Boomerang shaped rear shackles (1 Viewer)
- Thread starter mimkerman
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Tankota
SILVER Star
The only time I've ever seen them used is on the rear of YJs where they need to be that shape for clearance. Other than that I do not know of any advantage.
Its all in the mind.. The distance between pins remains the same, the spring does not know or care that the shackle looks like a boomerang..
its all the same
Its called anti inversion,or am i missing something here??
Anti Inversion
Yup,
ANti inversion---prevents the shackles from over-centering backwards
I heard good and bad about them, Not sure you need them if you have a good shackle angle anyway but they do look kinda cool
Yup,
ANti inversion---prevents the shackles from over-centering backwards
I heard good and bad about them, Not sure you need them if you have a good shackle angle anyway but they do look kinda cool
I'm sold.
rsbcruiser
SILVER Star
The only thing you will get besides the potential for shackle reversal is a weaker shackle. More flex and in this case that is not good.
Tankota
SILVER Star
I've seen inverted shackles on a jeep but never on a cruiser. Have you guys?
PS I always set up my suspension so the shackle at "rest" is at least a 30* angle (sometimes 45 if its long enough). That's my anti-inversion strategy right there and its has never failed me since I got the cruiser in 1992.
PS I always set up my suspension so the shackle at "rest" is at least a 30* angle (sometimes 45 if its long enough). That's my anti-inversion strategy right there and its has never failed me since I got the cruiser in 1992.
I have seen inverted rear shackles on a 60 
he recognized it quickly and lifted the truck up to snap back
he recognized it quickly and lifted the truck up to snap back
inversion
it can happen on 40s even when the relaxed shackle is at 30-45 degree it takes a lot of flex. i saw it at katemcy and was a pain trying to pry it back.
it can happen on 40s even when the relaxed shackle is at 30-45 degree it takes a lot of flex. i saw it at katemcy and was a pain trying to pry it back.
or is this what he is talking about??
these are from bud built and are used on minitrucks and 4runners with a sas so that the straight shackle wont bind during flex.
not a true anti-inversion shackle but is boomerang shaped.
just looks purdier
- Thread starter
- #15
they sure look like boomerangs to me
clearly the bolt hole distance is fixed, but i still have to wonder if the relationship of the spring movement with the boomerang shape will yield a non-linear result, and hence the reason behind the original question. if they are thick enough or made from a quality steel I find it hard to believe they would be any weaker than a conventional design....
clearly the bolt hole distance is fixed, but i still have to wonder if the relationship of the spring movement with the boomerang shape will yield a non-linear result, and hence the reason behind the original question. if they are thick enough or made from a quality steel I find it hard to believe they would be any weaker than a conventional design....
Tankota
SILVER Star
There will be no difference in travel between those and straight flat bar. Think where the bolts go in them, that distance is fixed and it doesn't matter what the shackle design is in between those two points, the spring bolt will move along a radius of the hanger bolt. The only diff is that the boomerang ones will start their travel at a different point on the (same) radius.
They are only used to deal with clearance issues (like in that pic that frame has a gusset that could be in the way during travel).
As for strength, I personally would go thicker on that than I would on a straight shackle of the same eye hole measurement. This is because it is easier to bend a 10" chunk of steel than it is an 8". Maybe I've got my physics messed up there but that just seems logical to me...at the moment...right now
Use em if ya want. It won't hurt anything (Ya might get annoyed with all the questions out on the trail)
They are only used to deal with clearance issues (like in that pic that frame has a gusset that could be in the way during travel).
As for strength, I personally would go thicker on that than I would on a straight shackle of the same eye hole measurement. This is because it is easier to bend a 10" chunk of steel than it is an 8". Maybe I've got my physics messed up there but that just seems logical to me...at the moment...right now
Use em if ya want. It won't hurt anything (Ya might get annoyed with all the questions out on the trail
)- Thread starter
- #17
now we are onto something
if the shackle goes into motion at a different "point in time" than won't the spring movement and therefore the geometry and ride be different? this gets right to the heart of the question. perhaps it is more akin to having a different shackle angle than shape....
if the shackle goes into motion at a different "point in time" than won't the spring movement and therefore the geometry and ride be different? this gets right to the heart of the question. perhaps it is more akin to having a different shackle angle than shape....
Tankota
SILVER Star
I just realized that no matter if you use straight shackles or boomerang the spring end is going to be in the same place and have the same arc of travel. I guess I made a mistake in my previous post :whoops:
