Jamboree Rack Design

[SR1355]

After seeing Cris B. inspirational rack design I decided to get off the couch and get to work.

Over the weekend I designed and built a full size mock up for a Jamboree Rack. Rack will be 18X48X4.75 mounted off spare tire mount. Spare tire mount will be relocated outward 1 1/2" and rack was designed to allow 35" tire on spare carrier.

Does anyone know a safe load limit for spare tire carrier. I use it as a step to roof rack right now and it seems pretty stout. My 200# seems to not bother it, I know that with the rack and tire, leverage is going to come into play but still think is should be able to carry a fair amount of weight. I hope to carry two 5 gallon J-Cans and a 58 QT cooler.

I've attached some images from modelling software as well as photochop of rack installed on H3. Plans and cut list are at fabricators for estimate right now.

Any input would be appreciated, I took tailgate apart and looks like connection of spare tire carrier is reinforced.

[evldave]

A few things to think about, I posted some stuff like this on Chris's thread too. I've had my bike mounted to the rear tire mount for more than a year now, so have some experience with this. With 2 bikes and the 33" spare the rear gate will flex slightly at the mounting points even though they are re-inforced. A 58 qt cooler (75 cans) and 2 5 gal jerry cans is about 140# of static weight resting on the mounts. If you do nothing but drive on flat ground I have no doubt this won't be an issue, but I do believe that it will be an issue when off road, hitting bumps, etc.

I'm not trying to rain on anyone's parade here, but I actually took off the bike rack mount because of my concern over the flexing of the rear door. Your design looks real solid, and if I can see in the pics, you might even have two side braces that press up against the door? that would help take some of the load off the mounting bolts, but I still think a rear rack w/spare tire will cause problems when going off road.

If you can make the rear rack, why not make up a roof rack and put the spare up there? I did that, and it eliminates a ton of extra weight on the rear door and I'm sure you could load up that rack with all kinds of cool stuff and still have piece of mind!

my 2 cents...

[SR1355]

appreciate your insight and comments. quick question about your bike rack, did it mount after the spare, resulting in a lever action due to the bike being so far out from the gate. Thanks for the quick math on the weight of the cooler and cans, the rack material weights 56.32# give or take a # or two.

[bjc]

So that last pic is a Photoshop? Damn. Nice work.

[SR1355]

Originally Posted by bjc

So that last pic is a Photoshop? Damn. Nice work.

Yeah, I modelled the rack, set-up camara in software close to actual phote angle then finished it in PS.

Couldn't figure out how to add dirt to the chopped rack.... now that would look good... maybe add the J-Cans and cooler for some fun later...

[evldave]

Originally Posted by SR1355

appreciate your insight and comments. quick question about your bike rack, did it mount after the spare, resulting in a lever action due to the bike being so far out from the gate. Thanks for the quick math on the weight of the cooler and cans, the rack material weights 56.32# give or take a # or two.

Yes, it mounted to the bolts holding the spare (there's pics somewhere on elcova w/the mount), and it did have lever action on the rear gate. After I moved the spare to the roof and just had the bikes on it, it still flexed but obviously not as much. I'd love to have someone stand on the rear bumper w/the bikes on (2 of them) and see how much the rear gate flexes when going over bumps.

As a note, I have beat up my hummer, and gone over good bumps w/the tire and 1 bike back there and there's no noticeable permanent deflection. When you do get this all done, and put in a cooler and jerry cans, see if you can measure a before/after deflection while fully loaded. I'm extra conservative, but if you prove the rear gate can handle the weight, super!

[SR1355]

60 plus views.... no additional comments....

[Demo]

Well, I wrote a long comment but then decided not to post it. Didn't want to burst your bubble.

So here it is, I think that putting anymore weight on the already overwieght rear door is a bad idea. Unless you don't plan on keeping your H3 long, I predict that your rear door will begin sagging and will require readjustments becoming more and more frequent. I would put my time and effort somewhere else. Additionaly I think it will make access to your roof rack much more difficult. Not to mention the concern you have of pushing the tire out over and inch. Save your money and get a good adventure trailer. My two cents, hope it helps.

[Demo]

Oh yeah, your design looks great, I just don't think the vehicle is made to handle it.

[evldave]

I noticed in your pic you already have a roof rack. Why not just put the spare up there and mount the rack to where the spare mount goes? You could load it up real good and not risk hurting the rear door. Get rid of the whole cone-shaped thing and clean up the back and it would look real nice!

[SR1355]

While I agree it may be too much... I would think that the engineers at GM would know that a company coming up with something like this is going to happen and they would provide extra capacity in the design... maybe not. I guess the only way to find out is to do it and see what happens... could be an expensive experiment.

The saga begins...

[HummBebe]

I think its going to look great!!!

I wouldn't over load it though. A couple of Jerry-Cans would look slick on it. But I've always been cautious about adding weight to any door.

I am impressed with the design.

[Demo]

I think evldave has a good idea. You could make a two tier rack for the back door and put the spare on the roof. The Iceland conversions I have seen remove the spare (hard to carry a 38+ spare) and make a cargo box for the back door. Either way you clearly have skills, and I can't wait to see what you come up, when I see it at Moab!

[SR1355]

Originally Posted by HummBebe

I think its going to look great!!!

I wouldn't over load it though. A couple of Jerry-Cans would look slick on it. But I've always been cautious about adding weight to any door.

I am impressed with the design.

Thanks, hoping to have it or some other design complete for the Moab trip.

[SR1355]

Originally Posted by DemoDaddy79

I think evldave has a good idea. You could make a two tier rack for the back door and put the spare on the roof. The Iceland conversions I have seen remove the spare (hard to carry a 38+ spare) and make a cargo box for the back door. Either way you clearly have skills, and I can't wait to see what you come up, when I see it at Moab!

Maybe 4 J-cans below and trail rack above, it would be an easy mod to the rack currently designed.

[Hunner]

Originally Posted by SR1355

While I agree it may be too much... I would think that the engineers at GM would know that a company coming up with something like this is going to happen and they would provide extra capacity in the design... maybe not. I guess the only way to find out is to do it and see what happens... could be an expensive experiment.

The saga begins...

Interesting observation since the design on Cris's thread starts with a rack pictured and offered by Amstar which is AM General which is how all this Hummer stuff got started. I wonder if they considered that it would really work or not?

[Demo]

prolly thought about it just as much as they thought about putting an I-5 with malfunctioning heads in the H3 .

Or better yet, selling products through the stealerships only.

[Hunner]

Or the skid plates that are not wide enough to cover the shock mount hanging out there in space.
There site is now underconstruction.
The new owners of the local dealership actually showed me a book today from them but all I saw was high dollar H2 stuff. All the mods for H3's that were on the site are not in their book. They have been advertising for over a year and have not made most of that available in my area.

[excel25]

Why not use the same top and attach it in your trailer hitch receiver and let it rest on your spare tire, That would take stress of door and still be out of the way.

[garnerbiker]

We need to rip off the factory rear bumper and put an XJ style durango bumper. Then, you can have the everything you want atached to the rear bumper and still up high for wheeling. But NO, no one has made something like that yet unless it's all fabed up. It would be great to have the 2 cans, high lift, and spare on there off center and up a bit higher. Also, you can yank on that bumper as hard as you want.

http://www.durango4x4.com/rearbumpers.html

http://www.durango4x4.com/images/gallery/Elliot02.jpg

We need to make something similar to what they have and keep it low profile and close to the truck and not weigh 500#'s