A-Frame or 4 Link for Rear Susp.

[TWISTY]

A while ago I bought one of Dobbin Engineering's A-Frame Joints to install in the rear of my zook for when I got round to doing the wheel base extension. I had seen how well Mud4B's worked and thought it would be the best setup to run, so went out and bought the joint for $450, before doing much research into link setups.

Lately I have been doing heaps of reading on the net on Link Setups and have noticed that trianglulated 4 link is deffinetly the most common setup used. So I've started having second thoughts about installing the A-Frame.

So am just after some feedback on which setup would be better for the rear of my zook, A-Frame or TRI 4 Link, and why?

Just for info, the front will keep the 3 link + panhard setup it has now.

This was the best info I read....
http://www.pirate4x4.com/forum/showthre ... oll+centre

[redzook]

there basically the same thing and will behave the same

[Micka]

The only drama I can see with an A-frame is that there is only one point doing the work of two links in a tri4 set up. The geometry is pretty well the same...but for strength in high speed events or in high shock loads, the tri4 should be stronger.


Micka

[Loanrangie]

Why not use a rangie A frame ? cheap and the top mounts bolt in.

[mud4b]

my setup does work a treat... iwould not use small diameter tube for it though..as mentioned above it does have a hell of alot of stress on it..

as for the 4link... never used one, but the only thingi could see (depending on arm length) is that it could create more rearsteer
than the a-frame setup.

[TWISTY]

Yeah I've been thinking about it more too Mark, and your setup would have to be heaps easier to setup without getting any binding of the links.....so I think I will still be doing a similar setup to yours!!

[redzook]

Yeah I've been thinking about it more too Mark, and your setup would have to be heaps easier to setup without getting any binding of the links.....so I think I will still be doing a similar setup to yours!!

4 link and aframe are the same setup

work identical

[redzook]

as for the 4link... never used one, but the only thingi could see (depending on arm length) is that it could create more rearsteer
than the a-frame setup.

do u run straight lower links? or triangulated?

if there straight u would have the same amount of rear steer as a 4 link with straight lower links ( if they were the same lenght and angle)

[RUFF]

Yeah I've been thinking about it more too Mark, and your setup would have to be heaps easier to setup without getting any binding of the links.....so I think I will still be doing a similar setup to yours!!

4 link and aframe are the same setup

work identical

Generaly you can get the top links more centred with an A Frame.

If you allready have the link then you may as well use it.

Myself i wouldnt use an Aframe again. But its only because i find it easy to set up a true 4 link.

[redzook]

Yeah I've been thinking about it more too Mark, and your setup would have to be heaps easier to setup without getting any binding of the links.....so I think I will still be doing a similar setup to yours!!

4 link and aframe are the same setup

work identical

Generaly you can get the top links more centred with an A Frame.

If you allready have the link then you may as well use it.

Myself i wouldnt use an Aframe again. But its only because i find it easy to set up a true 4 link.

yes but u still work out roll axis, roll center and squat all the same

so there gunna work under the same princibals

[mud4b]

just my thought on the 4 link..

having 4 bushes on 2 top arms.

a-frame has 3...

ok the 4 link with the 2 top arms, all the 4 bushes have to flex.

on the a-frame, its already minus one bush, but the 2 bushes towards the centre of the chassis do not flex, so this eliminates 3 bushes having to force themselves. the swivel at the end of the a-frame can basically go as far as it wants without binding.

not saying a 4 link would not work as good as a a-frame (as mentioned above i have never had one) but i could see the a frame working easier.

[redzook]

just my thought on the 4 link..

having 4 bushes on 2 top arms.

a-frame has 3...

ok the 4 link with the 2 top arms, all the 4 bushes have to flex.

on the a-frame, its already minus one bush, but the 2 bushes towards the centre of the chassis do not flex, so this eliminates 3 bushes having to force themselves. the swivel at the end of the a-frame can basically go as far as it wants without binding.

not saying a 4 link would not work as good as a a-frame (as mentioned above i have never had one) but i could see the a frame working easier.

but in an aframe the upper link dosent pivot at the frame so the point on the diff has to do all the rotating

even so my bushes still have a fair amount of travel left in them its my coils that determin my amount of flex if i had them unretained it would flex similar to yours

so to answer ur question just got with the Aframe since u already have the joint

[JemmyBubbles]

As you have mentioned the diff pivot/joint in the A-frame setup experiences a lot of stress. What is the wear/longevity like in one of these with road/trail use ? Say for instance the dobbin one. Is it something that if well greased will outlast the vehicle or does it have a similar life to bushes.

There was a slammed low-lux on airbags parked next to me in the mall the other day. The inside of the tray was cut away and he had a triangulated 4-link (Uppers and Lowers were both triangulated .. links horizontal )in the rear with heim joints etc plus all the airbag tank/crap. I was so engrossed when looking at it I managed to slam and lock the shorty's door on my left index finger. My nail is black I am in agony. I have lance it 3 times with a needle and it still throbbs

So my conclusion is go with the a-frame or you may risk slamming your finger in a door as 4 links are distracting.

[-Scott-]

Novice comment here - apologies if it's too ignorant.

Wouldn't an A-frame place extra constraints on the rear roll centre, where a 4 link could design it somewhere else?

Scott

[Wendle]

Wouldn't an A-frame place extra constraints on the rear roll centre, where a 4 link could design it somewhere else?

Scott

yes.