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  1. Anti-Sway Bars
  2. Roadmaster
  3. Anti-Sway Bar
  4. Rear
  5. 1-1/2 Inch Diameter
  6. Mounting Hardware Included
THIS ITEM IS NOT A FIT FOR
2025 Mini Cooper
Roadmaster

Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter

Part Number: RM-1139-198
In Stock
$665.00
Retail:$741.02
You Save: $76.02
Anti-Sway Bars
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2025 Mini Cooper

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Minimize sway and driver fatigue by improving the stability and driveability of your vehicle. The bar on this sturdy, effective anti-sway system mounts to the rear axle and to the frame to balance weight transfer and reduce body roll. 1-800-940-8924 to order Roadmaster anti-sway bars part number RM-1139-198 or order online at etrailer.com. Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster Rear Anti-Sway Bar - 1-1/2" Diameter. Anti-Sway Bars reviews from real customers.
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Roadmaster Anti-Sway Bars - RM-1139-198

Highlights

  • Custom Fit for Your Vehicle: Tuned to your suspension for better control and stability.
  • Reduces Sway: 1-1/2" 4140 chromoly steel bar cuts side-to-side roll for steadier control.
  • Handles Crosswinds: Keeps the vehicle level through gusts, passing traffic, and shifting loads.
  • Less Driver Fatigue: Reduces steering corrections so long drives feel smoother and easier.
  • Levels the Ride: Balances weight transfer over rough or uneven roads for predictable handling.
  • Uses Existing Connections: Mounts to rear axle and frame with included hardware—no drilling required.
Made in USA

Features to know about

More Control on the Road: Rear Bar Reduces Roll and Sway

There’s no mistaking the feel of a rig that rocks and leans through corners or when a semi blasts past. The 1-1/2" diameter Roadmaster Rear Anti-Sway Bar ties the rear axle to the chassis to balance weight transfer and tame that side-to-side movement. The result is a flatter, more composed ride that stays steady through turns, gusty wind, and rough stretches of highway.

Roadmaster Rear Anti-Sway Bar installed on vehicle rear axle showing mounting points and bar placement for improved stability

Less Fatigue on Long Drives: Stable, Predictable Handling

Long hauls don’t have to mean constant steering corrections. By cutting out sway and body roll, this bar helps the vehicle track straight and level, even with crosswinds or shifting weight in back. It means less tension in your shoulders and a much more relaxed drive from start to finish.

Built for Strength: 4140 Chromoly Steel Construction

This isn’t a standard steel tube. The bar is built from thick 4140 chromoly steel—tougher and harder than typical 1020 steel—and that larger 1-1/2" diameter adds torsional stiffness. It resists flex and twist almost 30% better than average bars, giving you a setup that holds its shape and performance mile after mile.

Durable Support: Polyurethane Bushings That Last

Every pivot point matters, and these polyurethane bushings keep things tight without being harsh. They resist oil, gasoline, and ozone, so they don’t soften or wear out like rubber. That means a more consistent feel in the suspension and long-term reliability no matter how far the road takes you.

Close-up of Roadmaster anti-sway bar polyurethane bushings showing durable construction and mounting configuration

Straightforward Install: Heavy-Gauge Hardware, No Drilling Required

This bar bolts directly to the axle and frame with the included heavy-gauge mounting hardware and bushing lubricant. No drilling, no complicated mods—just a solid, bolt-on improvement that works right alongside existing suspension gear for a noticeable upgrade in stability and control.

Specs

Dimensions

  • Bar diameter: 1-1/2"

Warranty

  • Limited Lifetime Warranty

1139-198 Road Master Anti-Sway Bar - Rear

Installation Details RM-1139-198 Installation instructions

This Product Fits The Following Vehicles




Customer Satisfaction Score:

Ratings & Reviews

4.8

2516 reviews
5 Stars
(2154)
4 Stars
(248)
3 Stars
(48)
2 Stars
(22)
1 Star
(44)
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Minimize sway and driver fatigue by improving the stability and driveability of your vehicle. The bar on this sturdy, effective anti-sway system mounts to the rear axle and to the frame to balance weight transfer and reduce body roll.

by:

1 of the best purchased I've made for my Fleetwood Discovery. All wandering is now gone. Took an afternoon to install (I'm a retired mechanic) and am very pleased with the outcome. I also purchased an Steering Stabilizer Shock a year before and I improved wandering maybe %25. Both purchases arrived (in Alaska) promptly and in good condition. I Will purchase from eTrailer.com again when needed.



by:

I love this sway bar, and love the service and overall experience with etrailer. My F350 came with factory sway bars front and rear, and I'd replaced the rear bar several years ago, and was impressed with the difference it made. So, more recently I ordered the front bar to replace the smaller factory unit, and it again made a wonderful change for the better. Our Bigfoot truck camper is tall and heavy, but our rig handles wonderfully and has essentially no sway or rock in traffic or on bumpy roads. I highly recommend this sway bar.



by:

I have a hard side slide in camper in the back of my pickup. This is the first time I installed an Anti-Sway Bar of any kind. It took me about 6 hours to install. But it works, and it works really well. I'm glad I took the time to install it.



by:

Easy installation ,done by myself laying on my back in the driveway only took about 1 1/2 hours to do. I have a lift but didn't use it and I think it was easier on the ground for just one person. Sway bar made a big difference in the drivability of my 2003 E350 pleasure way class B
I'll upgrade the front factory bar to the HD Roadmaster bar soon
If you have issues with the handling of your Ford pleasure way start with this sway bar



by:

After a year of usage, I couldn't be happier with the Roadmaster front and rear anti-sway bar kits. The rear kit for my W22 chassy, the mounting hardward would not fit properly. I call Roadmaster directly and they custom built the mounts, painted, and shipped within days.



by:

Super quality product build. However it is made for ford transit dually. I have single rear tires. Worked with road master rep to select the correct sway bar for my van.. RM82EQ



by:

I Installed the bar in my Ram promaster HR 2500 and it’s an incredible difference on twisty mountain roads. I highly recommend it.



by:

After waiting 3 weeks the swaybar kit was drop-shipped from the factory. Received and discovered the bushing inserts were the wrong size (too small) for the bolts that were sent. Contacted Roadmaster support and provided them a photo and invoice as requested. The replacement inserts were approved and shipped out. I got metric bolts to go with the inserts I received. I will save the replacements for additional replacements.
The install was fairly straight forward.
Haven't had a chance to tow the 5th-wheel yet.



by:

a quick fix it to install sway bars front and rear.
I did this and just came home from 2400 mile trip.
installed rear only before we left, then at our destination installed front.
the drive back it handles wayyy better and it sits level now.
""your results may very-use at your own risk. ""
from etrailer.com
rear = RoadMaster 1259-109.
front = RoadMaster RM-1259-105 with RM-590063-00 bracket kit.
i'm sure over time they will flex and stress and start to lien again.
But for now it looks much happier. ( and level )
and i'm very happier with performance and drivability
Seems the big bars help distribute the load to both sides,
you can drive it with one hand now.
and when a truck passes, it's very manageable.
( this could be part the tires on it )
these can be installed in about 6 hours pretty easy.
The hardest thing is drilling the 8 holes in frame. ( 4 front 4 rear. )
We had to shift 2 brake lines over via and small bracket and covers lines with old fuel like to act as wear buffer.



by:

The anti sway bar is a big improvement when the truck bed camper is on. The installation took a bit longer than expected because the frame brackets don’t fit around an aftermarket B&W gooseneck hitch. I had to fabricate new top brackets and drill out the bottom brackets to widen the bolt pattern. Keep this in mind if you have a gooseneck hitch.



by:

Received the product in a timely manner. The shipping company used I’d give a no star rating. I received the anti-sway bar bare out of a box or wrapper with the installation part box and a cut out piece of cardboard with the shipping label on it taped to the bare bar with about five yards of packing tape. The bar was scuffed, scratched and chipped with the RoadMaster label destroyed. I realize it’s going to be installed under the front of my motorhome but as much as it costed I would like to be the one to scratch and scuff it. If I was a company installing this on a customers vehicle I’d return it. I do not believe it was shipped from etrailer in this condition.



by:

Great buying experience with ETrailer. Fast shipping and quality constructed part. Noticeable difference in controlling body sway. Very pleased with the bar and highly recommend Etrailer.



by:

After about a year with both the Roadmaster Rear Anti-Sway Bar and the TorkLift StableLoad Upper Overload Spring Upgrade on our truck camper setup, my experience has been mixed.

With the StableLoads, some of the mounting screws eventually fell out. I contacted etrailer expecting the issue to be handled under warranty, but instead of taking care of the replacement directly, I was referred to the manufacturer. Considering the age of the product and that it was purchased through etrailer, I was disappointed with how the warranty issue was handled.

As for the Roadmaster 1-1/2" rear anti-sway bar, it is a very solid and well-built product, but in our particular application I honestly haven't noticed a major difference in body roll while taking turns with the camper loaded. I have driven the truck both with and without it, and the improvement was much less noticeable than I expected.

Neither product is necessarily bad, but based on our experience, the improvement in handling hasn't been significant enough for me to strongly recommend them given the cost.



by:

2025 Sprinter 2500 low roof WITH factory sway bar. Added this bar to control the terrible handling at the rear of these vans and it absolutely takes care of that. Be aware that you 100% need the retro-fit kit for this bar to be installed as the factory sway bar end links will NOT work. The retrofit kit that you need is the RM-590064-00.



by:

RM-1109-121 Rear Sway bar for 85 Chevyvan G30 RV. Install was pretty straightforward. I would mount the brackets to the frame first and then the sway bar to the axle. It’s easier to drill the holes without the sway bar getting in the way.
Before I replaced the shocks and upgraded the from sway bar and added the rear sway bar my G30 Chevyvan Winnebago was a wallow wagon. It took 110% focus to drive. Now it drives like a regular vehicle. Smooth. No leaning over when cornering. It’s night and day.



by:

Excellent high quality product made a big difference in handling with heavy Artic Fox camper
Give poor rating regarding installation instructions



by:

Great instructions and nice, high quality fasteners.
Fitment was great and only minor adjustments to my Air lift air bags was needed.
I have a 2013 Ram 3500 Dually with:
-Torklift 30K hitch
-5” Exhaust
-Air lift 7500XL air bags.
The lower brackets for the air bags needed to be moved slightly and I had to cut the excess bolt off on the passenger side.



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by:

This was an excellent piece. Made a huge difference in the drivability and handling. It was easy to install took about 45 minutes.
I highly recommend this product, worth every penny.



by:

Great products, amazing support staff. Sarah H. was very professional and helpful. I would give all my business to etrailer due to their product variety and knowledgeable staff. Thank you!



by:

Replaced front and rear on a 2017 25’ Minnie Winnie. Difference was night and day. Over 10k trip from texas to alaska was a lot more pleasant drive!



by:

I really liked that this sway bar was fitted for my RV where I did not have to use the u-bolts and was able to bolt into the existing framework. I could tell somewhat the difference in driving with this unit but wanted to see the full extent with the front sway bar, which I am still waiting on to be delivered. Just after I installed this rear sway bar we went on a trip up to Colorado, but got snowed in and had to head back in a couple of day through icy conditions. This sway bar really made all the difference in the driving especially around semi-trucks passing either direction. Thanks.



by:

I have a 1994 Airstream B-190 motorhome on a Ford E-350. I saw these sway bars in the catalog for years. I put the back one on 1st it made a world of difference, so I put the front on as well. Should have done this years ago. Don't let the pictures fool you these bars are about as big around as your wrist and very heavy duty. Took a lot of the sway out the top-heavy conservation van. I recommend this sway bar and wish I would have put it on some of my other regular Ford Econoline vans a long time ago

Mike D. profile picture

Mike D.

6/1/2023

LOVE them!!! AIRSTREAM should have put them on this unit as standard OEM factory. My B-190 is a 1994 has 53K and now I find I use it a lot more than I did before because it drives so much better with these heavy-duty sway bars! I combine these with airbags in the front and air shocks in the back and let me tell you it rides as good as my Caddy down the road. I recommend these sway bars to anyone that has a full size Van and wants a superior ride and drive ability upgrade for not a lot of money.



by:

RM-1139-198 is of high quality. Haven’t tested but have installed. Easy install, I was able to reuse the factory bolt holes on anti-sway bar and frame. Which made it fast and easy. Huge difference in size of RM to factory bars. Only issue I had was I ordered kit number RM-1139-198 to fit my 2018 Ford E-350 and this kit was garrantied to fit. But nothing on this product said ONLY if your E-350 or E-450 has auto drop down tire chains, oops I learned this after I received and started install. Part needed is RM-1139-117 which has 11 inch center to center bolt holes on links instead of the shorter 9 inch. The 9” links are just too short to work. I had to order the longer end links and yes they weren’t free. If you watch the install video on either kit number the tech points this out and with the longer links mine bolted up exactly as the video stated. After testing for awhile I’ll review the product again. This is the only improvement I’ve made so far.

Leonard profile picture

Leonard

6/30/2022

Been a year now and I will say “it’s the best and first thing you should do to improve the drivability and suspension”. If you motorhome came with stock antisway bars that are small in diameter than the RM then this will make a very big difference in handling on curves and crosswinds, semi trucks.


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See what our Experts say about this Roadmaster Anti-Sway Bars

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    We do have the anti-sway bars, steering stabilizer, and helper springs that will giver your Class C motorhome on a 1997 Ford E-350 chassis a much better ride. To best improve your ride you will want the rear anti-sway bar, followed by the front anti-sway bar, and steering stabilizer. These will give you the greatest improvements with the most comfort to your motorhome. I confirmed with the manufacturer the following fits, and the rear anti-sway bars are going to depend on if you have automatic...
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Do you have a question about this Anti-Sway Bar?


Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video Edited:
Joshua S
Employee John S
Video Edited:
John S
Employee Wilson B
Updated by:
Wilson B
Employee Isabelle B
Updated by:
Isabelle B
Employee Sabrina W
Updated by:
Sabrina W
Employee Mike S
Written by:
Mike S
Employee Ryan G
Test Fit:
Ryan G

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