Longer Shank Effects On WD Hitch

Lance provides interesting factual numbers in their slide in camper brochure regarding shank hitch extensions and the resultant weight reductions. For a 14,000/1400 tongue weight distribution hitch to extend the shank 24 inches reduces the hitch's capabilities to 8000 pounds/800 pounds tongue weight. That is a reduction of 6000 pounds/600 pounds tongue weight at 24 inches using WD. At six inches there certainly will be a reduction in hitch capacity using weight distribution albeit perhaps relatively small using the hitch and extensions Lance recommends.

Take a look at This three page thread from 2012 that discusses the very thing you asked.

In addition, a thread from 2010 goes into even more detail.

And here is another one. :)
Barney

Barney,

I wonder if folks will take the time to read and really understand those links?

Bottom line is a longer drawbar in a WDH configuration DOES NOT effect the receiver WDH rating with the caveat that for that 2 hole drawbar and I think only Reese makes that particular type 2 hole drawbar it does as I have already mentioned effect ITS CAPACITY/RATING.

I stand by my "POPPYCOCK" original post above


Larry

Thank you to everyone that replied :C

Barney, a special thank you for the links to the old threads on this topic. I read through all three from beginning to end and obtained lots of valuable info.

Larry, keep up the good work :B

It will be very interesting to see if I need to re-set the WD hitch after going from the 12" to the 18" shank like some others have suggested. BTW, I have an Equalizer hitch and I will be using the Equalizer 18" shank rated at 14K with the 12K hitch and bars.

2 many 2 wrote:
Thank you to everyone that replied :C

Barney, a special thank you for the links to the old threads on this topic. I read through all three from beginning to end and obtained lots of valuable info.

Larry, keep up the good work :B

It will be very interesting to see if I need to re-set the WD hitch after going from the 12" to the 18" shank like some others have suggested. BTW, I have an Equalizer hitch and I will be using the Equalizer 18" shank rated at 14K with the 12K hitch and bars.

Just a note I am also using a 1.2/12K Equal-i-zer WDH hitch and bars with my 18" drawbar.

This thread is a great example of how dangerous taking what one reads on the internet at face value and why one needs to do a lot of homework when searching for the actual truth.

Larry

I wouldn't use a hitch that doesn't allow my tailgate to lower fully.

The ratings of the various components DO NOT CHANGE, but their effective capacity
does when you change their geometry with a longer shank

Take any TV's receiver and it's rating listed on the label somewhere on it
NOTE that the receiver cross bar/tube/etc is a torsion bar in how it works in WD
mode.

Take a 6 foot bar shoved into the receiver pin box.

Take a 1,000 set of weights and the same weights for both of these tests....

Place that 1K of weights on the end of that 6 foot bar and measure the amount
of 'twist' the receiver cross tube has taken

Place that 1K of weights on the end of that 7 foot bar and measure the amount
of 'twist' the receiver cross tube has taken

The receiver's ratings did not, has not...changed in any way during either of
these tests....nor has the 1,000 lbs of test weights

The only difference is the length of the bar shoved into the receivers pin box

The longer bar will twist the receiver cross tube more because it has more 'lever arm'
than the shorter bar...am now wondering if anyone here has ever used
crow bars...and if have done so...used several of varying lengths on
the same hunk of concrete that they are trying to pry loose...

The length difference can be fractions of an inch...to inches...to feet...to yards

The math is the same with the constants and the variables are just in length
of that lever arm...

Could not find my old links on subject.

Can-Am RV, although I do not agree with his tow vehicles, they seem to work. But he always stresses rear axle to trailer ball rear over hang.



I found this one e.g.. this morning.

http://caravanandmotorhomebooks.com/caravan-dynamics/

http://caravanandmotorhomebooks.com/making-caravans-stable/

It would seem that the closer you can get to the rear axle with the hitch on your tow vehicle the better. But you are somewhat limited with some TV units, and you might be able to get away with it in some to most situations with a heavier TV.

The one one link that is dead now, spoke of how 1 to 2 inches closer can feel, drive and handle better. Especially in a emergency handling situation.

One subtle point which was brought up by Huntingdog in those links was how do we know that drawbar lengths including up to the longest that has been available for decades have not already been cosidered for the WC configuration in the stated max capacities on receivers. This would completely eliminate any need to provide confusing multiple numbers when using the various length drawbars even if this small addtional length if it is actually additional impacts any stated receiver capacities which IMO is still not clear.

I will just repeat again simply using a longer length drawbar for a WDH system WILL NOT EFFECT or CHANGE the stated receiver capacites such as max TW or max tow weight. Now you obviously have to use a drawbar rated for whatever load you need and this includes limiting your tongue wt. when using these 2 hole multiple TW drawbars such as the Reese mentioned in the above posts.

Finally on this multiple hole drawbar with multiple TW capacities, I could easily see where a 5/8" hole (which is the size of most hitch pins) thru a 2" drawbar could weaken the drawbar if that hole is beyond the hole that secures the drawbar into the receiver. Removing a 5/8" section in a 2" drawbar would be basically removing approx 5/16 of the mass at the point and a significant amount of the designed strength of approx 30% so derating the normal 2" strength because of that hole is logical. NOW THAT MAKES SENSE at least to me.


Larry