Where to put the weight? Rear bumper mounts vs Roof Rack

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Bob Berryhill

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Newbie to the overland world (I've entered my intro) and starting to build out a 2014 JKU Rubicon. I plan to travel / live in the jeep several weeks at a time. Not looking to do extreme, recreational rock crawling and off roading but I want the ability to get to remote locations.
I bought the jeep used and it came with new 33" tires, so I'm obligated to put some miles on them but I keep looking at 35's.
I've added a 2.5 Rubicon express lift and I put a Smittybilt XRC Atlas Front bumper and Smittybilt winch on it.

I am thinking about putting the Smittybilt XRC Atlas rear bumper and tire carrier on next but I am having all kinds of second thoughts about the weight.
I like the rear bumper and tire carrier because I can carry extra water and fuel on the carrier along with a jack and other recovery equipment, antennae, lights etc.
One spec I saw on the bumper says it weights 190 lbs - the couple of reviews I've read/watched simply say it is indeed heavy.

I figure cargo weight has to go somewhere. Water could go inside but fuel definitely needs to go outside either on the bumper or on a roof rack. I am going to start out with a sleeping platform inside the jeep and I'll carry my tent for those times I want to sleep outside. I keep looking at RTT's but I just can't justify that cost yet. But, I'm hesitant to put a roof rack on for carrying cargo because I think that may limit my RTT options in the future. Then there's the question of where to put weight anyway - downlow (inside or on the bumper) or up high? Putting weight up high makes the vehicle top heavy so it seem like inside or the bumper would be preferable. Outside seem better for my use since I don't want to have move a lot of stuff around inside when its time to rollout the sleeping mattress.

On the one-hand, a 190lb bumper / tire rack is just a big guy sitting on the back of a jeep designed to carry four passengers plus gear. Am I overthinking / worrying about the weight of this bumper system? Are there some better options I haven't come across yet?

Thanks for your thoughts.
 

GBGCR4x4

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Shoot, can't speak from experience with a Jeep, BUT I have an Armada, with a Slimline roof rack and a tent. It's very heavy, I also got an OME suspension and changed the tires for bigger ones. It got quite heavy, so I drifted away from getting a front or rear bumper. But that's me, as I do feel a big difference when breaking! I preferred the rack, since it gives me the possibility of a tent as well as carrying cargo boxes on it.
 

loper

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Weight on the rear bumper will take weight off the front (leverage), and may stick out enough to affect your departure angle.
Weight up high, however, might tip you over.
An awful lot of people have rear storage on an awful lot of Jeeps and do OK, I think you would be better off with the bumper mount.
But I hear you, overthinking seems to go with the territory!
 

bgenlvtex

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Weight between the axles is almost always going to be better than weight behind/in front of the axles.
 

94Cruiser

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If your rear axles are full floating, it probably won't hurt to have the weight on the bumper.... better low center of gravity as well....

Also, you're pulling off a bumper to replace a bumper- so there's a little weight break there...
 

jarredBrown

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Weight on the rear bumper will take weight off the front (leverage), and may stick out enough to affect your departure angle.
Weight up high, however, might tip you over.
An awful lot of people have rear storage on an awful lot of Jeeps and do OK, I think you would be better off with the bumper mount.
But I hear you, overthinking seems to go with the territory!
good point to mention




 
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MOAK

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A 190 lb bumper seems a bit heavy. When you upgraded your suspension did you get springs that would upgrade your GVWR? If not, you may want to rethink that. The JKU is an excellent platform, cept for one major thing, very low GVWR. If it were me, and it used to be, as I did the jeep thing for decades, I’d look for the lightest rear dual swing out bumper available, ( aluminum?) get some Old Man Emu “ heavy” springs to compensate for all the weight gain and keep heavy stuff off of the top of your vehicle. Sure, we have stuff up top, dried food, winter clothing, 5lb propane bottle, portable shower and a solar panel, all of which weighs less than about 75lbs. Also, a jeep will lose 3-4 mpg with a loaded roof rack. We were lucky to average 10mpgs. Ask me how I know.. good luck
 

Bob Berryhill

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I have been needing to calculate payload. I need to determine the actual curb weight but this is probably pretty close.
  • GVWR: 5412 lbs
  • Curb Weight: 4314 lbs
  • Payload Capacity (GVWR-Curb Weight): 1098 lbs
Smittybilt says the bumper / carrier actually weights 240 lbs - nearly a quarter of the "stock" payload capacity. I need to rethink that system and cargo planning.
 

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MOAK

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Yea, I’d stay away from smitty bilt. That’s a frigging heavy bumper- to what end? It may look cool, but cool rarely translates to a quality usable product. Cheap steel and even cheaper production results in a lot of very heavy products. When mine was done, a long long time ago, I went with Slee bumpers. Strong, simple, reliable, and , nearly 200 lbs. the front bumper is 90lbs. if I were building it now, I’d give serious consideration to aluminum, or at least something a lot lighter than you are looking at.
 

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@Bob Berryhill you are on the same path that I was on a few years ago. Here are my thoughts from what I learned about the Jeep before I eventually went to a mid-sized truck. However, it should be noted that my gain from going to a different truck was not as significant as I had hoped by the time I water and dustproofed everything.

For my jeep build, I learned that the stock JK tire carrier is good up until about 33", but bigger than that in tire sizes and often the hinges on the rear door will take a beating and ultimately fail (obviously it depends on the rubber weight too as some combos are lighter than others). But as a general rule, if you are going for bigger than 33" tires with the need to haul a jerry can and a few other tools, a rear bumper with a tire carrier is a good bet because that gives you a platform for both the larger tire and a fuel can or two with plenty of strength and durability for off road abuse. You can also get tire racks, water and fuel carriers, etc. and other types of mounts for a rear bumper so there are a lot of options there to make it efficient storage of space.

However, if you are planning on sticking with 33" or smaller longer term, and also planning on any other roof-based accessories like an awning, I would look to a roof rack for storage of kit and just use the stock tire carrier and bumper, since your use case doesn't sound like it will need rear armour and you should already have a rated recovery point out back. A hybrid option would be a reinforced tailgate spring; I seem to recall Rugged Ridge maybe make one (Might have been Ares Offroad though?), which would allow a bigger tire in the stock location without a full bumper replacement. But, the weight of the replacement hinge might not be too far off the weight of a replacement rear bumper, so best to double check. The same is true of racks - some are fairly light and bolt through the hard top into the roll bar. This takes away some of the "top off" functionality but if that doesn't matter, these options are often much lighter than the "Cage" style racks like the Gobi or Kargo Master.

There are advantages and disadvantages of weight in both places, so much so that it's a bit of a wash in my books -- but if you aim to keep the weight as low as possible and stay within GVM, you won't have a problem with stuff stored either up top on a rack or out back on a bumper. Both will impact the way the vehicle drives a little bit, but neither will be a major problem unless it's super overloaded.

Depending on which RTT you get (if you choose to do so), you can have room for both an RTT and cargo up top. On our Jeep had room for a spare tire and a few bags above the driver and passenger, whereas above the rear passenger and cargo area we had room for a Kukenam 3 tent which was plenty big for two adults and two dogs. Some bigger tents like the Smittybilt XL or the iKamper would take much more of the roof real estate though.

As you've identified, a front and rear bumper takes up a huge chunk of payload. That being said I'm a big fan of a bulbar up front, and love the ARB quality and design. But they are heavy, so you might want to consider an aluminum option - as long as you get something with a full hoop, that is from a reputable vendor, you should find that you can get a solid "one deer" bumper that will allow you to experience an animal strike and still drive home. Without one, an animal strike likely means calling a tow truck. If you do want to go with a rear bumper, as I said above, that would be mainly for cargo carrying, and in that respect I would go for the lightest option which again might be aluminum though I would also look for some tubular options since you likely won't need the rear bumper as armour. Quadratec make some aluminum bumpers for the JK and I think a company called GenRight also made them but it's been a few years since I've had to look.
 

Bob Berryhill

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Thank you for the extensive input. Good news is I don't have to do anything right away - just need to keep reminding myself that :).
Looking forward to getting to some of the expos this year so I can put eyes and hands on some of these options and see what others have done. On-line shopping is great but its hard to see how these options come together.

My takeaways are:
1) Rear bumper provides a good place for storage but there are much lighter options than the 190-240 lb bumper I've been looking at. Storage is more important, in my case, than heavy duty armor. The LoD destoyer is a pretty good looking option and I'm thinking that basket over the spare tire might not be so bad either. Integrated latch system is becoming a higher priority as well.
2) A roof rack and RTT are probably in the future with the intention of using some of that rack space for storage. I'd like to keep the freedom tops uncovered but I don't mind "permanent" mounts that require the hard top to stay on. The Rhino 72x56 rack looks like the right approach.
3) The weight has to go somewhere. Minimizing the weight is the first step. Keeping the weight lower is better but there's a trade-off in keeping it centered on the chassis rather than all piled up on the bumper.

I think I'll start a "build thread" soon to get your expertise.
 
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smritte

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The biggest challenge your going to face with things bolted on your vehicle are wash board roads. Hills, if you choose to go beyond simple (hitting and dragging).

First, just understand you will be changing springs. An average 33" tire and rim, will weigh in close to 80# and some will be more. My 37" Mud grapplers on a Walker Evens rim were over 100#

Picture going down a wash board road. Your tire is vibrating front to back. Being as its mounted externally, you add in leverage. Sheet metal mounted tire carriers sooner or later will stress crack. Factory mounted tires on sheet metal are not designed for what we do and are rated for stock tires. Bumper mounted carriers have to over come their own problems. Same weight plus the metal mounting the tire. Add in the leverage from how high the tire is above the bumper and that it is how much stress is on the lower mount. If fuel/water is mounted there also, add in that.

I do most of my own fab work. These are things that need to be considered on a build. My current rear bumper has the tire on one mount and fuel/water cans on another. This is how I split up the weight. Both mounts are high enough to not have an issue with dragging no matter the incline of the hill.

Total weight in the back is 70# fuel (max), 70# tire/rim, 160# bumper and carriers. Around 300# with 160# suspended above (including the risers and mounting). The bumper itself, with no mounting is a bit over 100#.
My several Jeeps had something similar with everything on one swing out. The weight was pretty close to what's posted. The jeeps were also built to drive hard core trails. It's not the hard core trails that's the issue, its the wash board roads.

Over the last several decades, I have participated in diffrent off-road events. These ranged from easy trail rides to rock crawl. The milder events is where I have picked up several items I found on the trail. Quite a number were spare tires and fuel cans with the mounting hardware attached. Yep, you guessed it, washboard roads.

What I'm saying here is plan out your build properly. Its going to be an on going project with a bunch of custom thrown in. Its ok to have springs that are too heavy in anticipation of your bumpers (If not you end up buying springs twice).
Try to keep the bulk of the weight as low as possible. I see some people put their spare and fuel on the roof. Personally, I don't like the way the vehicle feels on corners and side hills. The people I see doing that are pretty much driving flat dirt or copying what they see in magazines and think its a one size fits all. Fortunately Jeep tends to overkill its sway bars, that's a big help with roof mounted RTT's.

Because of where I drive, my light gear goes on my roof and my heavy items are on my bumper. My springs/shocks match my load. My rear bumper and suspension see the most stress. I check these often. This includes marking bolts/nuts with a paint pen to see if something loosened.

OH, welcome to the crazy we call off road.
 
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