Would like to install either Triangulated 4 bars or ladder bars in a full rendered 34 Ford PU. Would like opinions on which is better in terms of installation, ride, and clearance issues. Am planning on buying someones kit and using coil overs, any suggestions on that. Thanks to all for your advice.
Keep in mind that the stock suspension is essentially a ladder bar setup. If you split the wishbone and move the forward pivots outward (away from the centerline of the car), that puts added stress on the connections at the rear axle. In effect, the rear axle is now operating as a sway bar. This is why ladder bars aren't known as particularly good street suspensions. A four-link addresses all of these issues while still offering very similar geometry. Basically, it's the same issues you'd have in a beam front axle vs a tube front axle setup if trying to use split bones or hairpins. The beam axle will twist (by design), the tube axle won't and the connections at the axle can fail.
Nothing wrong with ladder bars and they are more traditional than a 4 bar and as far as not being good for street suspension is off base. I used the Pete & Jake ladder bars under my 32 pickup but I also used a transverse rear spring like Henry did it. I put thousands of miles on the truck and never experienced any ill handling. HRP
Watching this tread as I'm trying to make a decision regarding these same choices only using a quick change and model A crossmember/spring
In my shop we do about 50/50 between triangulated 4 bar and ladder bars. It is a bit more of a challenge build the exhaust with ladder bars over the 4 bar. Most of the highboy chassis I build use ladder bars as they don't show from the side. Of the last 4 chassis in this instance 3 were ladder bars, 2 with QC rears and 1 triangulated. I just built a new chassis for my own 32 truck and used ladder bars. I only use ladder bars with a QC and A spring. I think ladder bars have more of a hot rod look?
A ladder bar properly set up for its intended use makes the rear suspension very rigid. A 4 link offers more articulation, so in theory rides better. I am not a fan of triangulated 4 link on a hot rod. Yes they offer ride control but throw away all the advantages of having a properly built 4 link. The whole idea of a 4 link is to be able to adjust for instant center and making a car hook up over variable track conditions. That said a triangulated 4 link a lot like the suspension under a '63 Chebby with the proper spring rate offers a very nice ride. well suited for a street rod, not so much a traditional hot rod. I guess it is a matter of ride quality verses performance. If you decide to run ladder bars I am going to suggest that for a street driven vehicle you land the front of the ladder bars on the same plane as the front U joint. You will find that you have less suspension bind and a better ride because of it. As for room under the bed the triangulated 4 link if it is built correctly will fit just fine, same with ladder bars. When you start dropping them snake's belly low is when you run into a problem.
The key to a proper and well functioning ladder bar set up (not a race car) is having them converge towards the front, per HRP's pic.
I'm going with a triangulated four link on my Model A project. The articulation mentioned earlier was the reason for me. Brookville '32 pinched for Model A chassis and Pete & Jakes four bars.
I have a triangulated 4-bar and coil-overs under my very low F1, and I like the ride and handling a lot. I copied the geometry of the factory triangulated 4-bar design from my 67 GTO because I liked the way that suspension worked. Done right, flex from axle movement occurs in the 4 poly rod-end bushings. It works good on the street, controls the axle, is quiet in operation, and needs no Panhard bar. I built mine from ASTM seamless tubing, TCI rod ends with poly bushings, and parallel 4-bar axle brackets I cut apart so the upper and lower mounts could be in their proper positions on the axle - $130 in parts. I borrowed a tap from a local rod shop to thread the ends of the bars that take the adjustable rod ends. Adjustable ends are only necessary if you want to play with the pinion angle. The rod-end bushings do take a beating if you do lots of hard cornering with wide sticky tires, but the bushings are cheap, and changing them every couple of years seems like a small price to pay for the simplicity of the design.
All it take to convert HRPs setup to competition is to make is adjustable. IE some forward brackets so that you can drop or raise the front of the ladder bar. That gives you a way to adjust your instant center. The rar where the ladder bars attaches to the rear end should already have enough adjustment to change your pinion angle when you change the front of the bars.
If you want a good handling car, go with the 4 link. If you don't know what good handling really is..... It doesn't matter And having them made with torsional compliance! Truck arms are made from channel so they can twist [which is basically what everybody is describing] If it is just cruising around, your definition of ill handling might be misleading. When it is at the limit of adhesion [ which could be slippery conditions ] a ladder bar rear suspension will violently oversteer . A true ladder bar suspension on a car that goes around corners is a time-bomb of component failure.
Exactly correct. Ladder bars turn the rear end housing into a sway bar. OK for putting around. Not so much for any spirited driving.
I have drove the crap outta that truck and done some drag racing..say what you will,this is the only way I will ever build a hot rod...4 bars are for street rods IMHO. BTW,before I built the truck I built my sedan 20 years ago,it has 4 bar suspension and coil overs,the handling in spirited driving pales compared to the suspension on my pickup..Fact! HRP
Thanks to all who have offered opinions and insights. There doesn't seem to be a consensus for one over the other. It appears people have had good results from both systems. For me personally, I am more concerned with ride and handling. Since this will be under a full fender truck, I don't think much of it will be visible so I am less concerned about a more "street roddy" appearance. One point, I am talking a triangular 4 bar, not a 4 bar with one bar on top on another. Both sides make good points, and HRP offers a good testament from experience with his truck. Again thanks to all. Decisions, Decisions.
I have a 32 roadster on the road with triangulated 4 link and a 32 coupe in the works with ladder bar setup, but this is a way from being drivable. In the construction of each I've checked the rear axle articulation through quite large travel but with nothing else attached, no spring, shocks or any other locating device(s). I found that in these tests both articulated well but whilst there was no lateral play in the traiangulated 4 link it was considerable with the ladder bars (p&j with the large urethene bushes . This however soon appeared to disappeared when the model a spring was hooked up and using substantial levers I've not managed to induce any lateral movement, but as a belt and braces solution I'm fitting a watts linkage anyway. The triangulated rear rides great on the road but I've experienced some tramp on the odd occasion it's been on the strip - but there's no adjustment (for anything other than bar length, so pinion angle adjustment really) so i'd probably put that down to poor design (mine). I'm uncertain as to whether the ladder bar will hook up well but it's not a drag car so wtf! So ultimately I'd suggest it's as much about style as anything else. But if using coilovers with ladder bars I'd say a lateral location device of choice is required for sure, but possibly not with a transverse spring - discussed to death elsewhere. Chris
I have driven both 4 bar and ladder bars, I have even driven both in the winter in KC I.E. snow knee deep to a tall Indian, ice, freezing rain and etc. I like either real well and have not experienced the problems that some of the fellas who have read a magazine and never put it to practice have.
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