Thread: Ladder Bar Q

Tweet

I'm putting Jegster Adjustable ladder bars on my hotrod. There 31.5" in length. Instructions say to mount them as far apart as possible, but also to use there ladder bar crossmember.. Being this won't be raced, I planned on fabricating my own crossmember. However, upon trying to fit everything, it seems like my chassis isn't wide enough, with the Explorer 8.8" rear end and the offet pumpkin it has.. If my chassis is 32.5" wide, where would be ideal placement for the bars inside the frame? I also see some hotrods running with ladders on the outside frame rails just like radius rods. Is that considered acceptable on a narrow frame street car?..

If you are going to build your own cross member....you can put them outside the frame rails if you have the tire clearance......the only other issue that would have to be rectified would be adding a panhard bar from the chassis to the diff to complete a triangulated 3 link set up.
Ladder bars stop the forward and rearward motion of the axle and the panhard bar stops the side to side motion.

Hope this helps

If your building for the street the ladder bars should be a close together at the front as possible, putting them on the outside of the rails will make the rear axle act as a huge anti roll bar, not good for the street, parallel bars are fine for the straight track.

Originally Posted by roadster32

If your building for the street the ladder bars should be a close together at the front as possible, putting them on the outside of the rails will make the rear axle act as a huge anti roll bar, not good for the street, parallel bars are fine for the straight track.

this is out of curiosity.....not ment in any demeaning way......
If the ladder bars are set outside the frame rails....How does it act like a huge sway bar(Roll bar)? The reason Im asking is that 1- both sides are hinged seperately(no different from a leaf spring setup), 2-you still have articulation, travel based on coil spring and shock length, 3- the only way to get that roll bar effect is to tie in both sides of the axle with a swaybar, the sway bar is attached to the frame and to the boths sides of the axle thus reducing body roll......Im having a hard time understanding how a 3 link set up acts like roll bar without the roll bar itself.?

The rear end is in a bind with ladder bars on any movement that is a roll(side to side ) and thus the whole frame acts as an anti roll device!! Putting the fronts closer together effectively takes out length/stiffness of the anti roll resistance----like late model Camaro/firebirds---one bar going up to rear of trans--

I agree with the antirollbar analogy - hadn't thought about it but that is about right.
Matt167, can we have a little more info? If it is the fleetline you are doing this on, does it have leaf springs? If so, bad ju-ju there. You will have some serious binding issues as the springs want to go straight up and down while the ladder bar travels in an arc. There are ways around this but the project becomes more and more complicated. Many on here can give you good, safe advice - just more info so's we can be confidant when we tell whats best to do.
Those long radius rods you see on the rear of an old hot rod that run up on the outside of the frame rail? Real bad ju-ju there. Don't even think about copying that setup.

You beat me to it Jerry, nice explanation.

the anti roll bar analogy would apply if there were no hind joint on the front end of the ladder bar.....which in his case his does....which allows for non binding movement

Originally Posted by jerry clayton

The rear end is in a bind with ladder bars on any movement that is a roll(side to side ) and thus the whole frame acts as an anti roll device!! Putting the fronts closer together effectively takes out length/stiffness of the anti roll resistance----like late model Camaro/firebirds---one bar going up to rear of trans--

triangulated 3 link?

Its a Heim joint and it still won't be great.

It being a Heim joint has nothing to do with it---ladder bars are in a bind in every position/loading except the confoguration that you can put a bolt thru the end (any of the 6 places) joint.

Not only that but 4 links are in bind in most locations also-- the only non binding set up is a three link and it requires an cross link to keep the rear end centered under the car

Originally Posted by RadRidesByDan

the anti roll bar analogy would apply if there were no hind joint on the front end of the ladder bar.....which in his case his does....which allows for non binding movement

The binding part isn't the front heim, it is the rigid attachment at the rear axle. The axle can go only straight up and down because there are 2 bolts attaching the ladder bar to the axle tube. If you lift one tire on a ladderbar car the suspension goes into a bind because the ladder bars are rigid on the tubes and both sides need to raise or lower equally. Imagine the rear end going from the street over a curb and into a parking lot at an angle. One rear tire will have to raise before the other, with the ladder bar attached solid to the axle tube (along with those long radius bars on a hot rod that are outside of the frame rail running forward from the rear tube) the rear end cannot rotate, it is fixed rigid, so it goes into a bind. Some thing will flex or it will break.
To avoid that situation (i think roadster32 mentioned this) you can run you ladderbars/radius rods forward and angling in twards each other so that they join up near the tranny crossmember and are kinda close together with hiems. About the same as old henry did it with the wishbone.
I get frustrated, my explanations just plain suck, hope i didn't confuse you. oj

Hey Jerry, what kind of 'confoguration' are you talking about, the normal kind or the California kind?

Originally Posted by roadster32

Its a Heim joint and it still won't be great.

thanks for the spelling lesson........
Im not gonna argue over this..... if 3 and 4 link setups bind up as bad as you say they do....they would not be the number 1 sought after suspension setup for street machines, street rods, hotrods, rat rods right up to drag racing. depending on the ladder bars design....you can install them straight out and use the panard bar from frame to diff as cross member as I mentioned in my very first post.

2 Jegs and or the manufacture of the ladder bars would not tell you to put them as far apart as possible if it were to creat an issue.

Unfortunately this fine gentleman seems to have the right answers to your suspension problem.....so I will gracefully bow out of this post.

Well, the Jegs bars are Jegster branded, Altho they could be used on the street ( and will be ), they are drag bars, and I'm 100% sure the instructions ( what little there is ), is for a Drag only setup.. As far as 3 or 4 links binding, paralel 4 links ( more commonly reffered to as 4 bar ) deffinetly will bind just about like the ladder bars... Visualize the rear of the car, one tire goes over a bump. If the ladders are perpindicular and mounted farther apart, say right inside the frame rails. the ladder will bind and push into the frame, the other ladder will pull the frame because the ladders are basically rigidly mounted in a fixed position and they both act together. The only movement they can provide is within the front heim joint, and that is up and down. The setup effectivly turns the axle into an anti roll bar. Triangulate it and it provides a bit of an arc for suspension to travel in.. Same with the paralell 4 link, they will bind in some cases side to side without an arc intergrated