Suspension Geometry

[bRIBEGuy]

Hey guys,

I'm mid way through my first rock crawler buildup (custom 4-link chassis & links), and had a few questions regarding the links & geometry.

I have my upper and lower links mounted to the chassis 2" above each other. From a side veiw, the link mounts are vertically parallel (that is, the upper link is mounted 2" vertically directly above the lower link). As such, the upper links are slightly longer (just over a cm........er, 1/2 inch) then the lower ones. Is this okay/correct?

At the gearcase/axle, the upper links go to a standard "Clod" style link post, and the lower links are mounted just vertically above the axle (where the stock clod metal axle brace attatches to). The rod ends/ball are all off of a T-Maxx.

The idea seemed to work well on paper, but is having some issues reaching full articulation. It's not bad.................it's just not an obscene 90 degrees either.

Any thoughts, comments, or suggestions would be greatly appreciated.

Thanx.

[firstumustcrawl]

you might not be getting alot of articulation because you arent running a 4 link that i think makes a huge difference i had a guy in at the shop today with his links moutned like your i beleive with out a 4 link and we dod everyhtign we could to to get the most ART out of it we had it doing probably like 75 degrees after really messing with it

[Destroyer]

I think he is running 4 links though. I tried that same setup and I think it doesn't get as much flex because the links are all on the very top of the axle, and too close together. Also, running slightly longer top links is fine. It will rotate the motors upward, which can help with ground clearance. I'd say try to locate the lower links farther away from the upper links if it's possible.

Destroyer

[bRIBEGuy]

Thanx for the tips guys. Yes, it is a 4 link set-up.

So having the links further apart (on the axle side) will create more articulation?

I'm just running a mock-up chassis right now, but I'm gonna likely fab up the "real" one outta 1/8" aluminum this weekend. I'll test it out there, and then see what the true results are.

[Destroyer]

Are you mounting to the inner brace hole or outer brace hole? Also, do the links hit eachother or any other parts when articulated?

Destroyer

[bRIBEGuy]

I'm mounting the link to the outer brace hole (closest to the wheel, not the side closest to the gearcase).

None of the links hit each other during articulation, but the upper links do bump the gearcase at what is now full articulation.

I origonally had the upper links mounted lower in the chassis (1.5" above the bottom links), but raised them a 1/2" to lessen this issue.

[Destroyer]

Ok, try putting a slight outward bend on the lower links to allow free movement past the gearcases. That should increase flex some. Your mounting positions seem okay, so just make sure they aren't hitting anything at any point in their travel, and that the rod ends aren't being moved past their limit.

Destroyer

[MudCow]

75 deg flex sounds sensible to me. The MudCow only gets about 70deg and this is very competitive in our comp scene.

BTW, how are you measuring the angle of articulation? By trig or is it just a guestimate?

[toyofast]

Originally Posted by bRIBEGuy

The rod ends/ball are all off of a T-Maxx.

If you swap out these for some of the larger Kyosho ones you might gain a bit more flex. The Maxx ends don't give as much angle as the larger Kyosho ones.

Like JK's Clod... My Juggy doesn't have crazy flex, about ~75* of articulation. Too much flex is bad and can't be well controlled in a Comp situation, for bashing it migh be fun and fine.