That looks great. I wouldn't even use the rock fangs though. It'll be way easier (and safer) to just throw a soft shackle around the middle of the tube bumper and with how well you braced it you will never have an issue.
What was the belly height on your TJ?
Remember the time you didn’t want to mess with the wheel tubs to move your seat back but you decided to do it anyways? This is just like that. Remember, no ragrets! 🤣
I used this truss on my front axle for the same reason. I didn't have a lot of room. Yes, you do lose a little separation, but if you don't want to modify the floor in the back. This truss my not be what you're after because it's designed for a front axle. However, you get the idea.So I don't have much uptravel between the top of the rear pumpkin and the floor of the tub... I was going to run a truss and put my joints on top, but I don't think I will have more than 3" up travel if I do that. I'd be riding around on the bump stops at that point.
I might build a more custom truss that is flatter and run my control arms on the side of the pumpkin, rather than on top? It reduces the amount of separation and triangulation, which I don't like. I really don't want to cut the floor and raise it by a few inches to make it work.
This pic is set at the same ride height as the previous pics.-
View attachment 133724
Open to ideas....
I used this truss on my front axle for the same reason. I didn't have a lot of room. Yes, you do lose a little separation, but if you don't want to modify the floor in the back. This truss my not be what you're after because it's designed for a front axle. However, you get the idea.
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I know link separation is often said to be 25% of tire height as minimum, but I haven't read the why? I supposed the joint type can make the difference here, as rubber joints will allow more torsional flex/compression than heims, but why? What bad characteristic is induced if you only have 20% link separation? Radius arms or even a "one-link" don't have that much separation.
I wouldn’t be afraid of running your uppers off the side of the pumpkin. But don’t be afraid to think outside the box either. Like triangulate your lower links and run straight uppers outside the frame rail. As long as you have separation adjustability at one end of the link, you’ll be able to tune your anti squat to what you want...as long as it isn’t super far out to begin with.
Top shelf work Greg. Everything is coming together very nicely. 👍
Mike
You have that backward a bit in the first paragraph. Your instant center IS where your upper and lower links converge. If you have lots of convergence at the frame (like the old Factory Tubular/Outer Limit buggies always were), your instant center is essentially where the links mounted to the frame. WAY too far rearward, so they'd jack and hop. Separate the frame side a bunch, and they'd calm down a lot. When the uppers and lowers are more parallel (when viewed from the side) you'll get a lot more "neutral" handling throughout the range of travel. My super-specific recommendation would be to aim for "a little" anti-squat.I'm sure it all has to do with leverage at the axle and fighting axle wrap, making the rear suspension work properly. You want your rear links to converge at the instant center, which should be below the center of gravity. By reducing the separation at the rear axle, you're messing with those important factors.
I sat under the Willys for about 30 min last night with the rear axle in place, running thru different link placements. I really need to get the engine/trans/t-case in, if I'm not going to run a traditional triangulated 4 link with the rear uppers on the frame. It's hard to see where the t-case will sit and if I can run a cross-member under it for link mounts. There are a lot of options right now, but I don't have to stress about it yet... I still have plenty of work to do before I get there! But gathering up the rest of the drivetrain is becoming pretty important.
Appreciate that Mike! Not bad for a guy that is figuring it out as he goes! It's not perfect, but it's good enought for what it is.
Appreciate that Mike! Not bad for a guy that is figuring it out as he goes! It's not perfect, but it's good enought for what it is.
You have that backward a bit in the first paragraph. Your instant center IS where your upper and lower links converge. If you have lots of convergence at the frame (like the old Factory Tubular/Outer Limit buggies always were), your instant center is essentially where the links mounted to the frame. WAY too far rearward, so they'd jack and hop. Separate the frame side a bunch, and they'd calm down a lot. When the uppers and lowers are more parallel (when viewed from the side) you'll get a lot more "neutral" handling throughout the range of travel. My super-specific recommendation would be to aim for "a little" anti-squat.
@RockMonkey's old YJ only had about 6" of link separation at the rear axle, and it worked fine. My first buggy didn't have much more than that, since I mounted the lower links above the axle tube.
I'm not saying more separation isn't a good thing, but it's not a deal-killer. It just increases the forces on the links/joints/bracketry with less.
I knew I was on to something there! 😁Good insight about separation at the axle!