I was wondering about the length of the draw bar (piece that goes into the receiver) on a WD hitch. Is there anything "magical" about it? ie. relationship between it and the weight ratings of the spring bars, I know the "pinning" a draw bar at a different hole (some have more than one) varies / reduces the tongue weight if its further out... but what happens, if anything, to the spring bars (settings / ratings)?

Maybe the reason you have no replies is you have given no specifics on the type of WD you are using?.?. Is this a general question about WD systems, or are you asking about the specific type you employ????But as a general rule, the further out the WD assembly is from the rear axle, the more leverage the trailer will have on the TV. This is why 5th wheels are so much better at reducing sway(or eliminating it), as the pivot point is generally over the axle. The most effective, TT hitches "project" the pivot point as far forward as possible.

I think I was asking more of a general question about any relationships that people were aware of. Based on your statement about distance from the axel, it would appear that given two draw bars, the longer one will have more impact on sway BUT does that also apply to the spring bars... will they become "springier"... will you have to increase the "tension" on them or go to a higher rate spring bar to reduce any effect of the longer draw bar.... ???

A popular RV dealership in Canada actually cuts off about two inches from the shank and re-drills the pin hole to bring the hitch head as close to the vehicles rear bumper as possible. The impact of doing this is to reduce the overall length from the hitch head to the rear axle. This makes a better handling vehicle and eliminates the unnecessary leverage that the long shanks exert on the receiver. This also helps with the slack in the receiver tube. Most receiver tubes are oversized and the WD shanks tend to angle up in the receiver tube. While shortening the shank as much as possible doesn't change the amount of angle this slack creates it does shorten the shank so there isn't two more inches of shank height to overcome by the hitch set up. Thanks!Jeremiah

budwich wrote:I think I was asking more of a general question about any relationships that people were aware of. Based on your statement about distance from the axel, it would appear that given two draw bars, the longer one will have more impact on sway BUT does that also apply to the spring bars... will they become "springier"... will you have to increase the "tension" on them or go to a higher rate spring bar to reduce any effect of the longer draw bar.... ???I see now..... good question.... If I had to make an educated guess, I would say that the spring bars would have less effect on the front of the TV as the fulcrum of the spring bars to the WD knuckle haven't changed. However the fulcrum of the travel trailer tongue to the axle has grown. This would leave me to hypothesize that the wear and tear on both the WD and the hitch receiver would increase given the same net effect desired from the hitch system.But again, that would be based purely on my limited knowledge of physics.....and not real world experience.

We had a thread on this a while back.Ron Gratz, our resident engineer weighed in, and Barney the moderator contacted some hitch manufacturers. The focus was on whether the weight rating should be reduced when using a longer shank.. The consensus was that if it was a standard type WD hitch that the WD pretty much canceled out any weight reduction, and made the WD bars effectively stronger. On a hitch that imparts side loads to the receiver such as the Hensely, there would be a negative effect.... But those type hitches use special drawbars, and extended ones are not available anyways.That is all theory of course.My real worlds experience tends to bear it out.When I had my 2001 TV (same as my 2011 in sig) I went from the standard draw bar to the EQUALIZER 18" bar. I noticed that the springs did indeed appear stronger as under lightly loaded conditions the ride was bouncier. Heavily loaded, the bounce went away. With the standard drawbar, there was never any bounce. I was considering putting a little less tension on the bars to see if it would settle down. But since I tow heavy most of the time, it wasn't a big deal and I ended up getting my new truck before I got around to it.Interestingly my new truck with a much stronger suspension had a hint of front end "float" with the same hitch setup. I added one washer and it settled down. I never tried the old regular drawbar to see what the impact would be on this truck.So my opinion is that, yes a longer draw bar does make the bars effectively stronger, but whether this effect is actually noticeable will differ on different TVs.

Draw bar length, anything magical? | Good Sam Community

13 Replies

Mkos1980
Explorer
May 20, 2014
I have a regular class v drawbar with 2in drop. I cut and drilled mine so my ball is RIGHT outside of the receiver tube. I think it handles better. I dont run any wdh or sway setup and have zero issues. My hitch is rated for 1300TW and 13000 deadload and 1700 and 17000 WDH amd the drawbar is rated at 1200 TW and 12000 lbs
noteven
Explorer III
May 20, 2014
brulaz wrote:
06Fargo wrote:

...
We have towed in crosswind on snow/ice covered roads where you see all the rivets on the downwind side and none of the sidewall on the windward side at all in the mirrors.
...

Now that must have been exciting.

A touch of wind and snow on I-15 in the Idaho Falls country - winter tires, 4x4, & single rear wheels is the secret :E oh oh...
rbpru
Explorer II
May 19, 2014
My WD TT ball is quite a bit further out than my camper ball.

I figure it was the needed to allow clearance between my truck and the TT when I turn.
brulaz
Explorer
May 19, 2014
06Fargo wrote:

...
We have towed in crosswind on snow/ice covered roads where you see all the rivets on the downwind side and none of the sidewall on the windward side at all in the mirrors.
...

Now that must have been exciting.
noteven
Explorer III
May 19, 2014
We tow a 6500lbs tandem axle enclosed with our truck & camper rig, using a Supertruss and Air Safe coupler - total hitch point extension is 3ft-6in behind the receiver. What Huntindog says is true - the WD transfers weight forward more effectively with the extension.

This trailer does not "sway" - we distribute load correctly, plus it does not have much length behind the center of it's axles compared to it's length so it does not "weathervane" like a long bodied trailer with axles closer to center. We have towed in crosswind on snow/ice covered roads where you see all the rivets on the downwind side and none of the sidewall on the windward side at all in the mirrors.

The best benefit of the extension is the trailer off tracks on sharp corners like a bunk logger's trailer and nearly follows in the pickup's tracks. You can bend the unit into some very tight places if necessary.
Huntindog
Explorer
May 19, 2014
budwich wrote:
OK... so I take from this so far, that a longer draw may cause increased sway but then an "inverse" effect happens with the spring bar making them "more effective" in distributing the weight.... interesting. I guess now I am wondering if there is an "optimum"... ie. length to bar rating. Just wondering as my "new used" draw bar is longer (came with higher rated spring bars - 800lbs) than the previous 600lb unit.... probably about 2-3 inches.

Kind of related then would be why would a manufacturer offer a draw bar with multiple holes... on the shorter one, it has two. I would have thought that the longer one would be more of a candidate for multiple holes... ???
Last I looked, there was only one drawbar on the market with 2 holes (though it may be sold under different labels by now). It was a relatively light weight piece made of cast steel.
I doubt that it could with stand the higher forces of the longer hitches and the better steel that they are made of.
Huntindog
Explorer
May 19, 2014
Beachums wrote:

I see now..... good question....
If I had to make an educated guess, I would say that the spring bars would have less effect on the front of the TV as the fulcrum of the spring bars to the WD knuckle haven't changed. However the fulcrum of the travel trailer tongue to the axle has grown. This would leave me to hypothesize that the wear and tear on both the WD and the hitch receiver would increase given the same net effect desired from the hitch system.

But again, that would be based purely on my limited knowledge of physics.....and not real world experience.

There is only one fulcrum. It is not the ball. At least not in a vertical sense. The hitch bars just happen to attach to the hitch head. The fulcrum point is the rear axle of the TV.

To better explain it, lets forget about using a hitch for the momoment.

Imagine inserting a long say 4' 2"x2" bar into the TV receiver. Now lift up on the end of it.
What happens? The rear of the TV will rise and the front of the TV will drop as the pressure pivots around the rear axle, or fulcrum.
Now imagine using a 10' bar, and lifting on the end of it with the same force as before... The front of the TV will drop even more.

The same thing happens with the WD hitch. Nothing pivots on the ball in a vertical sense, as it is locked solid with the frame of both the TV and TT.
There will only be a small amount of necessary give as the bars bend when the rig encounters bumps and dips in the road.
budwich
Explorer
May 19, 2014
OK... so I take from this so far, that a longer draw may cause increased sway but then an "inverse" effect happens with the spring bar making them "more effective" in distributing the weight.... interesting. I guess now I am wondering if there is an "optimum"... ie. length to bar rating. Just wondering as my "new used" draw bar is longer (came with higher rated spring bars - 800lbs) than the previous 600lb unit.... probably about 2-3 inches.

Kind of related then would be why would a manufacturer offer a draw bar with multiple holes... on the shorter one, it has two. I would have thought that the longer one would be more of a candidate for multiple holes... ???
Huntindog
Explorer
May 19, 2014
We had a thread on this a while back.
Ron Gratz, our resident engineer weighed in, and Barney the moderator contacted some hitch manufacturers. The focus was on whether the weight rating should be reduced when using a longer shank.. The consensus was that if it was a standard type WD hitch that the WD pretty much canceled out any weight reduction, and made the WD bars effectively stronger. On a hitch that imparts side loads to the receiver such as the Hensely, there would be a negative effect.... But those type hitches use special drawbars, and extended ones are not available anyways.

That is all theory of course.

My real worlds experience tends to bear it out.
When I had my 2001 TV (same as my 2011 in sig) I went from the standard draw bar to the EQUALIZER 18" bar. I noticed that the springs did indeed appear stronger as under lightly loaded conditions the ride was bouncier. Heavily loaded, the bounce went away. With the standard drawbar, there was never any bounce. I was considering putting a little less tension on the bars to see if it would settle down. But since I tow heavy most of the time, it wasn't a big deal and I ended up getting my new truck before I got around to it.

Interestingly my new truck with a much stronger suspension had a hint of front end "float" with the same hitch setup. I added one washer and it settled down. I never tried the old regular drawbar to see what the impact would be on this truck.

So my opinion is that, yes a longer draw bar does make the bars effectively stronger, but whether this effect is actually noticeable will differ on different TVs.
Beachums
Explorer
May 19, 2014
budwich wrote:
I think I was asking more of a general question about any relationships that people were aware of. Based on your statement about distance from the axel, it would appear that given two draw bars, the longer one will have more impact on sway BUT does that also apply to the spring bars... will they become "springier"... will you have to increase the "tension" on them or go to a higher rate spring bar to reduce any effect of the longer draw bar.... ???

I see now..... good question....
If I had to make an educated guess, I would say that the spring bars would have less effect on the front of the TV as the fulcrum of the spring bars to the WD knuckle haven't changed. However the fulcrum of the travel trailer tongue to the axle has grown. This would leave me to hypothesize that the wear and tear on both the WD and the hitch receiver would increase given the same net effect desired from the hitch system.

But again, that would be based purely on my limited knowledge of physics.....and not real world experience.