School me on building radius arms.

[Steiger Man]

Now, I have the fab skills and tools. But I do not know about the math and measurements involved.

I'm working on my sons truck after he rolled it. We're switching from 4x4 to 4x2. I picked up some 2wd beams that are 3-1/4" wider.

What I'm needing to figure out is, how to measure for the new radius arms and new cross member for them.As far as expected travel...I'll play it by ear and take what I end up with.

How long should the new radius arms be,should they be any longer and why?
Does the new cross member need to be wider too?

Any good links to study up on this stuff?

Thanks...

 

[doyouquaxu]

All I know is that you can mount the radius arms to the frame like stock, and ive seen people incorporate their mounts to a new transmission crossmember. Other than that, I'm no help, I'm an a-arm guy

 

[-Nathan-]

Go have a look at dezertrangers.com, lots of good info over there if you weed through it.

to answer your question, no the x member does not need to be wider.

The longer the arms, the less caster is affected through out the arc of travel.

To give you an idea, my radius arm design (not yet built) will be close to 40" long, however I am pulling close to 24" of travel out of my front beams.

 

[nooch450]

Ive got some good pics in my build thread (link in signiture) basically put the beams where you want them at ride height, keep beams level, make the trans crossmember with mounts or stand alone mounts. Then build the part of the Arms that will bolt to your beams, then connect it to the mounts with whatever material your using...