Roof Bar payload limits

ruplaw · Feb 29, 2020

Hi Folks,

Looking to fit some roof bars to enable a roof top tent to be added to my Discovery 4. Many of the available roof bars on offer quote 75kg payload limit per bar. OK, so assuming two bars that gives 150kg payload, but simple maths says me + wife + tent adds up to ...... more than 150kg. And yet most of the tent suppliers claim two bars are all you need. Short of sourcing a lighter wife, am I missing something here?

Thanks for any input.

Western Slope Rover · Feb 29, 2020

Sounds like you're missing a third bar.

Grahame of the shires · Feb 29, 2020

This is on the standard roofbars/roofrails. Takes me and the wife no problem

leeds · Feb 29, 2020

Roof bars load ratings are given for shall we say dynamic loading, i.e. driving down the road. Static loading they will take a much higher load.

So unless you are going to get a third party to drive your D4 down the M1 at 70mph with you and your wife tucked up in your roof tent you will be fine.

We have fitted many roof tents on two bars without issue.

Now assuming you are going for roof bars which clamp onto the D4 factory fitted rails I would suggest you clamp them as close as possible to where the rails are attached to the roof.

HTH

Brendan

ruplaw · Mar 1, 2020

Thanks for the replies. I think Brendan above may be on to the right answer, it's all about static verses dynamic load limits.
PS: will definitely try and avoid the trip down the M1 whilst actually in the tent on top!

Si Click · Mar 1, 2020

The number of bars you need depends on the dynamic loading and where you are driving it. If you are planning on overland travel with some significant off road sections then I would go 3 bars minimum and ideally 4. If you have 2 bars and one fails you are stuffed; but with 3 bars you just redistribute the load and carry on, with 4 bars you probably don't even need to do that.

leeds · Mar 1, 2020

What tends to kill things are long distances on corrugated roads where things such as self tappers become self untappers

Folding roof tents are typically in the width range of 1.2-1.6m wide compared to the 2.1 m length of hard shell tents. If considering the 4 bar route especially for a folding tent than you might as well consider a roofrack as the roofbar centres will be about 0.3 m. The next discussion would than be welded racks v bolted racks for offroad use.

Two bars are in general more than adequate for folding tents for most peoples normal use.

Brendan

Si Click · Mar 1, 2020

For a small folding tent then a roof rack is indeed a sensible way to go as there will still be exploitable space on the rack. Indeed, that it gives you that space is one good argument for a folding tent. For a hard top tent like mine which would completely fill a roof rack, then 4 good roof bars are a better option as it is easier to fit the tent (the bars can be moved), it is much cheaper and best of all much lighter.

I absolutely agree about corrugations. If there is anything loose or of questionable quality on your truck, then a few days of constant vibration on a corrugated road will reveal it to you.

ruplaw · Mar 1, 2020

Thanks everybody - all good info and advice. At the moment looks like the way ahead for us is a ProSpeed rack with Ventura folding roof tent on top. That should leave the front third of the rack spare for odds and ends. I'll send a photo or two when assembled, and then another one of any broken bits after some off roading........! Planning to tackle the Pyrenees this year.

leeds · Mar 1, 2020

For a folding roof tent you need a flat roof rack without luggage rails. If it is a close fitting rack so you can not easily get your hands underneath to get to fixings you might want to consider something like the Nakatanenga roof tent quick mounting system here

Roof Bar payload limits

ruplaw

Member

Western Slope Rover

Well-Known Member

Grahame of the shires

Active Member

leeds

Well-Known Member

ruplaw

Member

Si Click

Well-Known Member

leeds

Well-Known Member

Si Click

Well-Known Member

ruplaw

Member

leeds

Well-Known Member

Similar threads