Roof Racks????????

[Sullyman]

Was thinking about getting a rooftop tent setup....however, a friend of mine rolled his land cruiser and the entire cab was crushed on a slant only leaving room for his wife's head. When the insurance adjuster came to see it he mentioned that roof racks are not good for most 4 X 4's

He said the channels and the pillars below where the rack bolts on ends up with metal fatigue from the opposite pitch as the vehicle moves back and forth. As the vehicle pitches right the rack pitches left and ends up like trying to break sheet metal by folding back and forth.

Any thoughts anyone? Anybody out there heard of this? don't want to install roll bars.

[Evo]

Very strange. Haven't heard of this myself.
A good rack should flex with the vehicle body.
I have a steel full length rack on mine and no issues at all.
Might have been an unlucky event.
Just reading your post again, the rack bolts into the roof channels more on top of the roof, or clamps to the gutters along the edge of the roof?

[Clunk]

Sounds plausible....... There's always going to be a small amount if flexing and shifting going on somewhere, hence the reason for the body sitting on rubber mounts.

But having said that I think you'll be just fine to have a rack and roof top tent up there and have no issues at all.
I reckon the best racks are the ones with the bars that run the full length of the gutter, helping to spread the weight more evenly.

Just remember that your roof/ gutters are only designed to carry 100kg including the weight of the rack.

MC app sucks big hairy ones!!!!!!!! Having to delete and reinstall everyday........

[Drewboyaus]

Sounds plausible....... There's always going to be a small amount if flexing and shifting going on somewhere, hence the reason for the body sitting on rubber mounts.

But having said that I think you'll be just fine to have a rack and roof top tent up there and have no issues at all.
I reckon the best racks are the ones with the bars that run the full length of the gutter, helping to spread the weight more evenly.

Just remember that your roof/ gutters are only designed to carry 100kg including the weight of the rack.


What he said and:
1. Your mate had a Toyota!
2. Get a top quality aluminum rack
3. Don't overload it. Mainly use it for lighter bulky stuff, keeping heavier kit lower in the vehicle improving your centre if mass and reducing the chance of a rollover.
4. Your mate had a Toyota!



Tip tip tip......tap tap tap....

[june]

clunk says roof/gutters can take 100kg. I could be wrong here but I think depending on brand of vehicle loads on roofs would vary. I have a fibreglass roof top tent with 2/ 60 watt solar panels and 5 rhino roof bars. total weight including roof bars with 2 people sleeping weighs 267 kg. the 5 bars distribute the load and also makes the tent strong when on corrugated roads. 5 bars might be a over kill but have had no problems.

[Clunk]

clunk says roof/gutters can take 100kg. I could be wrong here but I think depending on brand of vehicle loads on roofs would vary. I have a fibreglass roof top tent with 2/ 60 watt solar panels and 5 rhino roof bars. total weight including roof bars with 2 people sleeping weighs 267 kg. the 5 bars distribute the load and also makes the tent strong when on corrugated roads. 5 bars might be a over kill but have had no problems.

Theres another thread in here somewhere on this subject which explains the whole thing alot better than I can, I'll see if I can dig it out............. it's to do with static weights, which is where your 267kg will come in to play and dynamic weights for when youre on the move and thats when your likely to have approx 100kg on the roof

[Clunk]

here's a couple of threads to look through on the subject

http://www.nissanpatrol.com.au/search-results.html?cx=partner-pub-3013365475430909%3A8470100594&cof=FORID%3A10&query=roof+weight+limit&submit.x=-1363&submit.y=-174

[threedogs]

A member here not long ago had the back of his near
new Patrol torn off due to a CR%P fitting rack. He was not a happy man.
I made my own "platform" and bolted it to some aero Rhino racks, will
built in light bar and awning brackets. works for me, nice and light too.
I know a few who have gone done the same path as June fitting Decent roof bars {racks}.
I'll be fitting another for the rear awning only 1.6 mt wide

[MudRunnerTD]

Engineering wise there is a "dynamic" limit and a "static" limit.

The dynamic limit is the weight that the vehicle manuf will allow for in his design that can be carried on the roof before handling is adversely affected by the raised C of G. This figure can be suprisingly low EG 100 or 130 Kg's has been mentioned already.

The static limit is considered the amount of weight the roof can support without damage/collapse and is rarely specified by a Manuf.

Obviously there are so many variables in each scenario that it almost becomes a best guess by the relevant engineers because they have no control over the owners other mods (esp lifts) or how they pack the car.

Therefore Vehicle Manufacturers stated limits are normally considered dynamic IE any GQ/GU will carry a poo poo load on the roof BUT at the risk of falling over at the first corner

Roof Rack Manuf will normally state a static load but add a proviso not to exceed the manuf load.

Bottom line is that it is all a case of CYA or someone will apply a stupid interpretation, do an 8 inch lift, pack 5 jerries, two spares and a toolbox on the rack, do 110 KPH down the road and after smearing themselves and their truck over the countryside at the first corner will then attempt to sue you're rrse.

A roof top tent, rack and bit of other light kit is fine "dynamically" as you will be under the Manuf roof limit when driving and when parked up assuming a quality roof rack of say 4 mounts per side or full gutter rail then a couple of average adults should also be quite OK.

I certainly have yet to see the gutters collapse or a Patrol on it 's side in a camping ground when the occupants have moved around in a roof topper

^^^^ That Bloke knows STUFF! ^^^^

[cgm]

I don't quite know what the insurance adjuster was trying to say, but there is a lot more flex in most 4x4 bodies than I would have expected. I had a home grown full length steel rack on my Trooper (Jackaroo) and a couple of times I broke a bolt in the back corner I think because it wasn't flexing as much as the car body.

On that vehicle it had captive nuts under the black strip (set of two nuts in 3 locations on each side). I made a side rail down each side (out of a piece of angle iron) and fixed it to the 3 locations. Then sat the rack over that and it was the bolt between the rack and angle that broke a couple of times. Over a period of about 2 years there were small cracks showing around most of the nuts where they were fixed into the roof. I don't think that method of attaching it was up to the task for such a full rack. Having said all that I think that is more to do with whether the rack would be fixed strong enough or cause problems on the long term. I can't imagine that would affect the strength of the vehicle in an accident.

Having full length gutters is one of the things I like about the Patrol (although, look at the new Y62 - following the Toyota lead again)

[Evo]

Reading all this, to me, it hasn't really got much to do regarding the structural integrity or load bearing characteristics of the vehicle gutters and/or pillars with relation to the amount of load on a roof.
It is more regarding the raising of centre of gravity and the effects that has on the handling characteristics of a vehicle.

The rack I have is rated to hold 150kg, obviously I wouldn't be putting that on my troll if it couldn't take it, but I have read in Aus 4x4, and have spoken to a few reputable roof rack suppliers, and patrol gutters are factory rated to take up to 150kgs dynamic load (although can handle more), up to 250 static load. Once you start going 300kgs+, stress fractures will appear along the seam of the gutters and that's the end of it.
So, when parked, sleeping up top, or using it as a decking, no problem, but be careful on overloading for the drive.

Evo

[threedogs]

250kg plus up top going to the TIP or doing the CSR is just asking for trouble'

Pack right and pack SMART I say,

Lay it all out put your heavier items low down in your patrol, keeping the lightest items for on the roof.
swags, a spare wheel/tyre combo and maybe a jerry or two but keep it to a minimum.
Try to keep your CoG, centre of gravity as low as possible.