Can anyone enlighten me on what the pros and cons are to mounting your front radius rod/hairpin/wishbone to the frame below via a bracket, or through the center of the frame itself. I've seen it both ways, just not sure what would be affected by doing it one vs the other. Thanks in advance
radius rod mounting spot
- Thread starter TrueBlue
- Start date
choppinczech
Well-Known Member
Mine started out in the center but moved down to sit level and keep the built in rake of the wish bones.
you the best Spanky
Hackerbilt
Active Member
My opinion differs I think from many.
I think the "proper" axle (lack of a better term!) is a straight line between kingpin centers. Those are, after all, the important bits around which axle design is centered. A dropped axle is 100% viable and for many cars 100% necessary...but it is changed from the straight design simply for clearance and/or ride height considerations.
Not because its an improvement.
This brings with it some complications.
Heres where it gets interesting. (or boring)
For style and looks a true straight axle will have the frame pivot point of the 2 axle locators (hairpins, split bones etc...4 bars are different) exactly at axle height. This looks best because the locators are level with the road surface and also keeps the up and down movement of the axle at the smallest variance of the locator arc of movement and helps prevent bumpsteer. Awesome.
Now...If you use a...6" dropped axle for example...you still run the locators parallel to the road surface because thats how it looks correct.
But is it?
The locator frame mounts are now 6" below the center of the kingpins. Now they are causing increased variance in arc because the pivot is no longer at the same height of the kingpins.
You can run the pivots at kingpin height and it will work better...BUT it doesn't look nearly as good with the locators running uphill.
OMG...what do you do!?!?
Just pay attention to how and where you mount your steering so that you limit your bumpsteer effect and either way is fine.
So why even bring it up?
Because it illustrates just how geometrically complicated our "simple" little T's really are. You just gotta pay attention to EVERYTHING thats all. LoL
What will decide the final location for your splitbone, hairpin etc pivots is the layout of your frame and how it relates to the particular axle you use. It will all fall into place with a frame mockup to completed ride height and setting the axle caster position.
Usually not too complicated once you see it all laid out.
I think the "proper" axle (lack of a better term!) is a straight line between kingpin centers. Those are, after all, the important bits around which axle design is centered. A dropped axle is 100% viable and for many cars 100% necessary...but it is changed from the straight design simply for clearance and/or ride height considerations.
Not because its an improvement.
This brings with it some complications.
Heres where it gets interesting. (or boring)
For style and looks a true straight axle will have the frame pivot point of the 2 axle locators (hairpins, split bones etc...4 bars are different) exactly at axle height. This looks best because the locators are level with the road surface and also keeps the up and down movement of the axle at the smallest variance of the locator arc of movement and helps prevent bumpsteer. Awesome.
Now...If you use a...6" dropped axle for example...you still run the locators parallel to the road surface because thats how it looks correct.
But is it?
The locator frame mounts are now 6" below the center of the kingpins. Now they are causing increased variance in arc because the pivot is no longer at the same height of the kingpins.
You can run the pivots at kingpin height and it will work better...BUT it doesn't look nearly as good with the locators running uphill.
OMG...what do you do!?!?
Just pay attention to how and where you mount your steering so that you limit your bumpsteer effect and either way is fine.
So why even bring it up?
Because it illustrates just how geometrically complicated our "simple" little T's really are. You just gotta pay attention to EVERYTHING thats all. LoL
What will decide the final location for your splitbone, hairpin etc pivots is the layout of your frame and how it relates to the particular axle you use. It will all fall into place with a frame mockup to completed ride height and setting the axle caster position.
Usually not too complicated once you see it all laid out.
...
Neshkoro
Well-Known Member
Opinions are like belly buttons. We all have one.
So, here’s my belly button. Maybe I’m all wrong here but I think when using an axle with wishbones it’s the wishbone angle that sets the caster angle of the axle and kingpins.
when using hairpins or a 4/link setup you can adjust the caster by adjusting the heim joints or clevis at the bat wing meaning that the rear attaching point is not as important.
So, here’s my belly button. Maybe I’m all wrong here but I think when using an axle with wishbones it’s the wishbone angle that sets the caster angle of the axle and kingpins.
when using hairpins or a 4/link setup you can adjust the caster by adjusting the heim joints or clevis at the bat wing meaning that the rear attaching point is not as important.
Dan the Man
Member
You just want to have the mount point as close to the steering arm if you are using a Vega type steering box. This will minimize the bump steer. I would never drill through the frame if I can avoid it. If you drill through the frame I would use a thick bushing or sleeve and weld that in place.
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