Radius Arm vs. Control Arm Setup
05-23-2006, 06:37 PM
#1
Registered User
Thread Starter
Join Date: Nov 2005
Location: Fayetteville, NC
Posts: 145
Likes: 0
Received 0 Likes
on
0 Posts
Radius Arm vs. Control Arm Setup
Ok.... I'm looking for some technical advice on the subject. 
What are the advantages/disadvantages of a long-arm radius kit vs. a 4 link control arm setup (which is what our truck has, stock). I'm not talking about a longer, lower control arm, but the full radius arm set-up. (example: DTprofab ) I want to get longer control arms, but now I'm thinking that maybe the radius arms would be money better spent. I'm not worried about losing the stock set-up either. I just want the best all-around offroad/onroad truck I can build.
-I know that caster/camber angles are easier and better with a radius arm, but what does that translate into? (better tire wear, no deathwobble, etc.)
-Are the advantages noticeable on a mostly street-driven truck, or is this an option only needed for hard-core offroading?
-What are other advantages of switching to this kind of set-up?
-How hard would the installation of a long-arm kit be?
I know that Cowhand has this done on his truck. Any input from those who know would be much appreciated. And please, get as technical as you can. I love learning all this stuff!!
The plan is Don Thuren Trackbar, Steering Arm kit and either Control Arms or Radius Arm for my truck in August. Hoping to make the truck steer like a sports car, lol.
Cheers, Dave
What are the advantages/disadvantages of a long-arm radius kit vs. a 4 link control arm setup (which is what our truck has, stock). I'm not talking about a longer, lower control arm, but the full radius arm set-up. (example: DTprofab ) I want to get longer control arms, but now I'm thinking that maybe the radius arms would be money better spent. I'm not worried about losing the stock set-up either. I just want the best all-around offroad/onroad truck I can build.
-I know that caster/camber angles are easier and better with a radius arm, but what does that translate into? (better tire wear, no deathwobble, etc.)
-Are the advantages noticeable on a mostly street-driven truck, or is this an option only needed for hard-core offroading?
-What are other advantages of switching to this kind of set-up?
-How hard would the installation of a long-arm kit be?
I know that Cowhand has this done on his truck. Any input from those who know would be much appreciated. And please, get as technical as you can. I love learning all this stuff!!
The plan is Don Thuren Trackbar, Steering Arm kit and either Control Arms or Radius Arm for my truck in August. Hoping to make the truck steer like a sports car, lol.
Cheers, Dave
05-26-2006, 12:31 AM
#2
Registered User
Join Date: May 2003
Location: The 951-Flatbill center of the universe
Posts: 1,515
Likes: 0
Received 0 Likes
on
0 Posts
You covered most of it...
More predictable caster angles, better tire wear and no death wobble. My truck is a daily driver, but it works great for hardcore off road too.
Less moving parts to wear out, so that's less you have to chase if there's a problem. Front end feels tight like it should.
Don's set up is a little different than mine...I know pretty much what he's gonna do but I don't know what the frame brackets will look like, we didn't get that far. Don's fine tuning the design and it should work like everything else Don does
More predictable caster angles, better tire wear and no death wobble. My truck is a daily driver, but it works great for hardcore off road too.
Less moving parts to wear out, so that's less you have to chase if there's a problem. Front end feels tight like it should.
Don's set up is a little different than mine...I know pretty much what he's gonna do but I don't know what the frame brackets will look like, we didn't get that far. Don's fine tuning the design and it should work like everything else Don does
05-26-2006, 12:37 PM
#3
Registered User
Join Date: Oct 2004
Location: Roswell, GA
Posts: 94
Likes: 0
Received 0 Likes
on
0 Posts
If you going to drive on the street with a lot of lift then go with radius arms or also what I call long arms. The geometry works better and no death wobble. When you do a suspension lift on stock arms (short arms) they start to get to vertical vs the stock horizontal position. That helps to cause death wobble. And of course all the reasons Cowhand said to.
05-26-2006, 02:19 PM
#4
Registered User
Join Date: Apr 2005
Location: Denver, CO
Posts: 1,162
Likes: 0
Received 0 Likes
on
0 Posts
I dunno if you guys have ever experience REAL death wobble, but just putting a lift on, even with bad geometry, will no cause it. Only loose and sloppy front end components will do that, but a lift magnifies it. I know this from experience with my Jeep (same basic suspension design). Real death wobble can cause you to lose complete control of the vehicle. Happened to me a couple weeks ago with the Jeep. I knew I shouldn't have been driving it on the street due to a worn/busted trackbar, but I did anyway and I almost lost it when the death wobble started and literally threw my hands from the wheel for a second. Good thing I was on a straight road.
Either way, long arms will always ride better on the street than short arms, due to less arc in the travel of the arm.
Either way, long arms will always ride better on the street than short arms, due to less arc in the travel of the arm.
05-26-2006, 02:39 PM
#5
Registered User
Join Date: May 2003
Location: The 951-Flatbill center of the universe
Posts: 1,515
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 4x4not
I dunno if you guys have ever experience REAL death wobble, but just putting a lift on, even with bad geometry, will no cause it.
The DW subject has pretty much been
What I find especially amusing is the increasing frequency of DW in 3rd gen trucks with the AAM axle and the "bulletproof" 3rd gen track bar.
Looks like maybe rubber wasn't such a good idea after all.....
05-26-2006, 06:45 PM
#6
Registered User
Join Date: Oct 2004
Location: Roswell, GA
Posts: 94
Likes: 0
Received 0 Likes
on
0 Posts
[QUOTE=4x4not]I dunno if you guys have ever experience REAL death wobble, but just putting a lift on, even with bad geometry, will no cause it. QUOTE]
Not trying to start an agument but yes it will. New ball joints, new bushings, correct alignment and a lift on short arms, guess what, Death Wobble. Installed long arms, death wobble gone. Ask me how I know and if I know what real death wobble is. Yes there is a lot more to DW than control arms but any one single part of that can cause it. I've seen brand new rigs get it after to much lift on short arms. I'm on my second built Jeep and this one has only had it from a loose track bar bolt and it does have long arms also. I agree with you, but you can also get it form just a lift and bad geometry. You know what the best part is, people actually think a steering stabalizer fixes DW.
Not trying to start an agument but yes it will. New ball joints, new bushings, correct alignment and a lift on short arms, guess what, Death Wobble. Installed long arms, death wobble gone. Ask me how I know and if I know what real death wobble is. Yes there is a lot more to DW than control arms but any one single part of that can cause it. I've seen brand new rigs get it after to much lift on short arms. I'm on my second built Jeep and this one has only had it from a loose track bar bolt and it does have long arms also. I agree with you, but you can also get it form just a lift and bad geometry. You know what the best part is, people actually think a steering stabalizer fixes DW.
Thread
Thread Starter
Forum
Replies
Last Post
Patrick Campbell
3rd Generation Ram - Non Drivetrain - All Years
21
09-15-2003 09:00 PM