4 Link / 3 Link Rear Suspensions

[dearthvader]

The biggest reason I want to switch to a 4-link setup is the stock leaf spring suspension is soooo stiff and bouncy that the cart is truly unpleasant over even small bumps. I'll be able to properly tweak the spring rate/stiffness with a 4-link and coilovers.

Originally Posted by slonomo

I agree guys, articulation off road is key. On road, not so much. I guess I'm wondering if one mostly drives on the road, why would you switch to a triangulated four link vs. the stock suspension? Isn't the idea of the 4 link to create articulation and independent movement of each rear wheel? On smooth roads you would not need this kind of movement?

Scottyb, what kind of carnage did you see on the 4 link that was not well designed? Was it from bind?

[Rooster59]

Good luck with your build slonomo. Designing is the toughest part.

Several local friends are big into the rock crawlers and have some pretty elaborate four link suspensions. The one thing that is extremely noticeable on all the vehicles is a large amount of body roll even at low speed. When they run a race on a closed course motocross type dirt race track it looks like a bunch of drunk Irishmen racing down a cobblestone street. Bobbleheads on four wheels. Not too scary if you have a wide axle track and a three point harness.

You might consider integrating a moderate size sway bar in your design.

[slonomo]

I'm not really looking for rock crawler type articulation. What I really am interested in is better ride and suspension action on rough terrain. I want a little bit of independent articulation, just enough to drop one wheel into a rut while the other wheel is able to stay put or even move up.

Here are my basic goals:

1.) rear wheel articulation 4-5" up or down independent of the opposite wheel
2.) rear suspension travel about 8" total
3.) ability to set the suspension up in the middle of travel (4" up/4" down)
4.) good amount of suspension movement with two people on cart, no cargo
5.) have a suspension stiff enough to not bottom out off road

[slonomo]

Does anyone have any videos of their rear link style suspension in action?

[scottyb]

Sorry no but I will give you this. If I did it again I would not tip my coil overs inboard. I did so because I was worried they would be too stiff vertical. And stiff was what I was trying to get away from. But as mentioned above i get a lot of body roll, especially with 2 people on board.

[NCPW]

Originally Posted by scottyb

Sorry no but I will give you this. If I did it again I would not tip my coil overs inboard. I did so because I was worried they would be too stiff vertical. And stiff was what I was trying to get away from. But as mentioned above i get a lot of body roll, especially with 2 people on board.

This is why I didn't tilt mine inward. I knew I'd get a softer ride and more articulation doing so, but wanted to avoid add much body roll as possible. I was after a smoother ride. Pretty much everything Slo just listed.

[NCPW]

Here's a few of my reverse- triangulated 4-link.

[slonomo]

Originally Posted by scottyb

Sorry no but I will give you this. If I did it again I would not tip my coil overs inboard. I did so because I was worried they would be too stiff vertical. And stiff was what I was trying to get away from. But as mentioned above i get a lot of body roll, especially with 2 people on board.

So mounting the shocks straight up reduces body roll?

[slonomo]

Originally Posted by NCPW

Here's a few of my reverse- triangulated 4-link.

So did this accomplish your goals? Hows the ride? Articulation?

[scottyb]

Angling the shock reduces their ability to carry weight or absorb vertical load. I hope I'm saying that right. Tilting them in board at the top (I think) makes for more stability. In the end I decided upon a panhard bar to eliminate any sideways movement I perceived. It works awesome off the road with the 25x10x10 dirt devils. You run across a field drinking from an open cup.