Contemplating a Model A build, sbc with buggy springs and tube shocks. Looking at rear 4 bar suspension, but don't like the way the parallel 4 bars hang so low. With buggy springs, is 4 bar really needed? How 'bout traction bars with heim joints, much like split wishbones? Or, would there be binding of the linkages if buggy springs used with a triangulated 4 bar system?
You can always use the ladder bars, I used the Pete & Jack set up on my 1932 Ford pickup with a transverse rear spring, HRP
RJays speed shop is another one that has real nice ladder bar setups for the early cars https://rjays.com/rear-suspension-kits
I don't think 4 bar is necessary for a buggy spring. @Marty Strode those look really nice. I went with something similar; ladder bars and a panhard bar: This was being built knowing/accepting there'd be bind. There's so little travel, that we just did our best to make the old-style work as best as we could.
I have done a few customer requested triangulated 4 bar setups with buggy springs, seems to work good.
Brent, we plan on torturing the rear tires, so we need more substantial bars, than the over the counter parts. Your setup looks plenty husky !
I have split wishbones on a 9" Ford axle with the stock transverse spring on my '35 Ford pick up. It has held up well behind the Nailhead for 40 years.
I think the answer to your question is, yes, a triangulated 4 link can be used with a transverse spring if it's planed correctly and in an application with not a lot of suspension travel. I have such a setup in my roadster. The rear crossmember is flat and the rear spring is a '40 front spring. The top link mounts attach to the 9" centered housing at the transition of the axle tube and center swell. The spring length and the link placement are such that within normal suspension travel there is no significant binding. I did it because I wanted a low profile frame. In your case with the crossmember you have I would just use something like the P&J ladder bars and be done with it. It's a better match with the rest of your project.
Yes. That was during set up. They've been trimmed and nuts installed. Didn't want to make them too short (like the first attempt).
R Jays makes a killer set up and the best price hands down. I’m on my second set to put in my 39 this fall. Very high quality. There are pictures of them in my build thread below.
buddy sets the 4 bar up under the frame a bit... made them a little longer than most... he slides a section of wishbone over the lower bar... upper bar is out of site... profile looks like split wishbones... HIH.
I made my own 4 link set up with a '32 cross spring for my '32 5w back when they weren't readily available and I made it much higher up in the chassis so it didn't hang down. It worked fine. I had been studying the Alston drag race chassis setup book so I had a lot ideas and lots of holes to play with the IC, never did any adjusting though. The easiest way these days is to just use the P&J or Rjays ladder bars and brackets and move on. Brent, I like the double shear bracket you guys made for your Panhard bar on the rear end. Cool.
In any case, if you plan on driving on the street, your ladder bars need to come as close together as possible at the leading end. If you do not do this, you will not have suspension articulation, as you will have created a giant swingarm. Worse, when the front suspension allows body roll, the inner rear tire will lift in a corner, and you risk oversteering right into the ditch. Your outcome may vary, but probably will not be good. This is known science. Pete and Jakes sells them like that for a reason, and that reason is sound.
I built my own ladder bar rear and 4 bar front , buggy spring both ends . Some people say the 4 bar is late model , will so is the Chebbie riding the rails in most of them also . Not many 265 or 283 cubes in there is there really . The bars work fine and P&J sells tried and true Hot Rodder designed stuff .
It's good that you realize there will be bind on uneven, undulating pavement. The Pete N Jake's and other ladder bar setups design the attachment points at frame very close together and bind is all but eliminated. Those are beautiful welds on that A frame.
Damn, I'm glad to hear this, tub1. So I DO have a hotrod ! I'll never tell a single swinging d$$k about my 700R4, Vintage Air ac/heat, or seat heaters. LOL.
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