Shock Mounts on BJv4 Chassis

[cpercival]

I’m having a hard time figuring out how to mount the stock shocks to the chassis; specifically, how far out to space them. Right now, I’m using the plastic balls from the shock tree, with a plastic washer (also from the tree) on the other side of it. The angle of the shock coming off the chassis seems to be too great and it’s hindering the shock from pivoting any further outward (laterally) and rotating. You can see it in the first pic. The top of the shock eye is jammed against the inside of the ball and the bottom is jammed against the outside. It’s actually worse in the rear, but it was easier to get this picture. Seems like I need to add more spacer, but it already feels like they’re hanging too far out there. In the back, the shock is actually sticking out past the cab, which I thought was not supposed to happen with this chassis. I remember reading somewhere that the rear shock was supposed to be nice and tucked in under the cab. I threw up some other pics so you all can see how everything is currently set up. Maybe I’m doing something else wrong.

These are stock shocks, Chaotic Crawlers ti links, and the axles are not clocked (middle).

Thanks for any advice. Without a local shop nearby and without any friends into rc, you guys are all I have for help.

[cpercival]

One more for good measure:

[001Hulk]

Im running the same chassis but with traxxus big bores. I think your problem is in the stock shock. Wicked wolf sells shock caps that have been threaded for a bolt and rod end to replace the eyelet on the stock style caps. Thats the only thing I can come up with that will give your shock more mobility. I know "buy another set of shocks" isnt what you were looking for but thats all I got!!

[ittybitty]

That's exactly how I had my STOCK shocks mounted on my BJV4 when I had it. I didn't use the plastic washer like you are though, and I can't remember if I put the flared end to the outside or the inside. There's some differences in how tall yours sits, and the angles that your shocks are oriented, but those shouldn't make too much of a difference in what you're talking about. I don't know if your wheelbase is short or what...but look here:

There isn't anything wrong with the stock shocks...just wanted to throw his out there since there are A LOT of opinions on which shocks are best.

Edit...I just noticed in the first pic that based on the mat you have your rig sitting on it looks like your wheelbase might be up to .5" short and really looks like the rear is what's short since the rear shocks are the ones that are standing up so tall.

[cpercival]

I didn't use the plastic washer like you are though, and I can't remember if I put the flared end to the outside or the inside.

The shock eyes on these are so big it seems like you would need something on the inside of the ball to keep the shock from sliding all the way inboard. Definitely need something on the outside to keep them from popping off. The plastic balls definitely do not hold the shock on. Maybe the angle of the shock coming off the chassis would be enough to keep them from sliding in. I'll have to try taking the washers off when I get home.

There's some differences in how tall yours sits, and the angles that your shocks are oriented

Definitely different looking than mine. Wheelbase is set by the length of the lower links, right? I'd have to bend them to lengthen it? I'll also do an eye to eye and compare to others. These are straight from the chaotic crawlers bag to the chassis so I haven't messed with them at all. Weird

[cpercival]

Update:

Taking the plastic washers worked. It freed up the inside of the shock eye to allow it to move more freely. The other thing I figured out was that the plastic balls are somewhat tune-able. My concern was that if I took the washer off the inside of the shock eye, there would be nothing to prevent the shock from sliding inboard. The plastic balls were just too loose to hold the shock securely. I’m not sure if they were intentionally designed like this, but I figured out that the more you tighten them down, the tighter they fit in the shock eye. Maybe they’ll end up splitting or just not doing the job as I need them to, but for now, they seem to be working. I have to use a pretty good amount of force to make the shock jump off the plastic ball, but they still move smoothly. Time will tell I suppose.

As far as spacing goes, I’m using the balls that came with the Traxxas Revo ends. I think they’re around 6 mm, and they seem to allow the shocks to articulate, but still keep them nice and tucked in under the cab in the back.

Also, my wheelbase seems ok. I think in the first pic, the shocks were not compressed at all, and it was sitting pretty tall. Not sure how you officially measure it, but with the rig settled down a bit, I sit at just about 12.5”

Thanks for the help everyone.

[dude26]

mount your front shock one (or two ) hole forward

[cpercival]

I was kind of wondering about that. Unless I misread it, this is how Krawlfreak has his set up. Seems really laid back to me, but I guess he should know best considering he designed the chassis. Definitely open to other suggestions though. What does standing a shock or laying it down do for you?

[Gfresh]

Originally Posted by cpercival

I was kind of wondering about that. Unless I misread it, this is how Krawlfreak has his set up. Seems really laid back to me, but I guess he should know best considering he designed the chassis. Definitely open to other suggestions though. What does standing a shock or laying it down do for you?

Laying a shock down makes the action a lot softer.
Effectively softens a spring, as the forces have a greater advantage over the spring (IMO).

I think it can change how the spring acts through out the stroke too - correct me if I am wrong please:
When the shock is more upright, it has a linear compression (roughly equal strength through out the stroke/compression.
Laid down, I think, as the shock compresses it has a slightly rising rate (i,e, gets a little stronger the more it compresses) - but bear in mind the laid down shock is a load softer than the upright one.
If its laid down lots - it can have the opposite in that as the spring is compressed, the strength of the spring get less and less.

hmm that could all be wrong mind you!

[dude26]

when you mount your shock upright it become more firm, but you can change this by the spring/oil/piston combo
I said that because Iit that your skid is low, and mounting your shock more upright change your ride height
I hope to not say stupid things