Front axle hill-climb limiting strap

[PARKINGLOT]

one more great idea from the mind of junkie!

 

[Bent Bolt]

Cool idea. Thanks.

 

[CopyKat]

Interesting idea.

 

[samsonitesamsonite]

as soon as I get some tubing, Im gonna do it.

 

[CopyKat]

But it looks soo kool!

 

[CopyKat]

Now I got to thinking. How do you keep the cable in the pulley? what happens to the slack in the cable?

Now if you were to add a nice heavy spring between the cable ends. you could use it to pull the slack but the spring will allow some slack in the cable.

Ideas are floating now.

 

[arrabil]

I was thinking that too, but it seems to me the cable has no where to go put the pulley groove when it gets tensioned.

 

[CopyKat]

So Junkie how much droop did you limit it too?

I still think it's alot of snapping and chaffing having the cable slack like that.

 

[arrabil]

So what rate spring would you use and rated for what strength? They have to hold a serious amount of "bouncing" weight. 4x4junkie said he has 3-4" slack for each wheel.

 

[kunar]

So what rate spring would you use and rated for what strength? They have to hold a serious amount of "bouncing" weight. 4x4junkie said he has 3-4" slack for each wheel.

i was thinking about this at work today, you dont want a spring inline in the cable. what you need is a pulley somewhere in the middle of the cable where it is slack that is pulled out by a spring. that way the tension from the cable never travels through the spring. anybody understand what i'm saying? it will work like an idler pulley, it has to be inline with the other pulleys though. i have also seen somewhere (magazine im sure but i dont remember where) that people had used small atv winches attached to the frame to pull on the axle, compressing the suspension. this could also be adapted to the ttb, my first thought would be by mounting the winch to one axle beam in the same spot where the cable would normally be teathered. with this setup the axle could still articulate but the length of cable could be changed...if you really want to get technical you could use one winch for each side so you could adjust them individually....

edit: if you wanted a spring inline, it would have to be similar to a screen door chain's spring, set up so after it is extended a certain distance then be mechanically limited, another idea would be putting a couple loops in the cable maybe 8" apart and putting a 4" spring between them so the spring can only stretch another 4" before the cable is taught but now im just rambling...

 

[4x4junkie]

Now I got to thinking. How do you keep the cable in the pulley? what happens to the slack in the cable?

Now if you were to add a nice heavy spring between the cable ends. you could use it to pull the slack but the spring will allow some slack in the cable.

Ideas are floating now.

The cable is completely contained within the tubing, it has no place to go but the pulley groove when it pulls tight.

The slack isn't a problem either, it's hardly different than the slack you'd have with any other limit strap, just make sure it won't get caught in or on anything (unlike a nylon strap, you can also "bend" the cable slightly so it hangs away from things like the coil spring, etc. too).

 

[xBLAKEx]

I know this is a super old thread, but I was just wondering how you would determine how long the 'limited strap' would have to be?

Thanks

-Blake

 

[4x4junkie]

Dang, I had forgotten about this thread lol :icon_twisted:

I guess the best way to set it up would be to measure the ride height of your truck, attach the cable, then jack the front up by the frame and see how far it droops before the cable gets tight and the wheels lift off the ground, then adjust it as necessary (that's basically how I've been doing it anyway).


I've had it set for about 4" droop from ride height. You can go more or less than that if you want, though you'll start feeling it hit more often when you go over bumps, crowned intersections and stuff if you set it for much less (similar feeling as when you've cranked the torsion bars up too much on an A-arm IFS vehicle).

 

[xBLAKEx]

Haha thanks for the reply! I had come across it today. It sounds like it really works? And not to sound dumb, but how do i measure the ride height? Ha

 

[dangerranger83]

I read that this could be done to a straight axle but cant quite picture exactly how to hook everything up and whatnot.

I do get the physics on what it is doing to the TTB setup and can picture in my head exactly what it is doing to it.

BTW is this setup in the tech library? If not, it would be another great thing for it or added to the TTB sticky.

 

[Bennybooster]

Theres not really a point to do it on a SFA truck, just run a center limit strap

 

[4x4junkie]

Yep, with a straight axle, the strap/cable simply attaches between the center of the axle housing and the frame above it. With TTB (IFS) the cable attaches to both ends of the axle and is run over the frame because there's no available "center" of the axle to attach it to.

As for measuring the ride height... Almost any reference will do (frame to ground, fender to ground, tire to fender, fender to hub... You're just looking for the difference from static ride height to the point the cable limits droop).

BTW is this setup in the tech library? If not, it would be another great thing for it or added to the TTB sticky.

There is a link in the Suspensions FAQ to a page containing a link to this thread, however it's not a direct link from the FAQ. I'll see what I can do.

 

[2813josh]

:icon_thumby:This is an awesome idea... glad this thread was revived so I could see it.