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Discussion Starter #1
i just built my first 4 link and i'm getting a lot of rear steer. how can i fix this. there are pics of my rig on a seperate post called "buggy leaf my coils?" . or am i getting worried over nothing. it's a off-road only rig. probably never see 20 mph anyway.

thanks guys
 

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what have you decided not to jump it now. i am pretty sure you will get it over 20 mph, but i am sure it will be in good fun. the best way to get rid of rear steer is longer locating links. the more flex you have, the more the axle is going to twist around. so the longer the links the less they steer. not a true answer but it is what i have noticed in the mock ups we have done. just my 2 cents mike
 

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I just tested out my rear suspension this weekend and it has almst no rear steer at all. You dan't have to triangulate both upper and lower like I did to get rid of rear steer. If you just triangulate the lower and put the uppers straight it will help also.
<IMG width=432 height=323 SRC="http://www.pirate4x4.com/ubb/uploads/Pa9270016.jpg">
<IMG width=432 height=296 SRC="http://www.pirate4x4.com/ubb/uploads/frostober1a.jpg">
 

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Has anybody thought about trying to make the links so that the body does not move so far of center when it articulates? Or beter yet, make it move the other way so the wieght will be on the up hill side.
 

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you mean having the roll axis plane and cg plane almost ontop of each other...yes i have thought about it as I am sure others have to. However, the problem I have encountered is space constraints. You can only move the rear roll axis up so much unless the rearend of the rig is just choped off.... <IMG SRC="smilies/fj.gif" border="0">
 

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Originally posted by desertoy:
<STRONG>I just tested out my rear suspension this weekend and it has almst no rear steer at all. You dan't have to triangulate both upper and lower like I did to get rid of rear steer. If you just triangulate the lower and put the uppers straight it will help also.
<IMG width=432 height=323 SRC="http://www.pirate4x4.com/ubb/uploads/Pa9270016.jpg">
<IMG width=432 height=296 SRC="http://www.pirate4x4.com/ubb/uploads/frostober1a.jpg"></STRONG>
Do you have any close up pics of your suspension links?
 

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Discussion Starter #9
Originally posted by Convertiyota:
<STRONG>I remember thinking that your links looked real short in your pics. Did you use tractor links??</STRONG>
yes, theyare tractorlinks. and about 30" long on all 4. my idea was carry one spare. but i'm also a semi novice builder so it ws also easier for me to do. but will the rear steer cause any real problems anyway. and as far as jumpin goes, i'll be goin straight anyways....i hope. but if i lengthen the bottom arms, it will help right ??????
 

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Originally posted by BeaconBasher:
<STRONG>do you run into any problems triangulating both upper and lower links?</STRONG>
Not so far <IMG SRC="smilies/biggrin.gif" border="0">
 

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I don't see how rear steer can cause to much problems. i say drive it and see how you like it if it bothers you fix it. I like desert toys rear end looks simple and effective
 

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From what I have read, the two ways to eliminate roll steer are 1)have the longest links you can fit, 2)make sure your roll axis is horizontal. Since you allready have yours done either option is a lot of work. I say just wheel it. If you don't like it you can allways change it latter.

Kev

P.s. Pig Pen- I told ya so!
 

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Originally posted by Pig Pen:
<STRONG>You can only move the rear roll axis up so much unless the rearend of the rig is just choped off.... <IMG SRC="smilies/fj.gif" border="0"></STRONG>

How do you mean? Please explain, and how it helps to havethe rear chopped off?

And what's your opinion on both sets of links being triangulated, especially for flex, stability, and road use. My coilover set up will be on the rear of a 90's style x-cab tubed out cab back. It will be my DD for a while.

what is the way I can find out my CG?
And desertoy How long are your links and at what angle is the uppers triangulated at (if you don't mind)

[ 10-16-2001: Message edited by: ToyFamily ]

[ 10-16-2001: Message edited by: ToyFamily ]
 

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just a dumbass question from me since i would like to 4 link mine, It seems like it would be necessary for the uppers and lowers to be the same length, am I right or stupid?
 

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Discussion Starter #16
Originally posted by ToyFamily:
<STRONG>
How do you mean? Please explain, and how it helps to havethe rear chopped off?

And what's your opinion on both sets of links being triangulated, especially for flex, stability, and road use. My coilover set up will be on the rear of a 90's style x-cab tubed out cab back. It will be my DD for a while.

what is the way I can find out my CG?
And desertoy How long are your links and at what angle is the uppers triangulated at (if you don't mind)

[ 10-16-2001: Message edited by: ToyFamily ]

[ 10-16-2001: Message edited by: ToyFamily ]</STRONG>
THANKS FER THE INPUT GUYS. I'LL DRIVE IT AND SEE WHAT I THINK.
 

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I can't remember off hand how long my rear arms are( I think between 40 and 50"). What I did was make the rear of the arms in line with the axle centerline and make the front of the arms in line with the center of the deiveline u-joint. That way I don't have to worry about the driveline changing lengths too much as the suspension works.
I kept the same wheelbase also, 105".
 

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Originally posted by ToyFamily:
[QB]
How do you mean? Please explain, and how it helps to havethe rear chopped off?

And what's your opinion on both sets of links being triangulated, especially for flex, stability, and road use. My coilover set up will be on the rear of a 90's style x-cab tubed out cab back. It will be my DD for a while.

what is the way I can find out my CG?
And desertoy How long are your links and at what angle is the uppers triangulated at (if you don't mind)
QB]
What I mean is that the rear half of the frame would have to yacked in order to mount the links high enough so that the roll axis would be in the same plane as the cg roll center.
As for triagulation, its hard to explain with out pictures but link, lenths, angles, & place all dictate how how the suspension will react. I remember awhile back Gordon put up some good pics of how to determine roll axis. Its a picture from the millikin book.
 

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Originally posted by rokcrawla:
<STRONG>just a dumbass question from me since i would like to 4 link mine, It seems like it would be necessary for the uppers and lowers to be the same length, am I right or stupid?</STRONG>
Not neccessarlily(spell check anyone??) You should keep in mind that driving on the road you suspension doesn't really move that much, so in my opinion that is something to take into consideration. Off road, say your suspension flexs out while you are crawlin, how fast are you driving????? Fast enough to feel a driveline vibe if you pinion angle chages slightly, highly unlikely.
 

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Pig Pen is right about needing to hack the rear off a vehicle with a link suspension. You can run one a stock vehicle, but the body and frame constrains how much benefit you get out of it. There is so much potential in a link suspension and the rear frame and body need to be designed around it in order to take full benfit of all your work. If you rub your tires on the frame or fenders now with leaf springs, there only going to rub even harder after you go 1/4 or coils.
Does anyone know if it is good to have a high or low roll axis height when rockcrawling? Does it matter at such a slow almost static speed?
Kev
 
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