Sagging roof tent

Have fitted the roof tent to the back of my D40 by installing a second sport bar ad connecting them by two rails constructed of double thickness aluminium unistrut. The sport bar and unistrut are holding the weight fine, even with two adults and the nipper up there. However, as you will see from the picture below the tent itself sags quite a bit when folded out:



Have checked the sport bar and its not bending, the unistrut is not bending unduly, especially when we are not on board. Only thing I can think is the suspension is compressing. I'm thinking of trying to put a small bottle jack between the axle and suspension to prevent any flex in the suspension.

Anybody any ideas of other cures or potential solutions to cure this as its a little odd sleeping on such a slope. Never had this problem on my last two patrols, although they were both lifted 4inch therefore perhaps stiffer suspension

[please, no suggestions on what to do with the sagging wife, I know there's no cure for that but to trade her in]

Are you using the ladder as a support?

It looks as though it's not level on the rack aswell. The passenger side looks higher on the rack than the drivers.

Fatboy - no, the ladder is not a support on this tent, if you prop it on the ladder the cantilever joint opens up and you loose the integrity of the floor (if that makes sense)

Jason - the passenger side does look higher and that is what is making me feel like I'm going mad because when I measure from the rail to the tub on each rail it's the same so can only assume its an optical illusion.

Looks like the ladder should be supporting it but can't as it's too long (that happened with mine). I just drilled a couple extra holes in the ladder so it would lock at a lower position and the floor would stay level

+1 on the vehicle bars look level.

It looks like the weight of the extended tent is pulling the whole lot over.
Is it supported in anyway out there
the problem might be that the floor for the bed is actually flexing and allowing it to leant over, but you say is is on a slope, which doesn't make sense. If it was flexing, I would expect body weight to bring it back down.

Would moving the driver side unistruct further out to he side help

I wouldn't be putting anything into he suspension in case you forget about it and drive off.
Perhaps some think planks under the drivers side wheel to elevate it a bit and see what happens.

Very interesting, I'm waiting for delivery of my RTT and it will be set up exactly the same as this on my D22. Although mine is supported by the ladder as others have suggested. I think in your case it's pulling the whole lot over as terryc said. Tight on the LHS and sloppy on the RHS?

Can I ask, was the single aluminium channels not sufficient for the span between sports bars and needed to be doubled up for strength? I am hoping the supplied 2 channels will be enough?

Cheers,
Guido

Guido, yeah, I had to double up the unistrut because it flexed too much for the span, but this isn't the channel on the bottom of the tent, that is running parallel to the tent, the channels you see are running ninty degrees to the ones on the bottom of the tent.

Ahh, I see. I was hoping to not have the unitstrut bars like you but run the supplied channels front to back between sports bars. The tent will fold out the side still. What do you think?

Guido

Ok problem solved, or should I say identified. It would appear that the actual cause of the problem is the sport bars just aren't strong enough and in fact the whole bar is twisting resulting in the horizontal part slopping and the uprights deforming. Very disappointing as I was hoping to add a canvas canopy similar to fatboy. And unfortunately can't really strengthen the sport bars short of adding two more and that is just getting silly.

Back to the drawing board, either get some proper tradie ladder racks with strength (sport bars only rated to 40kg) or maybe buy my welding mate a lot of beer to build me a steel cage for the back and then add canvas over that......but in the meantime will have to abandon the sport bars.

Bought a set of Rhino Rack Heavy Duty Whisper bars and put the tent and these and it all works great. Stays level and sturdy.