Suspension designs

[NJV6]

Hi all, ok bear with this ramble - many weeks of thoughts here

I have a chassis, front and rear coil sprung axles & mounts and an inclination to build. (must be road legal)

I have done alot of searching but not come up with anything in one spot that would suggest advantages and disadvantages of differing designs.

Such as 5 Link (eg rear 80 series)
3 link (eg front Prado, RR, GQ, 80 series)
3 link + panhard
Triangulated 4 link
A frame (RR)
X link (modified 3 link)

Possibly 5 link might be a bit unstable on the front? Rokhound - looking at your pics you have 5 link front?

I am not after extreme articulation but I have always been disappointed with standard 3 link Prado setups. having just taken the front of one apart, looks like the shocks are about 2 inch's to short for a starter. I suspect the arms may bind before that point is reached however.

Which leads me to mounts. RR's seem to flex pretty good in the front and have a pin mount on the chassis


where as the Prado, 80 series have the eye


Is one type more suited - the eye is good for more straight up and down but when articulation is req'd it also has to move sideways??

It will not be a daily driver - more a play vehicle. Ride well over rough surfaces at mod speeds, suitable to drive on the road. Wow what a post.

Does anyone have any good links they wish to share?

[turoa]

if it were me id go for range rover radius arms. If you do not do all the research and the maths work, it will end up very bad on road. Radius arms are just plain easy, and usually good onroad. But see if you can flip them ontop of the housing. flat arms = good

[Steve_t647]

Personaly I would try a

5 Link (eg rear 80 series) or a 3 link + panhard in the front the thing is these do limit artic more but there is not a lot of room

For the back I would go with a Triangulated 4 link

Possibly 5 link might be a bit unstable on the front? Rokhound - looking at your pics you have 5 link front?

Which leads me to mounts. RR's seem to flex pretty good in the front and have a pin mount on the chassis.

Suspension 4 link rear
http://www.rumblemotorsport.com/rodeo/suspension.shtml

4 link calculator
http://mysite.verizon.net/triaged/4link ... index.html

[swampa]

mine will be back on the road soon, 3 link on the front and 5 link rear, i prefer the 3link on the front for the stability at speed with good travel, dont care too much about the designs that are out there for the rear as long as it goes up and down, when it gets back i will get hold of you then and take you for a skid, give you some more ideas, karam... prado arms on front, panhard rods and all the rest of the arms are safari

[KiwiBacon]

Your naming is a little off.

Normally the panhard rod (sideways locating link) isn't counted and suspension is named on it's side profile.

The rangerover setup is (as Turoa has said) radius arms in the front and a four bar linkage in the back. 3 links is the name given to four bars where you find a single link (or A arm) in place of the usual pair of upper or lower arms.
I haven't seen any factory 3 link front ends (I'm sure they exist) but the safari-guard landrover one is a good example.

Radius arm setups are a no brainer for something that's simple and almost guaranteed to work. But they have a significant amount of roll stiffness built in, this helps stability and handling but gives less articulation than a 3 or 4 link.

With four bar linkages it's very easy to get the geometry wrong, resulting in a rig that hops with changing traction due to the wrong amount of antisquat. If you hear of a vehicle that humps rocks, this is what they mean.
To get them right is either copying something that works or buying some suspension text books and investing a lot of time reading.
Interstingly enough drag racers have screeds of information on the subject. Trying to keep traction off the line without hopping is a major concern of theirs.

[meatc]

Found this when I was reasearching for my toy build.

http://www.4wheeloffroad.com/techarticles/suspension/131_0306_four_link_suspension_part_1/

I have gone with basically a rangerover set up. radius arms and Panhard at front 3 link at rear with custom A arm upper link. Dont ask how it goes its still a work in progress
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[SupraLux]

With four bar linkages it's very easy to get the geometry wrong, resulting in a rig that hops with changing traction due to the wrong amount of antisquat. If you hear of a vehicle that humps rocks, this is what they mean.

This can be solved to a certain degree by making some adjustable-height chassis mounts for the top arms, allowing you to change the angle of the top arms provides you with the ability to change your anti-squat figure somewhat.

As for my advice - go with range rover radius arm front for stability, and 3 link rear + panhard (2 long lowers, one central upper - have a look at an Isuzu coil rear for an idea of what I mean - or just look at Riks rear end.

Steve

[skid]

Interestingly enough drag racers have screeds of information on the subject. Trying to keep traction off the line without hopping is a major concern of theirs.

this is true.

they can also set up thier cars to hook up both rear wheels without any form of locking device or LSD needed. Although this would be on the pavement and in a straight line of course (bit different to off road).

[NJV6]

From what I have read

5 Link (also called parallel 4 link + panhard)
2 lower locating arms, 2 upper, 1 panhard
rear 80 series, GQ etc.

(no panhard yet in this photo)

3 link + Panhard
2 lower arms, 1 upper arm
Thanks hiriklux for the pic


3 link
Same as and coil Rover front, rear Pajero, front 80 series, GQ
2 lower arms (located onto axle at two points each), 1 panhard. can be located upside down on top of axle.


Triangulated 4 link
No Panhard, 4 links to axle in triangle shape


A arm
Rover rear, doddzee's GQ


That is how i understand it - correct me if wrong

[NJV6]

That last post took so long to do there are 2 more replies!!

Thinking 3 link front now with upside down RR radius arms.

Rear either 5 link using 80 series links (saves loads of calculations) or A frame like RR.....

[ransom]

my 2 c worth
as a mountain bike suspension tech
a good copy of a design with bad geometry will perform poorly
a good system can be made better with a modern advanced shock absorber
the more adjustments you have the better and they more likely they will be set wrong
until ya do lots of measured test articulations and on/off road tests
four bar link gives nice almost vertical wheel path
curnott racing shox and of course fox shocks started as off road racing companys and now produce very high tech and solid gear
some of the stuff we get for bikes now has adjustable everything
high and low speed comppression adj rebound ,bottoming control and stable platform
which means the shock doesnt pogo after a hit just returns to neutral center
and can tell the difference between small hits and big impacts /landings
i see fox dampers for sale here
anyone know if the curnott shocks are here
homebuilt suspension is way cool some very cool pics and trucks on here

[SupraLux]

That last post took so long to do there are 2 more replies!!

Thinking 3 link front now with upside down RR radius arms.

Rear either 5 link using 80 series links (saves loads of calculations) or A frame like RR.....

I'd just copy Riks rear - 3 link + panhard - it works very very well, and if you keep the lowers as level as possible at normal rest then the rear-steer will be minimal. Its got 80-series lower rear links in the lower rear position and 1 single 80-series upper, centralised. Its hard to tell, but the brackets the upper link attaches to the cross tube on have several sets of holes so the upper geometry can be changed to 'fine-tune' the anti-squat.

Steve

[NJV6]

That last post took so long to do there are 2 more replies!!

Thinking 3 link front now with upside down RR radius arms.

Rear either 5 link using 80 series links (saves loads of calculations) or A frame like RR.....

I'd just copy Riks rear - 3 link + panhard - it works very very well, and if you keep the lowers as level as possible at normal rest then the rear-steer will be minimal. Its got 80-series lower rear links in the lower rear position and 1 single 80-series upper, centralised. Its hard to tell, but the brackets the upper link attaches to the cross tube on have several sets of holes so the upper geometry can be changed to 'fine-tune' the anti-squat.

Steve

Thanks Steve,
How does it handle at speed (100km/h) Bumps affect it much?
Std 80 series bushes in custom mounts?

[NJV6]

mine will be back on the road soon, 3 link on the front and 5 link rear, i prefer the 3link on the front for the stability at speed with good travel, dont care too much about the designs that are out there for the rear as long as it goes up and down, when it gets back i will get hold of you then and take you for a skid, give you some more ideas, karam... prado arms on front, panhard rods and all the rest of the arms are safari

Cheers Karam, we'll be in touch

[SupraLux]

Thanks Steve,
How does it handle at speed (100km/h) Bumps affect it much?
Std 80 series bushes in custom mounts?

Yes, standard arms with standard bushes. Mounts are custom, just some plate and some angle...

Handles really well actually - has a swaybar obviously, but it doesn't affect the twisting much...

Steve

[nivaman]

Lada's also come with 5 link rear end and get great artic. Independant front end as well.

[Steve_t647]

One reason I suggest the triangulated 4 link in the back is the twisting effect you can put on the diff under articulation with a 3 link. Are there any 3 link calculators, I have heard a few horror stories from 3 links spliting, kinking and twisting the diff housing.

Obviously they got it wrong I am wondering if this was all in the upper arm in the 3 link?

[KiwiBacon]

From what I have read

5 Link (also called parallel 4 link + panhard)
2 lower locating arms, 2 upper, 1 panhard
rear 80 series, GQ etc.

3 link + Panhard
2 lower arms, 1 upper arm

3 link
Same as and coil Rover front, rear Pajero, front 80 series, GQ
2 lower arms (located onto axle at two points each), 1 panhard. can be located upside down on top of axle.

Triangulated 4 link
No Panhard, 4 links to axle in triangle shape

A arm
Rover rear, doddzee's GQ

That is how i understand it - correct me if wrong

Including the panhard in the link count isn't right. A five link suspension system is actually a split double wishbone independent suspension setup.

Four bar linkage, triangulated four bars, the one you called "three link + panhard) and the rangie A arm are all four bar linkages and all behave the same under acceleration and braking. Look at them side on and you'll understand.

The radius arms aren't called a linkage, it's just a simple swingarm. Calling them 3 links confuses them with a rear A arm setup (triangulated four bar).

Ransom, there's a lot of BS in the mountainbike suspension world. There is not a single suspension system in production which produces a vertical axle path, they are all circular arcs or compound arcs.
The Curnutt style shocks are also enveloped in layers of BS, plaform dampers are not the holy-grail but if they were the curnutt design is not the best way to implement it either. Dished pistons and shim stacks are a much better way.

[NJV6]

Judging by the replies, I think most people under stood me

I'll try harder next time

Any Solid swap's I have seen done (internet - outerlimits, 4WDmonthly) on 4Runners, surf and Pajeros have been called 5 link!! And set up like I said above.

[swampa]

got a 4wd monthly video with a swb pajero, solid beam conversion, 44's, have you seen it, do you want to have a look?

[NJV6]

Seen in on outer limits. Is this the one?

[swampa]

thats the one, the video is interviewing the owner and going over the build, how he did things...

[SupraLux]

Judging by the replies, I think most people under stood me

I'll try harder next time

Any Solid swap's I have seen done (internet - outerlimits, 4WDmonthly) on 4Runners, surf and Pajeros have been called 5 link!! And set up like I said above.

I understood ya perfectly

Its kinda like what we drive - call it a truck, call it a 4x4 or a 4WD, we all know what we mean if theres a little description going with it.

So unveil a few more details on what you're doing here... got pics of the parts and some grand plan?

Steve

[Heath]

Holy shit...

That thing looks like a giant Tamiya remote control monster truck.

Or is it a pajero junior with daddy's tyres on?

either way - NICE.

[NJV6]

Yip here ya go Steve

Got this in the shed ($0)



+ got this on Monday ($250)



+ this last week



So mod the 1999 model LWB chassis.

O and it'll be on a Nibby & Steve time frame

[matwelli]

Hi,

Everyone has an opinion, but I have noticed on the yank sites such as pirate4x4 where they want good flex, but also good traction and still being able to drive on the open road - triangulated 4 link is the go.

There are calculation programs that you can adjust every aspect of the 4 link geometry to get a setup that will work.

[timotheus]

There are calculation programs that you can adjust every aspect of the 4 link geometry to get a setup that will work.

Has anyone got a link to any of them?

[lilpigzuk]

There are calculation programs that you can adjust every aspect of the 4 link geometry to get a setup that will work.

Has anyone got a link to any of them?

from this thread

http://www.pirate4x4.com/forum/showthre ... t=analyzer

gets this calculator

http://mysite.verizon.net/triaged/4link ... index.html

need a couple of beers too get my head round it

[timotheus]

need a couple of beers too get my head round it

Dont you just, thats intense.

Thanks anyway.
Tim.

[tpft]

i get chatter and bounce from rear end on steep hills when i hit bumps,
at the moment running leafs and decent shocks in c class zuk.

do u think going to coil over would help this?
it gets the whole rocking "lose traction gain traction" thing going on
front is custom coils and links and works good, rear end sucks i was hoping too somewhat tune it out for now............if possible.
i don,t think that much articulation is needed for a trials rig just predicatble
compression and rebound

thoughts?