Mid arm setups....

[TOZOVR]

Pro's? Cons?

Discuss....

[dennisuello]

i want to know as well.

pro - better clearance than long arm,
better ride that short arm.

[Safari Ary]

RJ, did you really just ask this question??:rolleyes: There's this nifty function called a search button. USE IT! This debate has gone on at least 3 times in the past year lasting weeks. Oh that's right, you're not a naxja member, you can't search the old threads. Here's a hint.....JOIN! :D

Ary

P.S. I don't know how many people besides goatman are running "mid-arm" setups, but he can't seem to say enough good things about his.

[offroadman83]

vintagespeed just set up one if I am not mistaken:dunno:

[vintagespeed]

Originally posted by offroadman83
vintagespeed just set up one if I am not mistaken:dunno:
I've seen long arms on the trail and I didn't like the binding and weird problems that the 'radius' arm setup had. Alot of long-arm guys are now running 3 arms vs. the standard 4 proving there was an error in it's design. I like the mid-arm because I get better control arm angles than with drop brackets, less underframe clutter than the drop brackets, and as much flex as I'll be able to use.

[RCP Phx]

When are you going to show us some pics?Id like to see what you came up with,especially the upper link!

[vintagespeed]

Ok, I haven't really organized pics from the buildup cause I'm not really finished yet. Still building steering & misc. stuff like brakes & whatknot. But here's some shots of the build & testing.

Control arm angles & mount profile:

http://www.rockxj.com/images/3link/angles.jpg

I mounted the arms right behind the curve area on the front frame section, still in the thick part of the unibody.

Upper & Lower passenger side mounts:

http://www.rockxj.com/images/3link/both.jpg

(All 3 arms are fixed length with the upper mount having a stock LCA slider & shims for caster adjustment)

Axle mounts (these are now fully boxed in):

http://www.rockxj.com/images/3link/newmounts.jpg

Axle sitting on the ground, note pinion yoke angle and that the d-shaft is not connect and would not be binding even at this massive amount of droop:

http://www.rockxj.com/images/3link/d44_in.jpg

Axle bracket clearance + 13" at the diff w/ZERO psi in 38.5" tires:

http://www.rockxj.com/images/3link/13_inches.jpg

Angles at ride height (during testing):

http://www.rockxj.com/images/3link/rideheight.jpg

And what it looks like today (essentially):

http://www.rockxj.com/images/3link/imag0031.jpg

So there you have it. I would do it exactly the same again, except I raise the TB up above the axle to make clearance for the ram-assist............instead of having to cut off that bitchin' mount.

:D

[JJ13]

looks great...bout maxed out your clearance on the garage it looks like =)

how did you attach the lower mounts to the frame? From the angle I couldn't see if they were just welded. I thought about doing it that way, but was afraid of the integrity of the weld there without the mount wrapping around the sides of the "frame" (for lack of a better term).

[vintagespeed]

Yes, they're welded to the 'frame', I made them longer than the stock LCA mounts and wider to try and get as much weld surface as possible. The unibody actually takes a weld really nice in the thick areas, and I doubt they'll go anywhere.

[BrettM]

so how long are your arms now? typical lifted XJ arms are in the 16-17 inch range, longarms are typically in the 32-36 inch range, so how long are yours?

[KarmirXJ]

man that is some sweet work vintage!

im looking forward to seeing some completed flex shots of that beast!:D

[Goatman]

Yeah, I like mid-arms, or just longer short arms. The issue to me is the angle of the arms, not the length, so the mounting position is the real issue. The compromise, or balance, is between arm angle, arm length, and ground clearance. I have a thing about ground clearance......basically, I won't do any mod that decreases ground clearance. By the time you set up a long arm to not significantly decrease ground clearance, you have increased the angles and removed some of the benefit of the long arms. If you draw out a couple of scenarios on the garage floor in chalk, drawing the arm positions from stuff to full droop, with the axle movement in an arc, it's very dramatic to see what setup will produce the best combination of arm angles and ground clearance.

With a mid-arm (sort of, longer short arm really), you can position the arms for good angles, and keep the mounts both forward and high enough for good ground clearance. The only negative I see to this is that you have to make everything yourself. So, if you aren't able to design and fabricate yourself, you may be better off with drop brackets or a long arm kit (ouch!). The biggest problem with long arm kits is that the LCA frame mounts are below the frame, and way back.......talk about killing break over angle. :eek: Some of the guys who have made their own long arms have moved the mounts higher up, inside the frame rails, which is much better. Drop brackets work very well, but you have to live with the 4" lower frame mount. That can be a problem, but not nearly as bad as long arm mounts under the frame rails further back.

I think the focus should be on ground clearance because, in the big rocks, getting hung up stops you more often than a lack of traction.

Here's a link to pics of mine, the first few pics are of my old D30, the D44 pics start in the second row.
http://fototime.com/inv/DFCDB9A8BDAF591

The LCA's are 19.5", and the UCA is 17.5". The mounting position on the axle is just as important as the position on the frame.

[RCP Phx]

I agree with not wanting to lose any clearance.Thats why I mounted mine high and inboard.Since I used a stock "sized" crossmember I didnt lose anything there.At the intersection of where my old lca mounts used to be I had to cut part of them away before I could put the new ones on,so I lost about 1" there!

completed long arm pics (http://hometown.aol.com/rpayne9421/index.html)

http://filebox.vt.edu/users/arebrahi/Jeep%20pictures/RCP%20Phxs%20pics/oPFn0Hr83xva2SWUSuDNUTfCoSXI5CR30180.jpg

[vintagespeed]

Originally posted by mad maXJ
so how long are your arms now? typical lifted XJ arms are in the 16-17 inch range, longarms are typically in the 32-36 inch range, so how long are yours?
I'll have to measure them again, but I believe they're 24-25", double JJ's, 1.5" x .288 DOM.

[CRASH]

proving there was an error in it's design.

Hmmm.......someone forgot to send me the memo.....mine seem to be going strong after almost 3 years.

CRASH

http://fototime.com/{944A28F5-0ED9-4E64-BCA0-CB6EBF333E74}/picture.JPG

[TOZOVR]

Originally posted by Ary'01XJ
RJ, did you really just ask this question??:rolleyes: There's this nifty function called a search button. USE IT! This debate has gone on at least 3 times in the past year lasting weeks. Oh that's right, you're not a naxja member, you can't search the old threads. Here's a hint.....JOIN! :D

Ary

P.S. I don't know how many people besides goatman are running "mid-arm" setups, but he can't seem to say enough good things about his.

Hmmm...Did Ary just give me a load of crap about a simple question?

Feeling a lil ballsy because you actually wheeled last weekend? :D


Goatman, the longer short arm setup is actually what I'm looking at doing...The fab part is no problem as I have an Ace in the hole fabricator located up the street who like Guinness about as much as me....I also get my RE stuff at Cost (so did Ary.... :flip:), so getting some Superflex joints and fabbing the arms shouldn't be a huge issue.

I'm curious about the ratio in length between the Short ams (say RE Fixed at 16.25 for the lowers) and the new Arms...should I add X% to the RE and then the same percentage to the Uppers...Know what I'm saying. It seems like a really simple mod that would help the ride and flex...

Thanks guys.

[ChuckD]

Originally posted by TOZOVR
Hmmm...Did Ary just give me a load of crap about a simple question?

Feeling a lil ballsy because you actually wheeled last weekend? :D


Goatman, the longer short arm setup is actually what I'm looking at doing...The fab part is no problem as I have an Ace in the hole fabricator located up the street who like Guinness about as much as me....I also get my RE stuff at Cost (so did Ary.... :flip:), so getting some Superflex joints and fabbing the arms shouldn't be a huge issue.

I'm curious about the ratio in length between the Short ams (say RE Fixed at 16.25 for the lowers) and the new Arms...should I add X% to the RE and then the same percentage to the Uppers...Know what I'm saying. It seems like a really simple mod that would help the ride and flex...

Thanks guys.

As far as figuring out the lenght of your new LCA's, first figure out where your going to mount them, then measure the distance from the frame point to the axle point. Keeping in mind you want a 101" wheel base. Think of the LCA's establishing the WB and the UCA's adjusting the Caster.

[MJR]

Originally posted by CRASH
Hmmm.......someone forgot to send me the memo.....mine seem to be going strong after almost 3 years.

CRASH

The early Bronco guys know about that radius arm bind. Someone just came out with a articulating axle for them Fords.

[CRASH]

Bind is your friend. I'll take my bind over the gimmicky, unrestricted articulation of wristed radius arms and the like, any day.

Limit the front axle a bit, and watch the rear axle come alive!

CRASH

[vintagespeed]

Originally posted by CRASH
Bind is your friend. I'll take my bind over the gimmicky, unrestricted articulation of wristed radius arms and the like, any day.

Limit the front axle a bit, and watch the rear axle come alive!

CRASH

Call me silly, but I disagree. :D Bind is what happens right before breakage and I'd rather flex my components freely than push them to their limit & hope for the best.

Also, if you map out the suspension arc of a radius arm (basically a 2 link) front suspension you'll see a ridiculous amount of caster change throughout the axle's range of motion. What I did with mine was to make the axle mounts (upper & lower) exactly twice as far apart as the frame mounts (upper & lower). If you map this out you'll see a very mild, by comparison, caster change through the suspension arc.

I can't take all the credit for putting this together Greg Gavel (C-Rok) and of course the Goatman helped keep me on track with the design & logic behind the layout. Without their advice I would've had lots of trial and error.

[Gary E]

I have only had mine on for one trip, but I am really digging them!

The improvement in the ride is amazing, it flexes really well, you would only want more if you were a ramp jockey. Actually mine is limited by the shocks, thankfully or my brake lines would be done.

I have rubbed along the bottom arm, better that than my DS thats an inch or two away.

Who cares about small caster changes when you are in 4lo? I had a little wobble before the LAs not anymore.

I rubbed a little on this obstacle, everything slid up fine and it hit the crossmember a little (it hangs no lower than stock)
http://home.comcast.net/~6mach9/soupbowl.jpg

It also climbs ledges much easier, of course my short arm angles were pretty bad at 6 ins of lift.

Personally I think a longarm setup is better and easier to fab. Its a win win situation.

[ChuckD]

Originally posted by Gary E
I have only had mine on for one trip, but I am really digging them!

The improvement in the ride is amazing, it flexes really well, you would only want more if you were a ramp jockey. Actually mine is limited by the shocks, thankfully or my brake lines would be done.

I have rubbed along the bottom arm, better that than my DS thats an inch or two away.

Who cares about small caster changes when you are in 4lo? I had a little wobble before the LAs not anymore.

I rubbed a little on this obstacle, everything slid up fine and it hit the crossmember a little (it hangs no lower than stock)
http://home.comcast.net/~6mach9/soupbowl.jpg

It also climbs ledges much easier, of course my short arm angles were pretty bad at 6 ins of lift.

Personally I think a longarm setup is better and easier to fab. Its a win win situation.

Come'on Gary, that obstacle had nothing to do with your Longarms, frt locker, or 4to1 TC, it was obviously your cool hood vents, :D

[CRASH]

Vintage,

You're really not hung up on caster change, are you? It's a non-factor, even when I'm blasting across Johnson Valley at 60 miles per hour, I never notice it.

To each his own, they all work about the same, and are miles ahead of the stock setup.

CRASH

[vintagespeed]

Originally posted by CRASH
Vintage,

You're really not hung up on caster change, are you? It's a non-factor, even when I'm blasting across Johnson Valley at 60 miles per hour, I never notice it.

To each his own, they all work about the same, and are miles ahead of the stock setup.

CRASH

Hung Up? Na not me, I never get hung up. I just TRY to build things correctly, as in "correct geometry", as in "as close to stock as possible", as in "not pushing the top of my axle into obstacles".

And yes, with the small amount of travel that we're talking about the changes are minimal. Burn me if you must. :flame:

[RCP Phx]

Thats an interesting thought since the factory set-up is flawed with its un-equal length/non-parallel arms!

[MrShoeBoy]

Has anybody with the long arms had a problem with blowing out upper control arm bushings on the axle end of the arm?

On my last trip to Tellico, my passenger side no longer had any rubber in the bushing and the driver side only had about half the rubber in the bushing. My arms are as follows: Long lower is 31.25" eye to eye with a JJ on the frame end and poly at the axle end. The "upper arm" is Rubicon Express adjustable upper control arms with a JJ on the "frame" end. Shocks are 17" compressed and 29.5 extended eye to eye. I have limiting straps in the front that limit the front shock travel to 29".

Does anybody have ideas on how I can get my bushings on the axle to life longer than one trail ride.

Thanks,

AARON

[REDXJ4FUN]

I have heard of this problem and am trying to prvent this on my long arm set up. Currie sells jonny joints that are supsed to replace the uper bushing and that should also help any bind but as it was said above a little bind is good. Mine has way tomuch damn flex up front and i'm trying to tightn it up so i can balance the front and rear.

[vintagespeed]

I'm really trying to understand the 'other side' of the coin with this "bind is good" theory. I think you guys are confusing BIND with COMPRESSION? Yes, when you run out of upward travel the rear will start to unload, but that shouldn't be caused by your suspension binding on itself and trying to break/bend itself apart it should be caused by the suspension not being able to move upward anymore, by hitting the bumpstops or sacking the coil. Or am I just out of my mind?

[JJ13]

I had a little too much "fun" tonight and may be way off, but I believe they are talking about bind at the bottom of their travel.

[RCP Phx]

Actually the only time you would have any type of binding is at full articulation(one wheel at full droop,one fully compressed)!This will happen with almost all suspensions using a "live" axle.

[vintagespeed]

Originally posted by RCP Phx
Actually the only time you would have any type of binding is at full articulation(one wheel at full droop,one fully compressed)!This will happen with almost all suspensions using a "live" axle.

Yes. Of course any solid axle suspension will eventually bind during articulation. (ugh, semantics) So which will bind first? Being that a radius arm can only flex at the frame ends, I'd say that it would bind before a 4 link and a 4 link would bind before a 3 link. And why do all the radius arm guys say "bind is good" ? Is there a reason that the Bronco guys (the original radius arms) have now gone from wristed radius arms to a wristed axle housing to alleviate the bind? :angel:

http://www.bcbroncos.com (under front suspension)

[RCP Phx]

"I" certainly dont like the idea of binding on "anything".In this game its all about compromise,you should have seen the bushings that just came off my RE short arms after one year.How much you have will depend on the design.I mounted my lowers very inboard(centered=no bind),so I should see much less than an outboard set-up.Knowing that I needed something to be able to move is exactly why I chose rubber for all the forward mounts and JJ for the crossmember.

[FarmerMatt]

Bind is good... well maybe not bind, but balance. Why do you think a lot of these guys are now adding currie antirock swaybars to their high dollar engineered low bind suspensions? They feel the need to balance out their suspensions & control the flex that they have. There is no other way to describe what a swaybar does, but bind the suspension. I read in a recent thread that C-Rok put his rear swaybar back on his custom rear suspension for the same reason. XJ's are known for their flexy front ends & stiff rear ends. The rear spring setup has more control over the body than the front. This is especially true with the newer flexier lifts on the market today. If you stiffen up the front (bind) to let it have more body cotrol you'll get the rear to work more for you & the rig will feel more stable because of it. I originally kept the stock rubber "C" bushing in my radius arms because they would distort & flex more than poly would, but the front end felt like it had no control over the body positioning. I talked about adding a swaybar, but than figured out that adding stiffer poly "C" bushing does the same thing. The rig feels a ton more stable on the rough stuff & I still max out 14" travel shocks in the front. My rear tires don't come off the ground nearly as much either. In short it's not about flex or bind really. It's all about the balance.

Sorry about this thread going the wrong way. This is supposed to be about those little dinky arms so we should all back off & let Mr. Goat & Vintage (web wheeler that hasn't even had his dinky arms out to wheel yet :) ) go back to their brain washing.

Matt

[RCP Phx]

Isnt that the truth,I had my RE4.5" kit last year complaining about the rear flex.I added some extended shackles,wow what a difference,it really added "balance" to the vehicle.

[Goatman]

I think Matt sumed it up nicely. I would add that the term "resistance" may be more accurate than "bind". The beneficial effect created by some binding, that is being discussed, is actually the resistance that is working on the suspension. That is also what the sway bar will do, add some resistance to balance things out and increase the stability.

I like Matt's idea of the stiffer C bushings on his radius arms, since it won't hurt anything and the life of the bushings should be very long. Unfortunately, the stock rubber bushings in the axle end of the upper control arms in most setups are not very durable, and can wear out quickly in a flexy rig or one with the typical long arm setup. They just need to be inspected regularly and replaced as needed......a simple process with the right tool. I got tired of replacing them, and didn't like the front axle wrap up that they allowed (especially when worn), so I went with JJ's when the D44 went in. Because the JJ's don't allow much bushing deflection, I only used one upper arm, which allows for very little, if any, bushing deflection (binding). I can get away with little or no resistance in the front suspension becuase my rear suspension is very soft, so things are still pretty well balanced. Those with a stiffer rear suspension, like BOR springs, need more resistance in the front to balance things out. They will also have more overall stability than I will, but I can stay a little more level through certain obstacles because of less resistance to any one wheel compressing fully. My point is that each suspension needs to be tuned based on it's own components and handling, what's right for one setup won't be right for another.

Another issue is that components need to be strong enough to handle the forces that are working on them. Long arms without rubber UCA bushings can/will rip off the mounts. Stock LCA axle mounts need to be reinforced or they can/will rip off. This is the down side of binding, but if the components are strong enough, some resistance can be a good thing. A soft durometer poly replacement bushing for the axle end UCA would be a very good thing for many people, but I don't think anyone makes one yet.

BTW, I'm glad to see an actual thread about mid-arms........maybe the mindless long arm craze is finally over. ;) :D :D

[XJEEPER]

Gman, not sure of the durometer but RE now makes a poly bushing kit to replace the stock rubber UCA/LCA bushings they use in some of their arms. FWIW

[vintagespeed]

Originally posted by FarmerMatt
.......we should all back off & let Mr. Goat & Vintage (web wheeler that hasn't even had his dinky arms out to wheel yet :) ) go back to their brain washing.........

Matt
That's MR. VINTAGE to you. :D

[FarmerMatt]

Vintage means old right?

Matt

[FarmerMatt]

Sorry... My wife corrected me. Vintage equals classic, outdated, & old. :)

Matt

[vintagespeed]

Yes, you're right. Vintage + Speed = Old air-cooled fast ass VWs that you're V8 would run & hide from. Old is good, bind is bad.

[RCP Phx]

Originally posted by vintagespeed
Yes, you're right. Vintage + Speed = Old air-cooled fast ass VWs that you're V8 would run & hide from. Old is good, bind is bad.

Now your talkin my kinda game!!!!