Change weight by adding washer to WD hitch?

BlueOx swaypro WD hitch states in their FAQ's the spring bars should be parallel to the trailer frame:

quote:

Question: How do I know if I'm using the correct chain link when tensioning spring bars?
Answer: Choose the chain link that lifts the spring bar end and aligns the spring bar in a position parallel to the trailer tongue frame.

jerem0621 wrote:
OP...

I am a proponent of using as much head hitch tilt and the minimum number of links hanging free as possible. More hitch head angle means that your hich distributes weight easier.

In some cases, more head tilt and fewer links hanging free means the tail end of the torsion bars might be too close to the ground. I have some cargo trailers with low hitch heights, so I run the hitch head pretty much level.

Only if your hitch is configured like the one in the sketch. There are no less than three different arrangements of couplers on the frame rails, each of which will result in a different angle of the bars with respect to the frame or ground. For example, looking at Page 2 of the Reese Trunnion Bar Installation manual you quoted above, step 2 illustrates the different height off the ground where the trunnion bars should start for a rough set-up based on the coupler's mounting to the frame. If you pull it up to 5 links under tension, there's no telling where exactly it will end up as that is a function of the coupler's mounting point and, in the case of the coupler mounted to the bottom of the rails, the frame rail height.

I still fail to understand the geometry of a curved bar being parallel to anything.

And again, IF the bars end up parallel to anything, it's nothing more than a happy coincidence. It is neither a design intent nor does it affect the function of the hitch assembly in any way.

With a round bar hitch, 5 links under tension will generally result in the bars being parallel to the frame - just as it shows in the illustration.

I am done with this one
Barney

Finally had a chance to review your links from a computer...

BarneyS wrote:
I don't know what manuals you looked through but the Standard Round Bar (generic) installation manual has a picture at the bottom of p.5 that shows the minimum and states: Illustration 7, shows the correct and incorrect hook-up position of the spring bars. To allow movement when
turning, there should be at least 5 links between the lift bracket and the spring bar. The number of links should be the
same on both bars. Adjust head tilt to accomplish correct chain length..

Please indicate where in that manual it indicates that they should be parallel? Your quote specifies the number of links, but neither the text nor the sketches indicate anything to do with parallelism of the bars to anything.

Note what Eaz-Lift states on p.3 and gives illustrations.

Again, nowhere does it state that the bars should be parallel to the frame under load.. It does state,

Spring bar should be parallel with trailer frame, or a
slight angle up or down

You can't stop reading in the middle of the sentence.

In addition, the Drawtite Trunnion bar installation manual states on P.4:
There must be at least 5 links between the lift unit and the spring bar. This is necessary for proper operation of the spring bars during turns. If there are less than 5 links, the angle of the head assembly must be increased.

Again, no mention of parallelism, only number of tensioned links to allow for bar movement while turning.

The Reese Trunnion Bar installation manual states on P.3:
Raise trailer tongue and rear of car with jack. Lower yoke of snap up bracket until it is parallel with the ground, and slip the closest link over the hook (If there are less than 5 links between hook and u-bolt PLACE CLOSEST LINK ON HOOK, adjust ballmount angle rearward, and repeat
procedure).

Again, no mention of parallelism to the frame.

And finally, the Reese Round Bar installation manual states on p.3:
Lower yoke of snap up bracket until it is parallel with the ground, and slip the closest link over the hook (If there are less than 4 links between hook and u-bolt adjust ballmount angle rearward,
and repeat procedure - see Fig. 3 & 4 below).

Please read your quote more carefully: Lower the yoke of the snap-up bracket until it (they are referring to the yoke of the snap-up bracket, not the spring bar) Also, note the illustration directly below that line where it shows the bracket in the parallel position, and the spring angled down away from the frame rail as 'right'.

Lastly, I fully understand that the trunnion style bars move just like the round ones do and the only reason I mentioned the trunnion style bars was to clear up the common misconception that ALL WD bars should be parallel to the frame.
Hope this clears it up a bit.
Barney

And this is where I take issue with your statement: NONE of the spring bars for ANY hitch setup I've seen are *supposed* to be parallel to anything. If they turn out to be (more or less) parallel to the trailer frame, ground, or any other arbitrary surface, then it's just a happy coincidence and nothing more. As long as there are 5 links or more under tension, and the tongue weight is being properly redistributed, who gives a flying fig whether or not the bars are parallel to anything? Parallelism does not, in any way, shape, or form, affect their function.

Also, lets just say, for the sake of discussion, that your statement is correct. Lets say that you have your trailer set up such that the spring bars are more or less parallel to the frame rails. Then you go camping for a week, and your front-kitchen camper now has an empty fresh water tank up front, full holding tanks behind the axle, and a now-empty cooler that once contained several hundred pounds of 'brown-pops.' With the lighter tongue weight, you would agree that it may be necessary to drop on link on the chains so as to reduce the weight distribution effect on the tow vehicle, correct? Doing so would result in spring bars that are now pointed (more or less) downwards... Should the head angle then be readjusted so as to make the bars parallel again? I don't see that sort of recommendation from any of the manufacturers anywhere... Any setting with 5-links or more under tension is OK as best I can tell from the links you listed.

gijoecam wrote:
The bars move fore and aft on trunnion style hitches as well. The geometry is the same regardless of the type of spring bar used. I've looked through several of the round-bar installation manuals and don't ever recall seeing a recommendation as such. It might be a decent rule of thumb, but it's certainly not a requirement as best I can tell...

I don't know what manuals you looked through but the Standard Round Bar (generic) installation manual has a picture at the bottom of p.5 that shows the minimum and states: Illustration 7, shows the correct and incorrect hook-up position of the spring bars. To allow movement when
turning, there should be at least 5 links between the lift bracket and the spring bar. The number of links should be the
same on both bars. Adjust head tilt to accomplish correct chain length..

Note what Eaz-Lift states on p.3 and gives illustrations.


In addition, the Drawtite Trunnion bar installation manual states on P.4:
There must be at least 5 links between the lift unit and the spring bar. This is necessary for proper operation of the spring bars during turns. If there are less than 5 links, the angle of the head assembly must be increased.

The Reese Trunnion Bar installation manual states on P.3:
Raise trailer tongue and rear of car with jack. Lower yoke of snap up bracket until it is parallel with the ground, and slip the closest link over the hook (If there are less than 5 links between hook and u-bolt PLACE CLOSEST LINK ON HOOK, adjust ballmount angle rearward, and repeat
procedure).

And finally, the Reese Round Bar installation manual states on p.3:
Lower yoke of snap up bracket until it is parallel with the ground, and slip the closest link over the hook (If there are less than 4 links between hook and u-bolt adjust ballmount angle rearward,
and repeat procedure - see Fig. 3 & 4 below).

Lastly, I fully understand that the trunnion style bars move just like the round ones do and the only reason I mentioned the trunnion style bars was to clear up the common misconception that ALL WD bars should be parallel to the frame.
Hope this clears it up a bit.
Barney

The bars move fore and aft on trunnion style hitches as well. The geometry is the same regardless of the type of spring bar used. I've looked through several of the round-bar installation manuals and don't ever recall seeing a recommendation as such. It might be a decent rule of thumb, but it's certainly not a requirement as best I can tell...

The "parallel to the frame" is primarily for the round bar chain type hitches. The reason for this is that the bars move forward and backwards during turns and sharp maneuvers. This forward and backward movement can cause the bars to crash into the the frame or the chain mounts and also cause un-even movement of the chains back and forth.

This also ties in with the requirement for a minimum number of links under tension. If there are not enough (usually 5 minimum) then the chains can drag the snap-up bracket along the frame and/or cause the bar to crash into the snap-up and frame.
There needs to be enough links under tension to allow this back and forth movement. If you only have a couple of links under tension, there is no room for them to move.

That above "parallel to the frame" is for round bar hitchs only. The "Trunnion" style of hitch bar is supposed to point downwards back towards the trailer. That is the way the trunnion that fastens the bar to the hitch head is designed.

As far as telling when the bar is "parallel to the frame" goes, just use your imagination. I am quite sure you will be able to tell close enough! This is not rocket science.
Barney

N-Trouble wrote:
You add/remove washers to ensure your bars are PARALLEL to your trailer tongue when under tension. First determine how many chain links are needed to be parallel, THEN add/remove washers until tension is correct.

Why? The purpose of the spring bars is to transfer the weight. If they end up parallel to the frame on any given rig, that's just a happy coincidence, but that's not the goal. Plus, how exactly do you measure curved links as parallel to anything? That's a geometrically impossible feat!

I do understand what you are saying about only having two links under tension... Obviously at that point, the angle needs to be changed. But if I'm running at one angle with five links, why should I increase my head angle and run 6 or 7 links to achieve the same weight distribution just for the sake of making the (curved) bars (vaguely) parallel to the frame?

I would leave it right where it is and not change a thing.
Barney