Radius arm basics?

[The_Lobbster]

Also no body cares about Johnny law

Well, I do. Guess I'm a minority

 

[skippy]

Well, I do. Guess I'm a minority

If you dig deep enough its probably illegal to ditch the factory style suspension to begin with....

 

[The_Lobbster]

If you dig deep enough its probably illegal to ditch the factory style suspension to begin with....

As long as the suspension replacing it meets or exceeds the strength of the OEM equipment, it is not. I think some 1/4 wall DOM would pass that easily.

 

[N-Smooth]

A standard setup would just be called radius arms.

I bet cutting your frame is against safety requirements. The point is if you say you want a swaybar for road manners nobody cares but if you say you're doing it to be legal, everybody is going to think you're weird. Also if you were really concerned about safety you wouldn't be driving a 30+ year old tin can- let's be honest.

 

[spaggyroe]

I'm assuming R.E. is Rubicon Express? I'm trying to find pictures of their arms to give me an idea. Are they the ones that the upper link turns in towards the middle of the axle instead of directly above the bottom mount?

Correct, rubicon express. Like @xj_nate said, you can look at a lot of XJ or TJ applications for inspiration. Not knowing the nuances of samurai's, you might have a hard time packaging that style of radius arm in there.

Regarding the sway bar, don't samurai's come with a factory sway bar? If so, can you make some disconnects for it?
Essentially all an anti-rock or similar is, is a sway bar with a light spring rate.
I've ran anti-rocks in off road rigs, and they can help in some situations, but they are a trade-off for on road driving. For an occasional off roader, I would personally run a standard sway bar with a disconnect. Especially on something as short and narrow as a samurai.

 

[The_Lobbster]

Correct, rubicon express. Like @xj_nate said, you can look at a lot of XJ or TJ applications for inspiration. Not knowing the nuances of samurai's, you might have a hard time packaging that style of radius arm in there.

Regarding the sway bar, don't samurai's come with a factory sway bar? If so, can you make some disconnects for it?
Essentially all an anti-rock or similar is, is a sway bar with a light spring rate.
I've ran anti-rocks in off road rigs, and they can help in some situations, but they are a trade-off for on road driving. For an occasional off roader, I would personally run a standard sway bar with a disconnect. Especially on something as short and narrow as a samurai.

Thanks for the info! I've been doing some digging. Just to verify, is this type of arm setup that you are suggesting? Wristed arms seem to be the go to for many Samurai guys. Even the Rocky Road Outfitters coil kit runs a wristed setup, but except that none of the joints are adjustable at all.

I'm trying to do as much reading and researching as I can. I found a thread from Herzog from 2004 showing some radius arm info from when he built his. I will do some measuring, but do to how the samurai frame has almost no arch on the front compared to a Jeep, I believe that the top links would be too close to the frame if they are crossing under it.

The samurai factory sway bars are garbage, which is why I was leaning towards something more similar to an antirock.

 

[spaggyroe]

Yes, that's the style.

There may be better options out there for your setup though. I agree with what herzog and ilean said, about using rubber bushings on the axle end.

 

[The_Lobbster]

I am looking into it to how I could, seems like a smart idea. I have these poly bushing rod ends for the axle side. Just need to figure out if I should do something different for the end, or if there is any sort of cartridge I could swap out. I wonder if any duroflex cartridges would fit in these.

Edit: Just called Metalcloak, they were of no help there. Guess the other option would just be to get a 1.5" OD rubber joint that's about 2 5/8" side or so, enough to fit in the housing. Just would want to make sure I got a good unit.

 

[The_Lobbster]

Also, I suppose I could always mock this stuff up with PVC eh?

 

[bryson]

I think you're thinking way too hard about all of this. Run a very simple radius arm setup like on the front of solid axle, coil sprung Toyota Land Cruiser, or a solid axle, coil-sprung Land Rover and be done with it. If you feel the need for a swaybar, simply use the OEM Sami parts and be done.

For bonus points, use factory arms from the Cruiser or Rover and then all you have to do is build some VERY simple mounts on the axle and frame. That way you've got easily available replacements if needed, and a grundle of aftermarket upgrade options if you want.

 

[spaggyroe]

What he said. Those radius arms would add some style for sure. The "under the axle" mounting would probably be a good way to go too, as it could free up some space to mount your coils / coilovers.

 

[spaggyroe]

Also, curious about what makes the sammy sway bar junk? I have no experience with them. Are they just considered junk off road, or is there something about them that's a bad design?

My current early bronco was not equipped with a factory sway bar. I added a hellwig and really like how it has helped it behave on the road.

 

[The_Lobbster]

Also, curious about what makes the sammy sway bar junk? I have no experience with them. Are they just considered junk off road, or is there something about them that's a bad design?

My current early bronco was not equipped with a factory sway bar. I added a hellwig and really like how it has helped it behave on the road.

Very small, bushings are small and I don't believe you can even buy them anymore, unless somebody sells a universal one that will fit. With a 4" or so lift too, the bar will need to either be dropped in the front, or some sort of crazy extensions made. I mean, I do have one, and I can definitely try it out to see if it'll fit or not.


As far as the rover/cruiser arms, that looks like a great option. One thing I would personally desire, would be the ability to adjust them somehow though, so I could change caster angle if I wanted. My reasoning being, if I wanted to run an 10" coil or so, but then decided I wanted some more height, I could swap in a 12" or 14" with ease, and then simply readjust the caster to account for the extra height. I will definitely look into it more though. Wonder if I could run some sort of cam bolt to allow for that. I do like the idea a lot of having it hung down below to make more room for the coil pads though.

Alternatively, I could just set it up with the axle brackets installed on bottom and bolted into the arms connected at the frame, set my height, measure for coils, rotate the axle as needed to choose my caster, call it good, and never touch the suspension height again. Which is probably my best option I suppose.

 

[spaggyroe]

I believe there are a lot of options for caster correction on an 80 series landcruiser, so if you simulated the toyota style axle mounting and used those radius arms, you probably wouldn't be painting yourself into any corners.

 

[The_Lobbster]

Good to know, I suppose for how many there are out there that would make sense. So, does anybody happen to have a set of FJ arms they wouldn't mind selling, or at least letting me borrow for a bit for some mockups? @bryson are those ones in your picture yours, being used?

 

[Herzog]

With radius arms, your axle becomes the swaybar

 

[I Lean]

Very small, bushings are small and I don't believe you can even buy them anymore, unless somebody sells a universal one that will fit. With a 4" or so lift too, the bar will need to either be dropped in the front, or some sort of crazy extensions made. I mean, I do have one, and I can definitely try it out to see if it'll fit or not.


As far as the rover/cruiser arms, that looks like a great option. One thing I would personally desire, would be the ability to adjust them somehow though, so I could change caster angle if I wanted. My reasoning being, if I wanted to run an 10" coil or so, but then decided I wanted some more height, I could swap in a 12" or 14" with ease, and then simply readjust the caster to account for the extra height. I will definitely look into it more though. Wonder if I could run some sort of cam bolt to allow for that. I do like the idea a lot of having it hung down below to make more room for the coil pads though.

Alternatively, I could just set it up with the axle brackets installed on bottom and bolted into the arms connected at the frame, set my height, measure for coils, rotate the axle as needed to choose my caster, call it good, and never touch the suspension height again. Which is probably my best option I suppose.

I too wanted adjustability, so this was my solution. I use rubber bushings at all points, but the frame attachment is in a threaded housing. That adjusts the axle forward/backward. For caster adjustment, I did a sorta-cam-bolt idea, but it's not as easily adjusted as a cam. The slotted hole is the same type of thing, but I just have a rectangular "washer" to set the location within the slot.

 

[The_Lobbster]

Wow, those are some beefy looking units! What kind of joints are you using on the frame side there?

 

[bryson]

The arms pictured are not mine, but I do have a set of 80 series Cruiser arms that are not currently being used. Shoot me a PM and we can discuss.

 

[I Lean]

Wow, those are some beefy looking units! What kind of joints are you using on the frame side there?

Frame and axle side use the same bushings, which are lower control arm bushings for a mid-90's Dodge truck. They are the same outside dimensions as a Jeep TJ/XJ/ etc. bushing, so they pressed into Teraflex forged housings.