rear suspension links question?

[farva707]

so i just recently bought a twin hammers and im in the process of building it to my liking, ive gotten a gcm front plate and rear truss. still waiting on shipment but i wanted to get some more parts together while i wait. so im focusing on the rear links, uppers for now. id like to make some links from axial tubes or something similar. has anyone done this? my question is what length links and size ball ends did you use? part numbers if possible? thanks in advance!

[Sr.Irie]

Many have done this as well as myself with all sorts of different rods and rod ends. I always use the Hammer rod ends just so all the ends on the rig are the same, makes carrying spares easier. As for length start with the same length as the factory ones and just experiment, pinion angle can change torque twist.

[Pagu]

Hi guys, maybe i am slowpoke, but i noticed something.
If we look at yeti or rock rey rear lower links, they are | |, but TH lower links are like \ /
Also if we look at 1:1 rock buggy or trophy truck, their rear lower links are almost parallel.
Maybe it is a reason why TH's rear suspension work on high speed not so good? It looks more like scx10 suspension with \ / lower links.
Or it doesn't matter? What do you think guys?

[89redranger]

Originally Posted by Pagu

Hi guys, maybe i am slowpoke, but i noticed something.
If we look at yeti or rock rey rear lower links, they are | |, but TH lower links are like \ /
Also if we look at 1:1 rock buggy or trophy truck, their rear lower links are almost parallel.
Maybe it is a reason why TH's rear suspension work on high speed not so good? It looks more like scx10 suspension with \ / lower links.
Or it doesn't matter? What do you think guys?

What you're noticing is the triangulation in the trailing arms. And you're absolutely right. A double triangulated setup will have a lower roll center than a setup using parallel lower links/trailing arms (assuming all else is equal). It doesn't necessarily mean the performance at speed suffers. It just means that the chassis and torque have a greater influence on what the rear suspension does. Tuning will do a lot for the roll that is experienced.

I've actually been hypothesizing over a custom build (TH based) using a chassis built around parallel, or almost parallel) lowers in the rear. With the factory tub though, it just won't happen.

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[Pagu]

Thanks for answer! Glad to know for sure that my suggestion was right.
Then i dont understand why nobody made custom bild or upgrade kit with parallel lower links yet
What will be your custom bild? Scaler, prerunner or rock buggy?

[89redranger]

Originally Posted by Pagu

Thanks for answer!

What will be your custom bild? Scaler, prerunner or rock buggy?

No problem.

I'm not sure if I'll follow through with it or not but, I would be shooting to build a 1.9 Trophy class U4 car. Not a replica or anything like that. More of a compilation of a bunch of ideas and theories.



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[Dbx]

Originally Posted by 89redranger

What you're noticing is the triangulation in the trailing arms. And you're absolutely right. A double triangulated setup will have a lower roll center than a setup using parallel lower links/trailing arms (assuming all else is equal). It doesn't necessarily mean the performance at speed suffers. It just means that the chassis and torque have a greater influence on what the rear suspension does. Tuning will do a lot for the roll that is experienced.

I was reading up on roll centre just recently, having dramatically shortened my scx links. I don't quite see how the lower link width or parallelism effects roll centre - ?. I understood it that more triangulation is generally better. Vaterra seem to think this too. I can see how more triangulation of the lower links will give more axle steer. I found this post helpful: Another 4 Link Thread

[SkiSteve]

I don't know anything about roll centre, but without the triangulation in the rear you would end up with a lot of lateral flex out back. The joints would need to be designed to resist it instead. Having it triangulated helps keep things simple?

[Pagu]

Chevy Power Manuals from MJ - Pirate4x4.com Red Star Member's Photo Gallery @ http://www.pirate4x4.com/forum/gallery
Found something about roll center.
ChevPowerManual07 and next pages are about linked suspension. Reading and trying to understand atm

[Pagu]

I understand something, in few words:
Roll axis should be high. If lateral force is higher than roll axis, the vehicle will roll over.
Stock vaterra rear suspension gives very low roll axis. Rear truss upgrade rises roll axis. In theory parallel lower arms will rise it even more.

So 89redranger is completely right. If you want to understand why, just use my link

[Dbx]

The link didn't work btw.

[zumzum5150]

Can't comment on the configuration of the links but I've been using these BoomRacing lower and upper links without problems..adds bling to the rig