Critique my rack design...homebrew Jeep rack

[kodiak1232003]

here's some pics

here's the rundown:

1. 3-4 thule load bars
2. 1 sheet of 3/4 or 5/8's plywood (coated with bedliner or similar)
3. to AT can carriers or similar w/ 5gal water cans
4. large load carrying space w/ tie-down eyelets
5. provisions for carrying my sand/bridging ladders
6. space in front of can carriers for light set.


expenses
1. towers.................. $40.00
2. load bars.................$75.00
3. plywood.................$10-15.00
4. can carriers..............$75.00-80.00
5. hardware..................$20-30.00
6. bedliner stuff.............$50.00
_____________________________
total............................$270-300.00-ish

+water cans ($20.00 each) and lights ($??.00)


basically i'm gonna mount a rack permanantly to our jeep.

I got a quote from a fabricator friend for around $400.00 to do a rack not unlike the ones seen on defender 90's and 110's.

like this:

or this:

I'm just exploring other options that might be
1. lighter in weight
2. less expensive.
3. having less wind resistance/noise


one thing to consider is that we are a family of four. so we only have the sides of the rig and the rear load area(good sized,usually swallows cooler and food)

 

[Mercedesrover]

Am I the first to say roof racks look cool but really aren't that practical? The first trip I took with my Rover I loaded all I could up top. I had two boxes full of gear, a spare tire, empty water jugs and God knows what else up there. At least 150lbs. I was a rookie and thought that's what you did. Over the years I've learned to limit what goes up on the truck and the trips have been all the better for it. The rack is now half the size and mounts directly to the roof skin instead of to the gutters and off the roof. This helps immensely with wind resistance and fuel economy. All that goes on the roof now is one empty fuel can, two camp chairs, tent and laundry bags and the grille/stove. There is perhaps 50lbs up there and nothing taller than about 8 inches. Everything else goes inside the truck as well as two to people and two dogs and we carry enough gear to travel indefinitely, all inside a short wheel base truck. Pack light, pack lean and keep the weight off the roof. The truck will be much more stable and much safer!

Here's a picture of the truck on it's first trip:

Here's the same truck in this year's trip:

Jim

 

[Schattenjager]

Am I the first to say roof racks look cool but really aren't that practical?

They can in fact be UBER handy - but as mentioned above - it requires a certain measure of skill to load one properly.

Your design looks great - just keep in mind how it is going to handle on the road loaded up and how any weight up top might limit your line off road.

I carry nothing more substantial than sleeping bag, tents, and Christmas trees on my roof rack...

 

[Grim Reaper]

Am I the first to say roof racks look cool but really aren't that practical? The first trip I took with my Rover I loaded all I could up top. I had two boxes full of gear, a spare tire, empty water jugs and God knows what else up there. At least 150lbs. I was a rookie and thought that's what you did. Over the years I've learned to limit what goes up on the truck and the trips have been all the better for it. The rack is now half the size and mounts directly to the roof skin instead of to the gutters and off the roof. This helps immensely with wind resistance and fuel economy. All that goes on the roof now is one empty fuel can, two camp chairs, tent and laundry bags and the grille/stove. There is perhaps 50lbs up there and nothing taller than about 8 inches. Everything else goes inside the truck as well as two to people and two dogs and we carry enough gear to travel indefinitely, all inside a short wheel base truck. Pack light, pack lean and keep the weight off the roof. The truck will be much more stable and much safer!


Jim

That's some good info.

I am in a space jam and reluctantly looking at a rack on my 4Runner. I can't put a full size spare (33) in the stock location. Hangs down too far and it doesn't fit between the diff and the trailer hitch bracket. My "House" battery for the fridge and accessories is a beast at 125lb and it will tuck up where the spare was keeping the CG low.

I really would hate to load a spare on the roof especially a Muddy one from a tire change so I am building a spare tire rack on the back and it will also have a mount for a NATO can agian trying to keep CG down.

My problem is just lack of space for a few items including my sand ladders (mine are the fiberglass grate material), shovel, Ax and HiLift. All stuff that once its used will proably be dirty and I don't want it in the truck. I really hate the added wind resistance because that little 4 Banger is already taxed especially if I am pulling the trailer. Going to make a wind deflector like you see on the Nissan's and Yakima racks to try to clean up the airflow.

To the Thread starter... skip the plywood. You will eventually have water problems with it and it will eventually end up being a big sponge. If you must use wood then use a rot resistant plank like Cedar or Teak.

I have been looking at materials and I am leaning towards having a sheet of 1/8 thick Aluminum cut into 4 inch wide strips spaced 2 inches apart to make the floor surface. Then cross brace the frame to support it. The sand ladder will slide in and become the floor when not in use if I need to stand on it. Since I will have very little on the rack if I need the sand ladders it will not be to much of a problem to unload to get at them. The shovels and HiLift will be mounted so they will not interfere with the sand ladder being pulled out.

As far as lights go...If you wheel in the woods....they are trail fodder. They will get destroyed. Make a way to protect them or have the m lay back so they don't snag branches when not in use. From a Legal stand point you cannot run any lights uncovered higher then about 40 inches on the Hwy in most places. So if you want to use them on the road he need to be down on the bumper to be legal for road use.

 

[TeriAnn]

Pack light, pack lean and keep the weight off the roof. The truck will be much more stable and much safer!
Jim

Best advice you will ever get for roof racks! Top heavy rigs just tend to tip over too easily, they sway more if you have to make a quick directional adjustment on the highway and fuel mileage will suffer. The roof is the last place to put fuel cans. Oh and a plywood sheet will affect airflow over your vehicle. I recommend either 1 inch cross bars or 1 inch cross bars plus expanded metal so as to have minimum interference with airflow. I have an expanded metal floor because I stand up on top of my roof rack with a tripod to take pictures. My rack is the width of my vehicle and 4 feet long.

That said I should practice more what I preach and not as I do. I keep my rear interior empty for a Large Irish Wolfhound and I tend to bring a major repair station with me. Without the hound all the non potentially toxic stuff would go inside at floor area.

For 2 week or longer runs (full roof rack load) my rack carries:

• shower tent
• 18" X 18" sheet of half inch plywood
• one jack stand
• 5L can of solvent
• empty 5L can for used solvent or oil
• 5L can of gear oil
• aluminum 3 gal propane bottle (my built in tank always goes dry while cooking dinner)
• 3 gallon bottle of drinking water (in case my built in water tank runs dry)
• camp chair
• plastic hand crank washing machine
• 2 tote boxes

Tote box #1 carries the icky stuff: grease pump, gear oil pump, hydralulic bottle jack, Series Land Rover mechanical bottle jack, can of grease and a plastic funnel for pouring used oil & solvent into the 5L waste fluid can. The box could stand to be 1/4 its size but I haven't found a good rugged light weight waterproof replacement box the right size. So the box is mostly empty.

Tote box #2 carries misc camping stuff I do not use every day: water hose to use for filling my built in water tank if needed, shower pump & head for my shower, hose to connect spare propane bottle, large nylon tarp, tent stakes & rope in case I wish to erect an awning, spare water filter cartridges and a long extension cord in case I find myself camping near an outlet (I have a plug at the back of my vehicle & built in 3 stage battery charger to keep the second battery topped off and can run the refrigerator off 120V. I also have a duplex mains outlet inside so I could power something without bringing the cord in through a window)

The washing machine and spare propane bottle stays home for trips less than 2 weeks. For trips less than a week, the shower tent & box with the tarp & such stays home (I settle on sponge baths). If I'm traveling alone the chair may stay home since I camp inside my vehicle and don't use it unless I'm joining others at a camp fire.

Only my maintenance & repair gear always comes along. On the other hand, last time I used the jack stand was to replace a front axle on the trail and I just now upgraded to much stronger front axles. So maybe I wont need it anymore.

Sorry I've digressed with my example. I suggest putting your extra fuel cans on the tail gate, don't use a solid floor and keep roof rack weight as low as possible. Try not to be like me, carrying lots of junk up there.

 

[kodiak1232003]

Am I the first to say roof racks look cool but really aren't that practical? The first trip I took with my Rover I loaded all I could up top. I had two boxes full of gear, a spare tire, empty water jugs and God knows what else up there. At least 150lbs. I was a rookie and thought that's what you did. Over the years I've learned to limit what goes up on the truck and the trips have been all the better for it. The rack is now half the size and mounts directly to the roof skin instead of to the gutters and off the roof. This helps immensely with wind resistance and fuel economy. All that goes on the roof now is one empty fuel can, two camp chairs, tent and laundry bags and the grille/stove. There is perhaps 50lbs up there and nothing taller than about 8 inches. Everything else goes inside the truck as well as two to people and two dogs and we carry enough gear to travel indefinitely, all inside a short wheel base truck. Pack light, pack lean and keep the weight off the roof. The truck will be much more stable and much safer!

Here's a picture of the truck on it's first trip:

Here's the same truck in this year's trip:

Jim

hey Jim,
thanks for the input...

here's the stuff that would be going up there
1. watercans(if i can put them somewhere else i will...need em here in the desert, though)
2. camp chairs
3. camp table
4. double trail stroller (only on occasion)
5. firewood
6. sand ladders

that might be about it.

 

[kodiak1232003]

That's some good info.



To the Thread starter... skip the plywood. You will eventually have water problems with it and it will eventually end up being a big sponge.If you must use wood then use a rot resistant plank like Cedar or Teak

do you think this would be a problem even if i bedlined it?


As far as lights go...If you wheel in the woods....they are trail fodder. They will get destroyed. Make a way to protect them or have the m lay back so they don't snag branches when not in use. From a Legal stand point you cannot run any lights uncovered higher then about 40 inches on the Hwy in most places. So if you want to use them on the road he need to be down on the bumper to be legal for road use. good stuff

great advice, thanks.

 

[86cj]

I looked at a RTT for the LJ and the options to mount it and decided the weight of the rack itself is a huge part of the equation so your idea is a good one.

I know your weight plans are less than mine but make sure it mounts to the body or frame at all corners. The hardtop is not very thick or sturdy but is expensive.

Some people do mount thule type racks on them, just remember if they bump anything the mounting area of the hardtop will be damaged.

 

[BC Explorer]

The first time I bought my roof rack for my XJ (1.5 years ago) I loaded the hell out of it ! , I then got in the truck and realized it was empty inside !
Now I carry my spare tire, tall jack and shovel and thats about it up there.
Now the dam rack is to big.
I found by packing differently I save a ton of room and weight and can go on trips for 2 weeks and still not need to put anything else on the roof rack.

 

[Grim Reaper]

great advice, thanks.

I just don't like plywood. Its heavy.

Have you seen the rack slee sells. This is sweet. I am trying to find the extrusions to make something like it.
http://www.sleeoffroad.com/products/products_roofracks_details.htm

 

[jim65wagon]

I just don't like plywood. Its heavy.

x2. The rack I built for the Tun has a 3/4" ply marine grade floor. The ply alone weighs nearly as much as the rack itself...I wish I had access to some aluminum.
Camping with kids nearly doubles (even though they are half the size of an adult) everything you must bring on a trip...food, beds, entertainment. Kids require much more gear and cannot get by on less without major disruptions in the experience. As for the rack, try to go as light as possible with the build, (ie aluminum vs steel; and 1/2" vs 3/4" ply if you go that route), and lots of measurements and graph paper. It's fun to spend a winter drawing possibilities, spend a spring building, then spend a summer camping saying "I wish I woulda..." But, hey, a simple cutoff wheel, some grinding, a bit more metal, and it'll be perfect next year; right?

 

[ntsqd]

Re: Plywood. 3/4" is excessive. I used 1/2" with spans one way of 48" and the other of 53" They are bolted on all 4 sides, but there are no stringers underneath - only a perimiter frame.

I used mine as a desert race viewing platform, so it saw a lot of walking on.

If you do go with plywood I would suggest using a compatible primer thinned with Penetrol first, followed by white marine boat paint. If walking on it is thot to be even somewhat common then I would additionally suggest adding the deck surface traction additive to the paint for the top surfaces.

If you do build one I would not add any sort of side/end rails. What you put up there wants to be secured enough that they shouldn't be necessary, and when there isn't anything up there you really don't need the extra drag.

As far as lights go, first consider the likely glare on the hood. Positioning of overhead lights is somewhat critical to keep any glare from reflecting off the hood into your eyes.
If you make the mount pivot then you can fold them flat when not needed. If they fold back and you use gas springs to push them fwd then any branches encountered will hinge them back & once clear the gas springs with push them back into place.

 

[RoundOut]

I agree with the others that suggested to ditch the plywood. If you require a floor, use steel or aluminum expanded metal in a thickness that suits your support requirements. I bet the bracing and expanded metal would weigh less than half the weight of the plywood and coatings required to keep it dry. You could rhino-line, linex, or herculine the expanded metal for traction, too. It would still weigh just a fraction of your plywood option. If I were building what you suggest, I'd use aluminum expanded metal and put the traction stuff on it. It would never oxidize in any way, if you coat both sides.

There's my $.02.

 

[ntsqd]

Density: Plywood vs Steel or Aluminum

Above comments made me wonder about this, so I dug up some numbers & ran a few calcs just to see how it worked out.

Density of Plywood tends to be the same as that of the base wood species. In Pine that is 500-650 kg/m^3
(http://www.australply.com.au/ti_char.html)

Density of Steel is 7850 kg/m^3
(http://hypertextbook.com/facts/2004/KarenSutherland.shtml)

Using one of my rack's panels as a sample (53" x 48" x .5"; 1.219m x 1.346m x .0127m) I get a volume of 0.0208m^3
Using the density of pine plywood I get 10.4kg-13.5kg minus any mass added by paint etc.

For the same size panel in steel one would need additional stingers for support since the sheet doesn't have any stiffness or strength in that direction. Ignoring that for the moment, my choice for panel thickness would be either 12 gauge(.1046") or 10 gauge (.1345").
That yields a volume of .00436m (12gga.) or .00561m (10ga.)
Using the density of steel I get 34.2kg or 44kg
Keep in mind that we still need to add structure under the steel.

I don't see steel being anything close to the lightest alternative, even with paint on the plywood.

Density of Aluminum: 2700kg/m^3
http://www.allmeasures.com/Formulae/static/materials/2/density.htm

Running the sheet steel calcs using sheet aluminum:
11.8kg or 15.147kg
This is closer to that of plywood, but we still haven't added the structure needed for it to be stiff enough to walk on. I have walked on the plywood w/o any additional structure.

Food for thot.

 

[kodiak1232003]

I agree with the others that suggested to ditch the plywood. If you require a floor, use steel or aluminum expanded metal in a thickness that suits your support requirements. I bet the bracing and expanded metal would weigh less than half the weight of the plywood and coatings required to keep it dry. You could rhino-line, linex, or herculine the expanded metal for traction, too. It would still weigh just a fraction of your plywood option. If I were building what you suggest, I'd use aluminum expanded metal and put the traction stuff on it. It would never oxidize in any way, if you coat both sides.

There's my $.02.

while appreciated, i realized why all of the responses i'm getting are a bit off
as far as flooring...expanded metal isn't really an option

totally my fault...


one of the main reasons for the design,
as stated in http://expeditionportal.com/forum/showthread.php?t=7759

is to shade the roof here in sunny (and deserty) california


i've checked on the price of sheetmetal(aluminium sheet and checkerplate)
and its about 100-200.00...ouch!!!


sorry for the confusion....Is there any option between the $$$ of plate metal and the relative cheapness of plywood?

its hard for me to think that a marine grade ply with bedliner sealing it would have trouble with socal weather.