Let's talk awnings, racks, and dynamic load limits

[trailRunner]

I've searched high and low and cannot seem to get a good source of information on this topic so I'm coming to the pros.

Weight: Some manufacturers load-rate their roof rack systems, others do not. I've ordered a Rhino-Rack with a 145lb dynamic, off-road weight rating, which I'm using as my limiter. It says to also factor in the weight of the rack itself, so I'm actually only working with about 100lb limit. Already this seems ridiculous to me. The same company offers a rail upgrade system that increases the static (non-moving) load rating, but the dynamic load rating only increases to 108lbs.

Most awnings are 40-50lbs. My other gear is 60lbs. How do people carry all of their stuff on roof rack with numbers like this?

So I'm left with wondering: do awnings factor into weight limit differently? Since they sit over the rails rather than the crossbars, is their weight factored in the same way?

Secondly: Are there any numbers around ratios for mount lengths of awning length to roof rail length? I've definitely seen some overlanders with awnings that stick out past their racks, but what percentage can stick out past the mountain rails? 1/3rd?

Given that many folks fab their own stuff and only some of the manufacturers actually provide adequate documentation, maybe I'm overthinking this whole thing. But that's a lot of $ to leave to chance. I'd love to hear what you all think.

 

[1Louder]

Most rack weight limitations have to do with how the rack mounts to the vehicle and not the rack itself. I believe the weight recommendation limits are create by the vehicle manufacturers.

For example:"
* Warrior Recommends not exceeding the following weights:
Stationary: 600 lbs
On-Road: 400 lbs
Off-Road: 150 lbs"

The further you stick the awning out the more likely you will rip it off on a tree, rock wall, etc. The only real limit is you want 2 bolts/u clamps on each mounting point. So it just depends on how big the brackets are and how many holes they have.

 

[Trail_pilot]

Most factory roof rails are only rated at about 150 lb to begin with from what I have seen. I feel like its more of a liability thing than anything else, but I am not an engineer nor do I claim to know much about static or dynamic load ratings and where the numbers come from. I am going to keep an eye on this thread because I am planing on building a roof rack system for my jeep in the near future and some Ideas on weight ratings will be goo d to know.

 

[Charles M]

I would guess the limits are based on how it will affect the center of gravity and many of the things noted above. My Awning is mounted to three custom fabricated cromoly cross bars they are very rigid.

 

[Daryl 32]

Most rack weight limitations have to do with how the rack mounts to the vehicle and not the rack itself. I believe the weight recommendation limits are create by the vehicle manufacturers.

For example:"
* Warrior Recommends not exceeding the following weights:
Stationary: 600 lbs
On-Road: 400 lbs
Off-Road: 150 lbs"

The further you stick the awning out the more likely you will rip it off on a tree, rock wall, etc. The only real limit is you want 2 bolts/u clamps on each mounting point. So it just depends on how big the brackets are and how many holes they have.

Agreed.

A another HUGE factor in factory load ratings is liability concerns. I use to design truck accessories which included roof racks and construction racks. Our construction racks were capable of "holding up" 500 lbs or so, but not safe to do so while driving at speed. So we rated them, in firm words, at 150 lb s on 2500 HD and 3500 HD trucks. And like 75 lbs on 1/2 tons, do people over load them?

If an owner were to load his rack with more then 150 lbs, drive like an idiot down the highway and need to make a sudden move to avoid hitting someone. Causing them to rollover and hurt or kill someone. There are lots of lawyers out ready to go after the "big money" of the manufacturers of every bolt on part the person had on their vehicle.