Random control arm questions (wanting to understand more)

AndyG

Because some other guys are perverts
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@mrblaine @jjvw @anybody that won’t contribute junk info or start a fight

1. Are radius control arms good, bad or dependent on design,etc?

2. what is with the crazy long arms on rock crawlers when you can only flex so much till you hit the fender ?

3. doesn’t caster change some with any control arm design during travel and do we care?

4. why is a Johnny Joint-clevite combo control arm so common and how do they perform short and long term

5. Why is there soooo much conflicting information?

6 . Is mechanical density a big factor in design - for instance a 3 link to miss the drive shaft , etc

7. A mid arm appears to be a longer trianglulated 4 link with a track bar , the most stable of all set ups it seems-is that a an accurate assessment

8. Who is a real mid line supplier ? JKS?

I really want to understand more conceptually , that is all. I know good connections are important, and of course strength and clearance, but beyond that I really don’t know a lot.

For example when is it a good idea, if ever, to replace only 2 with adjustable, etc.

It seems the suspension world is like the construction world- good products are out there but many people have no clue what they are doing with them. Like one construction guy said to me “I have all this knowledge.” He did- and it was all so incorrect. Pitifully. And his career proved it.


Thanks,
Andy
 
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I don't think it's ever a good idea to only replace two control arms with adjustable control arms. If you're lifting it, you probably want to have a full set of adjustable arms, after all, things are changing when you lift it.
 
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Thanks, will be watching this thread , work is wide open so I may be slow to acknowledge.
 
1. Are radius control arms good, bad or dependent on design,etc?

3. doesn’t caster change some with any control arm design during travel and do we care?

Radius arms change the caster as the axle moves up and down. This will disrupt the steering at higher speeds on rough terrain. The Savvy mid arm's front upper and lower arms are parallel to each other. Caster does not change as the axle moves. This makes high speed travel more predictable over rough terrain.

2. what is with the crazy long arms on rock crawlers when you can only flex so much till you hit the fender ?

5. Why is there soooo much conflicting information?
People have been conditioned to think long arms for the sake of long arms are inherently better. Basically...
... many people have no clue what they are doing ....
4. why is a Johnny Joint-clevite combo control arm so common and how do they perform short and long term
People have no clue what they are doing and they are cheap. Unless there is some need to maintain the orientation of the control arm, there is no benefit to mixing Johnny joints and bushings except to save money. But if the suspension travel is long enough to over-rotate the bushing, money isn't being saved.

6 . Is mechanical density a big factor in design - for instance a 3 link to miss the drive shaft , etc
The front is typically a 3 link because the engine is in the way of a triangulated 4 link without a track bar. Basically a packaging restraint.
7. A mid arm appears to be a longer trianglulated 4 link with a track bar , the most stable of all set ups it seems-is that a an accurate assessment

The Savvy mid arm does not use a rear track bar. Others might. And those ones are not triangulated.

8. Who is a real mid line supplier ? JKS?

JKS is on par with Metalcloak, maybe a little less irritating. I don't see a compelling reason to use either.
For example when is it a good idea, if ever, to replace only 2 with adjustable, etc.

...

Doing so is running the risk to cut corners.
 
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Radius arms change the caster as the axle moves up and down. This will disrupt the steering at higher speeds on rough terrain. The Savvy mid arm's front upper and lower arms are parallel to each other. Caster does not change as the axle moves. This makes high speed travel more predictable over rough terrain.


People have been conditioned to think long arms for the sake of long arms are inherently better. Basically...


People have no clue what they are doing and they are cheap. Unless there is some need to maintain the orientation of the control arm, there is no benefit to mixing Johnny joints and bushings except to save money. But if the suspension travel is long enough to over-rotate the bushing, money isn't being saved.


The front is typically a 3 link because the engine is in the way of a triangulated 4 link without a track bar. Basically a packaging restraint.


The Savvy mid arm does not use a rear track bar. Others might. And those ones are not triangulated.



JKS is on par with Metalcloak, maybe a little less irritating. I don't see a compelling reason to use either.


Doing so is running the risk to cut corners.
All good points. Appreciate your contribution for the forum 🤘🏽😎
 
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