fixed or adjustable caster on radius arms

[magic carpet XLT]

so i'm going to be building a set of radius arms here pretty soon. they aren't going to be anything special, but i've been thinking about ways to creatively make built in adjustments to fine tune caster down the road. then i remembered seeing that nearly every single desert truck with radius arms has fixed caster.

is it worth it to build in some kind of adjustment for caster?
what is a good caster number for a fullsize van? i'm thinking 5-7 would probably be good
on kingpin beams, is there any built in adjustment to fine tune the alignment? similar to TTB alignment cams

excuse the basic ignorance, i'm new to this whole 2wd thing...

[SteveG]

[quote="magic carpet XLT"]is it worth it to build in some kind of adjustment for caster?/quote]
Not in my opinion. There have been a very small handful of caster adjustable beam trucks out there but they are few and far between. I say build it right the first time (fixed caster) and be done with it.

Then again, if you feel like experimenting and have the time... why the hell not. Maybe you'll teach us something.

[magic carpet XLT]

Then again, if you feel like experimenting and have the time... why the hell not. Maybe you'll teach us something.

it wouldn't really be that hard. i've already thought of two ways actually.

method one would be similar to the aftermarket radius arms on jeeps with a fixed length lower and an upper link heimed at either end. turning the upper in or out would set your caster. this requires a lot of extra heims, bracketry, time and i feel is a little too complicated.

method two would be to either make a misalignment spacer with an eccentric hole in it, or cut out an eccentric cam that would be incorporated into the bracket for the frame side. this would take some custom water jetting and CAD work which i can't really do, and probably only net a +/- 1 degree adjustment so not really worth it. it could also possibly be knocked out on a really hard hit i suppose.

i like your adivce steve, i think i'll just go with fixed. i'm not gonna be beating the crap out of it so if its solid it should last. down the road i will probably swap a TTB in, and i can make super baller arms then.

does anyone know if kingpin beams have any adjustability built in?

[ChaseTruck754]

does anyone know if kingpin beams have any adjustability built in?

They don't. A little of the caster is built into the radius arms, but the vast majority of it is built into the end of the beam. If you have a set of these beams lying around it's easy to see what I am talking about.

As for the adjustable caster - the 1st way you described doing it is how I would IF I were to go for adjustable caster. I, like most others am lazy though and just stick with the "normal" route. 5-7* is good for me.