Roof Rack for my SUV- some questions

[Noidea87]

My next project is a roof rack for my SUV. I am getting some 3/4" 064 square tubing to use. I'd like to be able to carry around 300 lbs safely up here. Will the attached design accomplish this? I'm still trying to decide if I want to use 6 cross members and cover the sun roof, or leave the sunroof open, and use 5 cross members.

Ideally, I'd like to bend the corners instead of having hard 90 degree corners, but can I accomplish that without a tubing bender? I've seen some videos of people cutting sections out for the bends, but it's always on larger tubing so I'm not sure it would work well on 3/4".

I will be mounting the rack using mounts fabricated for my truck that have been tested by many people and should work well.

Any advice, tips, thoughts?

[Tarmstrong]

I have a set up on my SUVs that has a front and rear crossbar...and a bar that is also in the rear frame mounted trailer receiver tube. I can carry long and very heavy loads that way. The three cross bars are rated at 500lbs each...but I don’t get that high.

The use of the receiver hitch is a great way to get the heavy loads toward that as it is rated higher and can easily handle up to the 500 lbs. And spread the roof load out.

[Welder Dave]

I can tell you that even with 1" thin wall tubing welding is going to cause a lot of distortion. Need to have something heavy to clamp pieces to, to limit distortion. Also need to jump around when welding to lessen the effects. Seems like a simple build until you have to figure out how to straighten it.

[Noidea87]

I can tell you that even with 1" thin wall tubing welding is going to cause a lot of distortion. Need to have something heavy to clamp pieces to, to limit distortion. Also need to jump around when welding to lessen the effects. Seems like a simple build until you have to figure out how to straighten it.

Yeah I haven't tried to build anything with tubing this small. So I'm guessing just doing opposite corners and rotating around the piece welding won't be enough to stop distortion on small tubing like this? That's what I did when welding up my picnic table frame but that was with 2 x 2 not 3/4" My table isn't big enough to clamp the whole piece down to when I'm working

[ezduzit]

It will look like hell if you use square corners. I'd use round tube and mandrel bends to get a nice radius. If you must use square tube, there are simple ways to produce a radius on the outside corners.

[Noidea87]

It will look like hell if you use square corners. I'd use round tube and mandrel bends to get a nice radius. If you must use square tube, there are simple ways to produce a radius on the outside corners.

can it be done with tubing this small though? I've seen videos with larger tubing, but I didn't know if it would work as well with something this thin.

I'd like to use round tube, but I don't have a tubing notcher, and it looks like a pain to do it with a grinder.

[ezduzit]

The better your equipment, the better your results, no doubt. But, with patience, you can produce good fish-mouths with basic tools. I use a roughing end mill on a milling machine to do the fish-mouths. But it can be done with a hole saw on a drill press if you're careful with the setup. Tubing notchers are very inexpensive.

[davec]

Aluminum or steel? I didn't see you specify. I'd think you'd want aluminum for the weight.

[Noidea87]

Aluminum or steel? I didn't see you specify. I'd think you'd want aluminum for the weight.

This is steel, I'm not setup to weld aluminum. and I'm not too concerned about the weight. I think it should weigh around 40 lbs.

Most of the notchers I've found are upwards of $200. I did find one at habor freight for $50 but not sure how well it would work.

[Broccoli1]

use 1" sq tubing.


You can buy 1" rounded corners

https://www.allmetalssupply.com/prod...uare-steel-90/

FYI-
I have the HF notcher- it actually works pretty good iffin' you want to use round tubing.

You do need a good set of hole saws though.

https://www.lenoxtools.com/pages/car...hole-saws.aspx



Dunno if yer close to Los Angeles but I have everything you need

[psacustomcreations]

This is steel, I'm not setup to weld aluminum. and I'm not too concerned about the weight. I think it should weigh around 40 lbs.

Most of the notchers I've found are upwards of $200. I did find one at habor freight for $50 but not sure how well it would work.

How are you going to prevent rust spots or rust dripping on the vehicle? Unless you powder coat it, the rattle can will get nicks and rust pretty quickly.

[Noidea87]

How are you going to prevent rust spots or rust dripping on the vehicle? Unless you powder coat it, the rattle can will get nicks and rust pretty quickly.

I was thinking of having it powder coated, but I may just rattle can it.

[Noidea87]

So I think I have decided to get the tubing notcher and go with 1" round tubing to build this. Lately I have been thinking about mounting my spare up there as well. I will eventually get a new rear bumper and mount my spare there, but while off road I'd like to option to increase ground clearance, and I don't think a 33" tire will fit under the SUV in the stock location anyway.


What I'm thinking about is a 3/16" plate that I could mount to the cross bars with U-bolts so I can remove it when not needed. Then a piece of 2 x 2 square tubing welded to that plate, and a smaller 3/16" plate with studs to attach the wheel. What wall thickness do you think the square tubing needs to be? Would 064 work ( I have plenty of that laying around) or should I got to 1/8"?

[ezduzit]

I would not want the wind noise and drag. Nor would I want the raised center of gravity.

[FlyFishn]

A couple thoughts:

1. I am not sure I would want a lot of weight up on the roof of your SUV alone. Yeah, it is probably rated for some level of roll-over protection so it has to be somewhat strong for that reason, but I doubt it is rated to hold a lot of weight going down the road. I have a 1 ton truck with an 8ft bed and a fiberglass cap (mid-height, about 4" higher than the roof of the cab) that I haul stuff on top of on a pallet at times. I built a frame out of 2x4's that transfer the load from the roof to the floor of the bed, and thus to the frame. The weight on top is no longer "supported" from the structure of the cap - the upright 2x4's take the load and are positioned directly under where the "feet" of the pallet rest (the pallet doesn't even rest entirely on the cross bars of the rack - there are blocks that rest on the cross bar track as the cross bars would not hold the weight, either).

2. Your suspension in the SUV is likely not very stiff. The higher your center of gravity (and the more weight you put up there, even at the same height, the higher the center of gravity you have) the worse the stability. On the 1 ton I have overload springs on the rear axle (SRW, not DRW) and I can get by, but it is still "tippy".

With that having been said - have fun with the project. Go easy on the weight to get a feel for both the stability on the road and the structural integrity of the roof etc. If you sense any flexing you have too much weight.

As someone else suggested - try transferring some of the weight to the hitch receiver.

Or get a trailer and tow it behind, even better.

[John T]

Go aluminum or go home.

.

[bead-boy]

i added a single light bar to the folding windshield of my old Jeep CJ5. The noise increase at highway speed was VERY noticeable. As it was my daily driver at that time I removed it. It never got put back on. All those non-aero bars will make a massive amount of noise. You will never want to drive on the highway with the windows down. If you are mostly off roading, then probably not a big deal.

[duramax-rob]

almost every factory installed have a load limit of 50#. if you drop the headliner and bolt thru one of the roof stiffners, most are glued to the roof, might get more holding force or plate from underneath. auto roofs are made to absorb impact, not from liftoff force.

[sapperb]

1" square tubing by .90 wall..It will be light and can handle more heat than .64 wall...