My thanksgiving project

[evldave]

Well, I finally got my Suburban's roof rack built & out of the garage, so now it's on to the hummer's. I'll be posting pics as I get moving forward (won't really start until tomorrow).

Required carrying capability:

Sea Kayak (17-1/2" long, 24" beam)
Mtn Bike, Road Bike
White Water kayak (don't own anything yet, but started this last year and will buy something next spring)
Recovery equipment (hi-lift, straps, shovel, axe, etc)
Air compressor + homemade tank (details to come)
Fishing rod holder (actually a 4" ABS pipe w/screw-on locking end cap)
2 weeks of camping equipment
2 Jerry cans (maybe)
2 water bins (maybe)
horizontal propane tank (hopefully)

I don't necessary have to carry the bikes (already converted my hitch bike rack to mount to the spare tire), but I have a hitch-mounted cargo carrier and it would be nice to put the bikes on top and have daily camping stuff in the rear hitch rack, but I can't do that with the bike on the spare tire.

I'm also going to toy w/a retractable pullout cover for the rear of the rack to cover the rear cargo door area during the rain. I did this on the previous rack for the suburban and it worked quite well on a rainy trip to Alaska last year.


Here's the basic design (I've been going back and forth, so suggestions are appreciated until I start welding).

Width 49". The factory roof rails are 48" on center. To get the edges out to line up straight above the rails, it needs 1/2" on each side. The cross rails will end exactly above the outside of the rails.

Length 8' + some. I'm going to curve the front lower rail to match the curvature of the windshield. The back of the rack will sit at the seam of the rear door and the front will set back an inch or so from the top of the windshield.

Height. The onstar antenna sits 3-1/2" inches above the roof rack rail. I haven't decided if I'll set the entire rack above the antenna or lower it and protect the antenna somehow. That's simple based on the length of the attachments, so I can decide-on-the-fly.


Materials

The cross rails will be 1-1/2" square tubing, either 0.060 or 0.095 (I've got enough of both). My suburban rack was 0.120 with an 11' length and it doesn't flex at all, even under 600+ pound load. I'll likely go with the 0.060 and go with thicker support bars.

The support bars (front to back) will be 1" round tubing, either 0.095 or 0.120 (getting on Friday morning). They will be slid through the crossbars and welded in place.

Floor will be a crosshatch sheet welded to the crossbars and support bars.

Basic design:

There will be 5 crossbars, each 2' apart. 3 suport bars, one centered + 2 on the outsides, but set in from the end of the crossbars ~2". This will give it a combined square-round style I think will go well with the lines of the hummer.

The front will be be a bent piece of 1" tubing matching the line of the windshield. It will be mostly a decorative piece but will also have mounts for the off-road lights and marker lights.

I'll drill 1" holes through the 3 center cross bars and slide the support bars through. The end caps will have a 1" hole drilled through one side of the square (the front side for the rear crossbar, the rear side for the front crossbar) and then welded in place. The ends of the 1" tubing won't go all the way to the back side of the square, which will give me plenty of room to snake wiring through the frame to run all the accessories.

The ends of the crossbars will be capped w/plastic covers, so later I can add side lights for off road and wire them through the frame.

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I'm not 100% sure yet, but I think the top rail will be 5" off the bottom, using 3/4" square tubing, basically mirroring the base later and supported with raisers at each crossbar. The front and rear upper cross rails will be bent to the shape of the sea kayak so I don't have to use my hully rollers (which stick up too high) and I'll use pipe insulation to protect the sea kayak.

I suck at computer design, but have the basic layout done on the computer, I'll make up the rest as I go...

I figure I'll have $100-150 in parts and a weekend of labor. PLUS I'll have exactly what I want that no one else has. Any comments are appreciated.