed 80kgs!!

[old Jack]

When it comes to strength of materials it really depends on the alloy of the base material. A good quality aluminium roof rack will be lighter, stronger and more durable than a mild steel roof rack, it will just cost much more!

Iron is the base metal and it has carbon added to it to make steel, this makes the iron stronger but also heavier. The more carbon the higher the strength of a steel but there is a limit before the steel becomes too brittle. Other metals are also added to steel to improves its mechanical properties of strength, corrosion resistance, weldability, durability, ductility, malleability, the list goes on. Small amounts of Nickel, Chromium, Molybdenum and other minerals can be used as alloying agents.

Aluminium is the base metal and in its purest form, it is very soft and weak but incredibly lightweight.
When other metals and minerals are added in very small amounts to make an aluminium alloy the mechanical properties of the aluminium change radically, strength and durability are increased to the point where the strength to weight ratio overtakes that of many steels. Copper, Magnesium, Manganese, Silicone are just a few of the alloying agent used. Aluminum alloys can go through a further process of heat treatment and depending on the type of heat treatment this will change the mechanical properties of the alloy even further.

It is about the selecting the correct material for the job and this is where engineers and metallurgist come into it. This is the science of material selection!

Unfortunately most time the accountants and sales & marketing people get involved and want to reduce costs because the customers and the market do not want to pay for the best material so a compromise must be made.

The only place where compromises are not made are in the aerospace and aviation industry.
Joe Average does not want the plane he is sitting in to fall apart around him at 12,000m high and doing 600kph!
NASA certainly do not want their spacecraft failing because they used the wrong material for the application.

There is a price for performance and safety.

OJ.

[insect_eater]

I have made decision - I'm not using aluminium racks event if it is manufactured because of fatigue.
Not cheap, you can't take as much as you want and not sure for how long I can rely on them.

I may be mistaken, but I thought that the failure point on the Pajero was the steel roof (cracking at the OEM rail mount holes), regardless of the material from which the roof rack is made - that is, the roof is more likely to break before the rack?