Those look to be mostly for show. But a ladder bar being used in conjuction with leaf springs was usually to keep the spring from wrapping and the rear end twisting. I have no faith that the ones in the pic will do that...
Jegs and Summit both sell an axle floater for just that purpose. The bars locate the rearend front to rear and the springs suspend it and locate it side to side. The floater lets the rear slide front to back on the springs while the bars physically locate it. I hope that came out right.
you would use floaters......they allow the leaf spring to hold up the body ....and allow the ladder bar to do its thing.....the plates are slotted so the leaf spring will move front to back ....as to not bind up.....check in the jegs catalog....usually in there....brandon
You can use ladder bars with sliders between the axle and spring pack or you can mount the bars solid to the axle and hang the front of the ladder on some small shackles. No rotation, no bind. There used to be a Willys gasser that ran up here that had the front of the ladder bars linked to a lever that rubber snubbered the front axle downwards, any rear axle rotation was transfered to lift in the front suspension. The bars on that truck are there for added weight....I guess that would help traction some
use a shackle on the front of a traction bar and it allows the bar to move forward and back with the arc of the leaf springs compressing, but will keep the axle from rotating
I dont have a picture, but in the summit catalog (jegs too) there are a couple leaf spring mounts that do away with your spring pearch and allow your rear end to slide on the spring, therefore not allowing the suspension to bind. Kind of like these....but there are more than one type. http://store.summitracing.com/egnsearch.asp?N=700+4294925130+4294839061+115+4294812057
You can get floating mounts that let the ladder bar handle the location of the rear and and let the leaf springs just do the suspending part. Chassis Engineering make these ones ... http://store.summitracing.com/partdetail.asp?autofilter=1&part=CEE%2D2030& Edit: Must type faster
The spring is what actually lengthens. It goes from a arc to straight in suspension movement. The spring is not a fixed locator as in a radius rod, hairpin or 4-bar, which is why it can work with ladder bars. It has the ability to change length and therefore the conflicting arcs are moot.
Two things. First, I want the guy who built those ladder bars to bring my Erector Set back! Second, there have been a lot of guys who just said 'fuck it' about suspension geometry. Most of 'em had Chevelles (and similar cars) with the coil springs and factory 4 link, but added the bolt-on ladder bars. Stopped wheel hop real good... the suspension won't hop if it can't move. -bill
Not to over simplify it, but ladder bars still let the spring and suspension work (vertically) for the most part, cause they'll pivot at the front. When you launch it hard, if the tires hook they in turn try to twist the axle housing. The ladder bars (or slapper bars to a lesser extent) hit the frame or forward spring mount, which helps keep the axle from trying to turn and wrap up the springs. Kinda. And you're right, the one's in the pic look to be all show, no go.
Origanally Ladder/traction bars were only meant to go 1320 ft at a time. I remember that they weren't street legal for a long time.
Awspence is definately correct (nice first post by the way...keep up the good work!). The shackle will allow for complete axle movement forward and backward from the arc of the spring. 4X4's have used this style offroad for years as it doesn't limit wheel travel by binding. Also many guys use one ladder bar mounted in the center along side the driveshaft for greater axle articulation. I would like to see this set-up on a hot rod or gasser that does hook up to see what effects a single ladder bar would have upon launching. Hell, I may try it on my "A". BloodyKnuckles
those look cool, but don't work. caltrac type bars are the only thing that work for me. leaf spring/4speed combo.
When I ran ladder bars on a leaf spring car - I removed the welded on spring pads and simply let the new spring pads rotate on the housing with a 360 degree mount. No more conflicting arcs.
Back in the day, our car was a race only vehicle and ran "traction bars" bolted or welded (can't remember now) to the spring pads. With our seriously underpowered flathead, we never worried about conflicting arcs and that is how pretty much everyone did it back in the '60s. That doesn't mean it was right. We just didn't want the springs to wrap up. We figured we were OK if nothing broke and it didn't. Drag race suspension technology had a very long way to go.
When using ladder bars with a leaf spring rear suspension, the axle housing cannot be rigidly attached to the springs. If it were, severe binding of the rear suspension would occur because the Ladder Bar and the leaf spring both travel in separate competing arcs. By allowing the housing to rotate and glide on the leaf spring, the Floating Housing Mount eliminates the bind and allows the Ladder Bars to work the way they were designed. Disclaimer ; all of the enclosed info was borrowed from the Competition Engineering websight .
And another thing... I would think that front and back movement of the axle would be more of a conflict than rotation. Springs are flexible and will allow rotation. However, as they work, they change the amount of arc in the spring, which moves things backwards and forwards from the fixed front spring mount. It's why you have to have shackles on one end or the other. It isn't inconceivable to me that you could put shackles on both ends of the springs and locate the rear end with ladder bars and a panhard bar or whatever. Or is this how it is done? Of course, by the time you have done all this, you could have put on coil overs. For a guy that spends as much time at a drag strip as I do, you'd think I would know more.
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