Satchel link vs. triangulated 4 link

[Praufet]

As the title says. I was reading a suspension book of mine and it said the ideal 4 link for the rear is a satchel link. Looks a little easier to build that a triangulated 4 link. What are the advantages of one of the other?

[Tim Smith]

Bump to get an answer for myself too. I couldn't find anything that answered the question on Google, but I did notice that everything was aimed at roadracing. It might have something to do with articulation or funky geometry at the limits of travel.

But on a side note, if you give it some thought before you start, building a 4 link is about as easy as they come for link style suspesions, as far as building is concerned. I mean you have 8 simple mounts and 4 link that you can buy premade or cut and weld yourself, what is hard about that. Designing it right is where it gets tough.

What book are you reading?

[montezuma]

Originally Posted by Praufet

I was reading a suspension book of mine and it said the ideal 4 link for the rear is a satchel link.

For what? Baja? The hammers? Circle track? I don't think that there can be an "ideal" suspension for everything. What was the book referring too?

[Booger Weldz]

Originally Posted by Praufet

As the title says. I was reading a suspension book of mine and it said the ideal 4 link for the rear is a satchel link. Looks a little easier to build that a triangulated 4 link. What are the advantages of one of the other?

is a 'satchel' link like a watts setup?

[JohnnyJ]

If this is a real satchell setup, then it looks like a 4-link with the uppers parallel to the frame and the lowers triangualted with the convergance at the frame end.

You should be able to do a comparison to a traditional 4-link (triangulation top), the XX or James link (uppers & lowers triangulated) and the Satchel (lowers triangulated) using the 4-link calculator.

[Praufet]

That's it johnny. Where can I find the 4-link calculator?

[JohnnyJ]

here

[Praufet]

Any FAQ or guide for this? I still trying to figure out the orientation of the x,y, and z-axis. Trying to figure out how to orient the grid with the vehicle. Never really designed a suspension so I'm trying to figure out where to orient the ends etc. Any suggestions, sample suspensions etc.? Also what is the graph? Don't really get that.

[I Lean]

I built a similar arrangement before, but with longer links than that guy used on his Jag, naturally. It worked great, the only real downside is that it has as fairly low roll center--which can be moved up easily, just by triangulating the upper links to the top of the diff, and keeping the lowers triangulated. Sometimes the more-parallel uppers might clear stuff above more easily though, so it's a decent option to keep in mind.

[DSI]

i know nothing about inverted 4 links (satchell)

[Praufet]

If triangulating the uppers or lowers will locate the axle, then why does the 4runner have a panhard bar? I looked at my links and the uppers definately look triangulated.

[ErikB]

Originally Posted by DSI

i know nothing about inverted 4 links (satchell)

What DSI really meant to say is read this thread:
http://www.pirate4x4.com/forum/showt...ight=dsi%2Famj

Around here it got nicknamed the "DSI/AMJ" link setup. If you do a search on "DSI/AMJ" you will find several other threads discussing it.

[DSI]

Originally Posted by ErikB

What DSI really meant to say is read this thread:
http://www.pirate4x4.com/forum/showt...ight=dsi%2Famj

Around here it got nicknamed the "DSI/AMJ" link setup. If you do a search on "DSI/AMJ" you will find several other threads discussing it.

:whistle:

[ErikB]

Originally Posted by Praufet

If triangulating the uppers or lowers will locate the axle, then why does the 4runner have a panhard bar? I looked at my links and the uppers definately look triangulated.

They are not triangulated ENOUGH to be very effective and that combined with the fact that they are all mounted with bushings would make for very sloppy lateral control. Not to mention that the factory uppers are thin and designed primarily to be loaded in tension, not compression. If they were designed for both (which they'd need to be if they were used for the lateral control), they'd be heavier duty (as would the mounts).

The panhard makes for DIRECT lateral control, so that's why the factory uses it.

The panhard will fight the triangulated uppers because the panhard wants the axle to swing in an arc, but the tri-uppers want it to move straight up and down. This causes bind. The rubber bushings throughout allow for this bind though, to a certain extent. Plenty for the factory-designed amount of travel anyway.