Roof rack loads - dynamic vs static

Plutonium Kun

I've searched around quite a bit, but I can't find a solid answer to this question, its a slightly tricky technical one.

I'm looking to buy a car soon - the smaller and most fuel efficient cruiser the better, as I don't use a car for day to day use, I want one for weekends away and holiday trips to France. I'm looking at the moment at either a Fabia Estate or a Tiguan. But I do want a rooftop tent for my weekends away - one of these:

Autohome Columbus

These weigh 52 kg. Most of the cars I've been looking at have a rack weight limit of around 75-90 kg in their manuals.

The problem of course is that I want to sleep in the rooftop tent, which means that it will be 52kg + 80kg. For obvious reasons, I hope nobody is driving the car when I'm sleeping up there, so it would be a case of having a static load of 132kg, but a dynamic load (i.e. when driving) of 52kg.

Looking through various camping/motoring forums, and the photos and information on roof tent websites (which frequently show them used on Golfs and even Polos), this doesn't seem to be a problem. Some US sites talk about 165lbs (i.e. 75kg) as the 'usual minimum' for a roof tent. The assumption seems to be that it doesn't really matter how heavy the load is, so long as the car is parked up, the only important thing is that the tent and rack is less than the stated maximum load when your driving.

Can someone clarify this?

EndaHonesty

Plutonium Kun wrote: »

I've searched around quite a bit, but I can't find a solid answer to this question, its a slightly tricky technical one.

I'm looking to buy a car soon - the smaller and most fuel efficient cruiser the better, as I don't use a car for day to day use, I want one for weekends away and holiday trips to France. I'm looking at the moment at either a Fabia Estate or a Tiguan. But I do want a rooftop tent for my weekends away - one of these:

Autohome Columbus

These weigh 52 kg. Most of the cars I've been looking at have a rack weight limit of around 75-90 kg in their manuals.

The problem of course is that I want to sleep in the rooftop tent, which means that it will be 52kg + 80kg. For obvious reasons, I hope nobody is driving the car when I'm sleeping up there, so it would be a case of having a static load of 132kg, but a dynamic load (i.e. when driving) of 52kg.

Looking through various camping/motoring forums, and the photos and information on roof tent websites (which frequently show them used on Golfs and even Polos), this doesn't seem to be a problem. Some US sites talk about 165lbs (i.e. 75kg) as the 'usual minimum' for a roof tent. The assumption seems to be that it doesn't really matter how heavy the load is, so long as the car is parked up, the only important thing is that the tent and rack is less than the stated maximum load when your driving.

Can someone clarify this?

I've been looking at a Tentbox and spoke to them about this very issue.

Your understanding is correct, the quoted loads for roof racks are all "dynamic" so the "static" load limit is way higher.

So much higher that 2 people sleeping in a roof tent is no problem.

How much is the Autohome Columbus roof tent?

Have you considered the Tentbox?

Plutonium Kun

Thanks for the quick reply, Enda.

I hadn't looked at the tent box, Enda, although a quick look at the website looks interesting. I've been sort of in love with the Autohome Columbus since I saw one in a French campsite, the guy who owned it raved about it. They are around 2,500 euro. A lot, I know, but still cheaper than a motorhome or caravan.

EndaHonesty

Plutonium Kun wrote: »

Thanks for the quick reply, Enda.

I hadn't looked at the tent box, Enda, although a quick look at the website looks interesting. I've been sort of in love with the Autohome Columbus since I saw one in a French campsite, the guy who owned it raved about it. They are around 2,500 euro. A lot, I know, but still cheaper than a motorhome or caravan.

I thought the Autohome was expensive alright. The Tentbox is 1,500 GBP so a bit less.

It looks good on the video but it's weight is 78kgs so a lot heavier than the Autohome, which surprises me.

You mentioned the Autohome was 52kgs. Is that correct?

Is it a 1 or 2 person tent?

Plutonium Kun

The small 2 person tents in the Autohome range - the Columbus and the Maggiolina are all in the 52-56 kg range. They have carbon fibre versions that are 10kg lighter, but they are super expensive, nearly 5K. They are significantly lighter than most other on the market, except I think for the James Baroud ones - I think they are out of business (at least, their French website isn't updated, but there are still ones on sale in the US). From what I can see, the Autohome and James Baroud tents use high quality fibreglass and other composites to make very light shells, whereas the other ones in the market use welded steel frames, which are cheaper and easier to make, but far heavier.

While more expensive (the Columbus range starts around 2,300 euro), I'd say they are worth it if you have a smaller vehicle, that weight difference is very significant. If you are using them on a landcover or land cruiser or a truck of some sort, then its probably not that big a difference.