Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - single ladder bar for my 1950 street truck
View Single Post
  #11 (permalink)  
Old 05-22-2013, 04:26 PM
ben s. ben s. is offline
Registered User
 
Last photo:
Join Date: Mar 2010
Location: st. louis missouri
Posts: 190
Wiki Edits: 0

Thanks: 9
Thanked 10 Times in 10 Posts
Quote:
Originally Posted by astroracer View Post
Nice looking fab work, Ben. If I could make a few observations?
1.) The leaf springs are still there, right?
2.) The panhard bar is very short. The bar will push the axle back and forth, crosscar, in an arc not in agreement with the "straight" up and down travel of the leaf springs. This will put a lot of deflection (read as "bind") into the leaf spring bushings.
3.) The panhard bar is at an angle at ride height. This angle will induce more "arc travel" of the rear end into jounce then rebound. You really want the bar parallel to the ground at ride.
4.) The ladder bar front mount is farther forward, in the side view, then the leaf spring front bushings. This will also drive more bind into the leaf spring mounts as the rearend will now want to rotate around the ladder bar front mount as well as the leaf spring mounts.
I do not want to get you upset... Suspension design is what I do for a living so I notice things like this...
Mark
Mark,
Yes the leaf springs are still there. I know the bar is short and angled down somewhat. Two things: 1) the axle does move side to side. It has rubber bushings and stock shackles. It moved just as much, if not more than the panhard will move it. 2) were the bar to be level, upon compression at current bar length it would deflect the axle laterally the maximum amount possible. Presently, It starts midway through the arc, and upon compression of the springs the bar should only make it back to the opposite midpoint. Theoretically, this reduces over all axle displacement because the panhard bar arc length is reduced.
Regarding the front mount: I have a large leaf spring shackle that the bar connects to. It will move fore and aft (and yaw somewhat because there are two rubber bushings on the ends). Yes the bar and the leaf spring have disimilar arc lengths, however the shackle should compensate for this, at least that was my intention. We're it to be rigidly mounted to the frame at the front, I should think it would bind.

Now, as a suspension guy, do you still think it would matter that the arc length of the leaf spring and ladder bar are different, even though the bar is able to move front-to-back with the axle?

You won't upset me. That's why I post this stuff. I want to know what you guys think.
Reply With Quote