Want some opinions: 5 Link vs A-arm vs Trailing arm

[kevin quesenberry]

Starting to amass parts for a new project. I live here in So-Cal, so I'm looking to build an all purpose desert toy. It will have a VW type transmission with (most likely) a rotary motor. Heavy stuff compared to most buggies on this site. I am looking for input and opinions on rear suspension. What seems to work the best and why? I like the standard 3x3 arms, but I think that's mostly because it's what I know. Not to mention, they're pretty bulletproof. I'm open to most anything, but I'm hoping to get around 16" of travel. I am working on a theory. I see these monster sand guys with 20+" of travel, but they also weigh upwards of 3000lbs! I don't think you need that much travel if you don't have that much mass. I also don't think I am going to launch over road crossings (Dukes of Hazard Style!) to get on YouTube.

[Loboracer]

There's a thread in the suspension section where I asked to see what a 5 link suspension looked like ("Can I get a visual for a 5-link suspension") where a lot of guys gave a lot of great info as well as opinions as to what's best.... from my gatherings it iwould be either trailing arms or a-arms depending on your plans/abiliities. From what I can tell...the 5 link might be a little complicated and weaker... but a lot of guys had a lot of different opinions. I'll be going with trailing arms.

[kevin quesenberry]

Got to read that one. I've done 5 links on mid-engine sand cars, but not hardpack. Kind of complicated, but I always thought they had more points of failure. Never on my own stuff, I always had the 0-travel swing axle. Bouncy, but strong.

[kevin quesenberry]

O.K., I read the 5 link discussion. Now I may actually lean towards an arm rear in trying to get optimal travel and less cv joint issues. I think... Now I think my head may explode after reading all that info in one sitting. wow...

[K-fab]

Welcome to the wonderful world of brain strain and poof-kaboom!

They all have their good points, they all have their bad.

Sort of an in general comment - if you're not racing on short course stuff like stadium racing or a place like Crandon, look at A-arms or trailing. Stronger (in general!), easier to set up and such.

One big thing about five link setups is that they are one of the easiest to make parts for - ONCE YOU GET THE DESIGN DONE. It's five tubes with spuds. Not much gets easier than that.

[nutz4sand]

I myself am interested in this in the way that I have heard some say a five link can be STRONGER as it connects to the chassis in more places. More connection points means more strength there and if you use good hiems and strong bars for the links with a good solid hub design it does sound reasonable.

Or am I Nutz?

[atomicjoe23]

You are NUTZ, but I think you are right. . .the more connection points to the chassis the more the load is spread and the stronger the overall assembly should be.

I understand that more linkages adds to complexities and more parts usually means more weaknesses but in this case I don't think so. . .I don't see why a 5-link and a trailing arm set-up of equal construction wouldn't be equal in strenght or the 5-link even slightly stronger because the loads are distributed more evenly through the chassis?

I can see why someone would say an A-arm would be stronger. . .the fact that it is a structure welded together as a unit would make it more rigid and therefore possibly stronger (assuming a sound design to start off with).

[Bugpac]

I can tell you one thing, If the load is not put in the right spot, you ultimatley are placing more of the load into one bar, that spreading the load theory has a lot of calculations to be accurate...

[K-fab]

From experience, I found that the links in a five link system tend to get bent during tumbles and rolls. I have removed a couple on rocks too.

As far as a strength factor - yea, it's more spots over a larger area. All that's true. The issue is when you hit them (in a manner they're not designed for) and the bars bend.

But, as stated, the nice inexpensive factor is that it's just a tube - very easy to repair, carry spares and such.

[Bugpac]

Stress not spread out...