Suspension Unloading Uncontrollably
 

I just did a rebuild of my AX-10 using a new narrow chassis and Shorter but better Maxx Shocks. The angle of the shocks looks great and I am using extremely soft springs in the front and soft springs in the rear. Travel is relatively minimal (compared to a stock chassis).

When I climb into an extreme twist, the front carries a wheel nice and predictably... then sets it down softly, but at about the same time as the front tire touches down, the rear unloads too fast and flips the truck.

I tried moving the top of the shocks out farther, which straightened up the shocks some, but that made it flex less and roll over easier.

I'm going to try moving them in farther, but I can't go in much mor ethan I was.

Will thicker oil help in this case? How about softer rear springs? Will a change in the front effect anything positively in this case? I'm just racking my brain trying t figure out what I can change without changing everything :shock:

Yes and yes. Either can effect this for the better but personally,I'd try the thicker oil first. Without knowing what valving is in your shock currently,it's kinda hard to nail down what would be best. Try to bump the weight up 10 or 15 at a time. If your running 30 weight,try 40 or 45 first. See what that does and go from there.

i like stiffer springs in the front cause thats where you need the most traction, i have 50wt oil in my 4" trax biggies and it does real good it will carry a wheel sometimes but it never just unloads and it very predictable

It's funny to see how everyone prefers a different set up.8) I personally like to add weight for traction and super soft springs. I like to tune each corner with oil to control the loading/unloading. Currently,I'm running a different weight at each corner. I like it really well right now. I had to adjust it some after I switched to my finished chassis design,since the weight got moved around a bit. Seems to flex great and it's pretty predictable when carrying a tire over gaps.

Some strange things I am discovering...

I started the build with medium springs. They unloaded too fast and would flip me. I then went to soft springs in the rear. The flex was awsome, but then I had the twist issue when going steep and flexing up.

So I just tried stiff springs out of despiration, and they seemed to be an improvement. They didn't unload too fast because they never completely loaded in the first place... and they resist twist when climbing. The rig doesn't seem quite as balanced... but it seems a little more stable (If that makes sense)

So now I'm wondering if the soft or medium spring with thicker oil would do about the same. Oil keeps things from happening fast, but twist is kind of a slow action. I don't think oil would resist much... but it would slow down the sudden unloading with the medium springs maybe.

I have some 60wt. coming in the mail. I guess I'll see soon enough, but what do you think... what's more predictable... a stiffer spring or thicker oil?

I would go with the oil. If you still have torque twist with the soft springs try to preload the one that needs to be stiffened. I that doesn't quite get you there then just replace the one spring with one stiffer."thumbsup"

Sounds like your on the right track though.;-)

Me personally,I've run oil from 30 weight all the way up to 1000 weight. Different shocks,different angles and different weight all play into it.

8):ror:

I finally got it worked out. Went to the WWC this morning and ran a few packs through. I started with the stiff springs that did well here on the little rip rap that lines my creek bank and They were horrible. So I switched back to the really soft rear springs and they were perfect for the big rocks. All the unloading issues I had with the med. springs are gone, the fex is buttery smooth, and I was pulling lines with the new chassis that I doubt my stock cahssis could have done. No twist issues either.
"thumbsup""thumbsup"

My set up works great but might not work for you.
4oz wheel weights in both front, i run 8 cell saddle on the front axal too.
soft springs with 50 weight front.
rear medium springs with 80.
2oz of weights in each rear.
4 link front and rear.
I have almost zero twist, smooth as butter.

Weight?
 

Harvo, you never said what weight you are running. Adding weight to the wheels has a dramatic effect on keeping the dirty side down.

also, what brand of shock oil, too? i have noticed that there are differences between associated oil and losi oil.

Each of my front wheels weighs a pound and each of my rears are 12 oz. Weight wasn't really the issue.

Stock, I was running hard rear springs and soft fronts and it worked great. The narrower chassis and the front 4 link changed the dynamic some though. I switched to super soft springs in the front, and when I did, I thought medium springs in the rear would get me back to where I was stock.

It wasn't the case. The superior geometry of the new chassis over the old, and the double triangulation that I gained from the swap required that I use an even softer spring in the rear than I thought I would need. I never would have imagined I could use such soft springs with no twisting issues.

I also know now that I need to test on the kind of rocks that I compete on. The rip rap that they use to line creek banks and prevent erosion are not a good test. Neither are couch cushions :shock:"thumbsup"

Axial 30wt front

Assoiciated 60wt rear