Rear bumper question

coloradomtn

coloradomtn

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Hi, I’m looking to put a 4 bike rack on the back of my ’03 TJ. The combined weight of the rack and the bikes will be approx 170lbs (rack is 70lbs and the bikes are around 100lbs).

My understanding is that my TJ has a 2,000lb hitch rating which translates to a tongue weight rating of approximately 200lbs. Given the weight of the bikes will be sitting out from the Jeep I’m concerned that I’ll be over the tongue rating and should get a Draw-Tite hitch that is rated for 300lb or 400lbs of tongue weight.

I’d much prefer to get a new rear bumper with an integrated hitch like a Hard Rock or LoD versus the Draw-Tite. Do you think the Hard Rock or LoD would be able to support the load? I’ve spoken to both Hard Rock and LoD and they said their bumper ratings matched Jeeps but could not given me a class rating for the hitch.

I’ve got a 2” lift (Rancho shocks & BDS springs), run 31” tires and have a Warn 8000 winch. My front bumper is being upgraded to either the Hard Rock Patriot or LoD Signature so I can tow the Jeep behind an RV. I’ll check how balanced the TJ is after the rack and bikes are installed and if needed add rear airbags.
 
Something to keep in mind hanging extra weight off the back of the jeep, I have a rampage rear recovery bumper with a swing-out spare tire carrier that I added a titan 12 gallon fuel tank onto, sitting on 3.5" lift with 33x12.5-15 tires. Now you are running 31's, but I notice with the spare tire and when my 12 gallon fuel tank is full there is a different (floating) feel to the handling with the weight of my spare and the full tank with the extra 12 gallons of fuel (70#'s) vs when I redistribute the fuel into my main tank and my titan fuel tank hanging off the back of the jeep is empty. My bumper handles the extra weight off road fine but needed some minor modification to keep everything in place. Also, I'm not recommending the rampage bumper just adding that the weight hanging farther back off the bumper seems to affect the handling of my jeep.
 
coloradomtn said:
We're considering the rear air bags by Air Lift. If we do end up installing them I'll post before and after pics.
Click to expand...
If you dig around my build thread, I discuss my AirLift installation. I disagree with AL's recommendations for fitting them onto a TJ, especially if you have lift springs and bump stop extensions. Basically, you want the largest deflated bag that will fit between the axle pad and the bump stop jounce. Don't cut or remove the jounces, as they tell you to to do.
 
I installed those on my truck. The hardest part was getting them small enough to fit inside the springs. They work great and I have not had any issues so far.
 
1515art said:
Something to keep in mind hanging extra weight off the back of the jeep, I have a rampage rear recovery bumper with a swing-out spare tire carrier that I added a titan 12 gallon fuel tank onto, sitting on 3.5" lift with 33x12.5-15 tires. Now you are running 31's, but I notice with the spare tire and when my 12 gallon fuel tank is full there is a different (floating) feel to the handling with the weight of my spare and the full tank with the extra 12 gallons of fuel (70#'s) vs when I redistribute the fuel into my main tank and my titan fuel tank hanging off the back of the jeep is empty. My bumper handles the extra weight off road fine but needed some minor modification to keep everything in place. Also, I'm not recommending the rampage bumper just adding that the weight hanging farther back off the bumper seems to affect the handling of my jeep.
Click to expand...

We're hoping the rear airbags will help to reduce the rear end floating feeling. Most of the times when the bikes are on the rack the Jeep will be towed behind a class a diesel pusher so we want to make sure a rear bumper bar with an integrated hitch is capable of carrying the extra tongue load and is stable to tow. If we're taking the Jeep offroad we'd remove the bikes and the rack. With rear airbags, we'd be able to reduce the amount of air in the bags and level the Jeep for both scenarios (offroad and towing).
 
coloradomtn said:
We're hoping the rear airbags will help to reduce the rear end floating feeling. Most of the times when the bikes are on the rack the Jeep will be towed behind a class a diesel pusher so we want to make sure a rear bumper bar with an integrated hitch is capable of carrying the extra tongue load and is stable to tow. If we're taking the Jeep offroad we'd remove the bikes and the rack. With rear airbags, we'd be able to reduce the amount of air in the bags and level the Jeep for both scenarios (offroad and towing).
Click to expand...
The biggest issue with adding weight behind the rear axle is the teeter totter effect. The rear will squat and the front will lift. I had to deal with this when I added a heavy bumper and tire carrier. I've always needed to use a "taller" spring in the rear to achieve the normal ride height I wanted. And the front always rode a bit taller than advertised. Then I added the bags for those times I carried additional heavier cargo.

All of this falls into the discussion of sprung weights, spring rates, and actual ride heights. It's an interesting topic.

As far as finding a bumper, very few manufacturers will rate their bumpers for towing. The costs and liability are too high. But making a strong bumper that can safely tow or carry gear isn't rocket science.

What you need, no matter what, are frame tie-in brackets. These will connect the bumper to the frame and significantly increase the capacity of the bumper. Any bumper that will carry weight or pull any load must be directly tied to the frame.
 
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jjvw said:
The biggest issue with adding weight behind the rear axle is the teeter totter effect. The rear will squat and the front will lift. I had to deal with this when I added a heavy bumper and tire carrier. I've always needed to use a "taller" spring in the rear to achieve the normal ride height I wanted. And the front always rode a bit taller than advertised. Then I added the bags for those times I carried additional heavier cargo.

All of this falls into the discussion of sprung weights, spring rates, and actual ride heights. It's an interesting topic.

As far as finding a bumper, very few manufacturers will rate their bumpers for towing. The costs and liability are too high. But making a strong bumper that can safely tow or carry gear isn't rocket science.

What you need, no matter what, are frame tie-in brackets. These will connect the bumper to the frame and significantly increase the capacity of the bumper. Any bumper that will carry weight or pull any load must be directly tied to the frame.
Click to expand...

Good to know someone has installed the rear airbags. I'll be sure to read your build thread.

The Rock Hard 4X4 Patriot rear bumper has a frame tie-in bracket kit. Given your comment, we'd go with this bumper over the LoD bumper which doesn't. We spoke to Rock Hard and they said the bumper was rated to match the stock Jeep ratings but my guess is that is a safe answer for liability reasons. Their bumper is designed to support heavy spares, tank mounts, cargo baskets so we're hoping it will work with the rack & bikes.
 
Go for the US made http://www.thedirtworx.com/product-page/rear-bumper rear bumper with its integrated 2" receiver hitch and you'll be fine. I've run that bumper on two different Jeeps and it's a beefy well made bumper.

If that heavy of a bike load will be commonly carried and it drops your rear end more than you like, which it may not depending on your rear springs, you can always go with heavier rear spring rate.
 
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To @coloradomtn:

In view of the weight you intend to carry, and for your particular needs, my recommendation would be the made-in-U.S.A. Rock Hard 4x4 rear bumper over the offerings by LOD, Dirtworx and most other vendors. Frame tie-ins may not be necessary for a bumper that only carries the weight of a spare tire but are strongly advised for the cantilevered 100 lb. aggregate weight of 4 bicycles (or jerry cans, jacks, etc.) or if you decide in the future to tow a trailer. Rock Hard 4x4 offers frame tie-ins. Also, the latch for the swing away arm on the Rock Hard 4x4 rear bumper is superior to the competition.

Since you are already planning on a Rock Hard 4x4 front bumper you might as well get a matching product for the rear.

Photos of my Rock Hard 4x4 bumpers (the previous owner gets the credit for choosing them; I added the Rock Hard 4x4 jerry can mounts):

Jerry Cans 2.jpg



After first day in the dirt.jpg


Rear Bumper and Tire Carrier.JPG


Front Bumper.JPG
 
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Frame tie-ins are always recommended when towing or carrying heavy loads on the hitch no matter what brand bumper is installed.
 
Jerry Bransford said:
Go for the US made http://www.thedirtworx.com/product-page/rear-bumper rear bumper with its integrated 2" receiver hitch and you'll be fine. I've run that bumper on two different Jeeps and it's a beefy well made bumper.

If that heavy of a bike load will be commonly carried and it drops your rear end more than you like, which it may not depending on your rear springs, you can always go with heavier rear spring rate.
Click to expand...
i also have the dirt works rear bumper with 2 5 gal jerry cans spare tire mounted between tail gate and tire also a highlift jack on top of the loop for the jerry cans behind the spare it also swings out I modified the latch it had to a brake away latch instead of the T bolt style that it came with work and function great
 
Mr. Bills said:
To @coloradomtn:

In view of the weight you intend to carry, and for your particular needs, my recommendation would be the made-in-U.S.A. Rock Hard 4x4 rear bumper over the offerings by LOD, Dirtworx and most other vendors. Frame tie-ins may not be necessary for a bumper that only carries the weight of a spare tire but are strongly advised for the cantilevered 100 lb. aggregate weight of 4 bicycles (or jerry cans, jacks, etc.) or if you decide in the future to tow a trailer. Rock Hard 4x4 offers frame tie-ins. Also, the latch for the swing away arm on the Rock Hard 4x4 rear bumper is superior to the competition.

Since you are already planning on a Rock Hard 4x4 front bumper you might as well get a matching product for the rear.

Photos of my Rock Hard 4x4 bumpers (the previous owner gets the credit for choosing them; I added the Rock Hard 4x4 jerry can mounts):

View attachment 45237


View attachment 45241
Click to expand...
 
mr. bills where are you located im here in n/w red bluff baker and 36 give me a call if your anywhere close 949-8165
 
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