Roof Rack Maximum Weight Limits

[Mountain Bru]

Does anyone have any experience with roof rack maximum weights? 

I want to put a roof top tent on my Honda CR-V, so I've been investigating the max weight I can put on the roof. 

According to the car's manual, the max weight you can put on the roof is 80kg. 

Thule's roof racks/bars seem to be rated at 100kg. 

A typical roof top tent is 50 - 60kg, so no problems with the tent alone on the roof. But obviously the point is to sleep in the tent, and therefor add say 2 70kg people, so looking at a weight of around 200kg all together when in use. Some of that weight would go through the tent's ladder though, but still probably more than 80kg on the roof. 

Does anyone have any experience with stuff like this, or know if the rated weights are static or dynamic weight? (I would assume that 80kg is the max load for dynamic circumstances, but can be exceeded if the vehicle is stationary)

I tried to ask the guy at Thule yesterday... He first seemed confused as to why I would want to sleep in a tent on the roof while I'm driving. After I helped him understand that I have no ambition of using the tent while cruising on the highway, he then told me "it's okay because we weigh less when we lie down".... I tried to reason with him, but he was insistent that we weigh more when we're standing than when we lie down, at which point I gave up and figured I'd consult the hub experts. 

Any help would be much appreciated. 

[Super Sywurm]

Obviously you will be over the max weight of both the rack and the car.  I don't have any experience with roof racks, but I wouldn't do it.

[Iwan Kemp]

3 hours ago, Mountain Bru said:

 I tried to reason with him, but he was insistent that we weigh more when we're standing than when we lie down, at which point I gave up and figured I'd consult the hub experts. 

 

 

Edited August 21, 2021 by Iwan Kemp

[Iwan Kemp]

I'm not 100% sure of the weight limit, what I do know is it is less when moving. So, yes you can sleep in a rooftop tent and be safe, but you can't have that same weight loaded up while in transit. 

[Mountain Bru]

7 minutes ago, Iwan Kemp said:

I'm not 100% sure of the weight limit, what I do know is it is less when moving. So, yes you can sleep in a rooftop tent and be safe, but you can't have that same weight loaded up while in transit. 

This is what I figured. If the book states the limit is 80kg, then that would be the moving weight in my mind, and you could technically exceed it if the car wasn't moving. I mean if you load 80kg onto the roof and drive on the highway, surely even just the wind load on the cargo is gonna push you over the limit.

Was hoping someone had already done the experiment without screwing up their car though

[ChrisF]

Google :

suzuki jimny roof load limit

 

 

The driving load on the roof is between 30 and 40kg.  Yet Namibia has many of these Jimny's traveling all over with roof top tents.

 

 

There is clearly a significant difference between the static and dynamic loads ....

 

 

do midnight aerobics counts as static or dynamic loads ?

 

 

 

 

maybe ask on 4x4Community forum if someone had done this with your particular model vehicle

[MORNE]

should be fine if you arent silly while parked. i’d adhere to the moving load limits if you dont fancy your stuff shearing clean off the roof while doing a 4 wheel drift at 120kph haha. 

that said, used to have a proper frontrunner on a 4x4 and those were rated for 120kg, never slept on it but drove with ‘half our house content’ on it from jb to CT when we moved. People basically live on those in the bush lol. they are proper. 

They dont mount on single bolt mounting points like the Thule ones mostly do - if they even are bolt on ones that basically still only give you 4x point loads. i wouldnt bother with those window sill clamping bs ones.

The  proper frontrunner ones spread the load evenly over the length of the A-C and/or even the D pillar in the gutters. 

thule ones are basically good for roof boxes, bicycles, fishing rods and surfboards. i say that someone who has bolt on thule bars on a car that gets loaded up with a roof box to a thumbsuck max of 50-60kg. it works fine..but i woulnt get in it????.

[bertusras]

https://roadmounter.com/roof-top-tents/honda-crv-roof-top-tent-guide/

I was going to ask whether the 100kg limit is per bar or per set, but then found this:

Quote

The WingBar Evo, Probar, and new SquareBar have a maximum load capacity of 220 pounds for a pair.

As for the techy saying you weigh less lying down than standing up, technically he is wrong, but fundamentally he is right. If you're laying down you're spreading your weight over a greater area, so the actual load on each point would be less than you standing up on a single bar for example.

[RiverInTheRoad]

The stated weight limit of 80kg is applicable when the car is moving. When parked that can be exceeded. If you want to add a rooftop tent then I would suggest using a proper roofrack with it. Send a query to Frontrunner and Eazi Awn. Thule load bars are for fishing rods and surfboards. The bar itself is strong but the load is not distributed as well as would be the case for a proper rack. Remember the (proper) rack you would want will also add around 30kg.

Rooftop tents are not as great as they seem. Their main use IMO is for touring with many overnight stops (on flat ground).

[Mountain Bru]

20 hours ago, MORNE said:

should be fine if you arent silly while parked. i’d adhere to the moving load limits if you dont fancy your stuff shearing clean off the roof while doing a 4 wheel drift at 120kph haha. 

that said, used to have a proper frontrunner on a 4x4 and those were rated for 120kg, never slept on it but drove with ‘half our house content’ on it from jb to CT when we moved. People basically live on those in the bush lol. they are proper. 

They dont mount on single bolt mounting points like the Thule ones mostly do - if they even are bolt on ones that basically still only give you 4x point loads. i wouldnt bother with those window sill clamping bs ones.

The  proper frontrunner ones spread the load evenly over the length of the A-C and/or even the D pillar in the gutters. 

thule ones are basically good for roof boxes, bicycles, fishing rods and surfboards. i say that someone who has bolt on thule bars on a car that gets loaded up with a roof box to a thumbsuck max of 50-60kg. it works fine..but i woulnt get in it????.

Yip even Thule themselves don't recommend putting a tent on the window clamp or sliding clamp type of bars. I think it has to "bolt on" bars.

 

[Mountain Bru]

20 hours ago, MORNE said:

The  proper frontrunner ones spread the load evenly over the length of the A-C and/or even the D pillar in the gutters. 

 

3 hours ago, RiverInTheRoad said:

The bar itself is strong but the load is not distributed as well as would be the case for a proper rack.

How do you guys figure that a front runner rack distributes the load differently to 2 bars with a rigid tent base bolts onto them?

I mean there's still the same 4 mounting points, and the same bolts? What makes you say that a full rack would distribute load differently? In my mind, the rack is completely unnecessary seen as the base of the tent is rigidly bolted to the cross bars which are bolted to the rails on the car. Am I missing something? How would bolting the tent to a rack, and then bolting the rack to the same 4 mounting points change anything (apart from adding R8000 to the expenses)?

[Mountain Bru]

7 hours ago, bertusras said:

https://roadmounter.com/roof-top-tents/honda-crv-roof-top-tent-guide/

I was going to ask whether the 100kg limit is per bar or per set, but then found this:

As for the techy saying you weigh less lying down than standing up, technically he is wrong, but fundamentally he is right. If you're laying down you're spreading your weight over a greater area, so the actual load on each point would be less than you standing up on a single bar for example.

If random videos on the internet are to be trusted, this seems pretty conclusive that I'll be fine as long as the tent/rack/bar/combo is less than 80kg. 

Thanks

[Mountain Bru]

3 hours ago, RiverInTheRoad said:

Rooftop tents are not as great as they seem. Their main use IMO is for touring with many overnight stops (on flat ground).

Is this spoken from experience, or just a feeling?

Amongst the people I know, roof top tents are considered to be the best camping solution. Minimum effort for maximum comfort, regardless of what things look like where you're camping. And the minimum "set down" time afterwards. Never heard a different opinion, so I'm keen to hear about the downsides (apart from it basically just being a flippen expensive tent)

[ChrisF]

3 minutes ago, Mountain Bru said:

Is this spoken from experience, or just a feeling?

Amongst the people I know, roof top tents are considered to be the best camping solution. Minimum effort for maximum comfort, regardless of what things look like where you're camping. And the minimum "set down" time afterwards. Never heard a different opinion, so I'm keen to hear about the downsides (apart from it basically just being a flippen expensive tent)

Have you looked at the clamp shell types ? Setup in seconds, and also so much easier to close.

 

 

You may also want to look at a Fredlin hoist ....

 

 

The main downside of a RTT .... the ladder ....

 

 

Dont forget to check the vehicle height with the RTT fitted ... often this takes you past 2,1m height .... so no entry into a standard garage, basement parking, etc ...

[MORNE]

26 minutes ago, Mountain Bru said:

 

How do you guys figure that a front runner rack distributes the load differently to 2 bars with a rigid tent base bolts onto them?

I mean there's still the same 4 mounting points, and the same bolts? What makes you say that a full rack would distribute load differently? In my mind, the rack is completely unnecessary seen as the base of the tent is rigidly bolted to the cross bars which are bolted to the rails on the car. Am I missing something? How would bolting the tent to a rack, and then bolting the rack to the same 4 mounting points change anything (apart from adding R8000 to the expenses)?

 normal car bolt on thule rack (like mine) has 4 x puny single m6 threaded rods/bolts that screw like 10mm into a threaded hole in your roof. The frontrunners basically have a beam/rafter on the gutter that spreads the load evenly...never mind all the extra mounting bolts. but all in all I think it has more to do with shear forces than anythign else. at some stage 60kg + at a certain velocity and side loading will overcoem that little puny bolt and your chit will be all over the highway lol. 

PS, that reminds me...my roofbox has a huge warning inside that says when fully loaded...not to exceed 130kph. 

Edited August 22, 2021 by MORNE

[RiverInTheRoad]

1 hour ago, Mountain Bru said:

Is this spoken from experience, or just a feeling?

Amongst the people I know, roof top tents are considered to be the best camping solution. Minimum effort for maximum comfort, regardless of what things look like where you're camping. And the minimum "set down" time afterwards. Never heard a different opinion, so I'm keen to hear about the downsides (apart from it basically just being a flippen expensive tent)

I have not owned one. Have researched them extensively and consulted many users of them.

I like camping. Especially remote camping. Weight is your biggest enemy on an overland vehicle. RTT adds 70kg at the worst possible location. This is my main gripe with them.