2500HD Tongue Weight Differences

[Cowpie]

Just curious if someone has a real clue as to why the 2500HD standard bed has a max 1500 lb tongue weight on the hitch, but the 2500HD long bed has max 2000 lb tongue weight on the hitch?  Other than maybe a different hitch, what if any does 1.5 ft of truck bed have to do with tongue weight on the same 6.0L 2500HD?

 

 

[cire0309]

Makes sense because it's a longer fulcrum. Gotta love science.

[aseibel]

22 minutes ago, cire0309 said:

Makes sense because it's a longer fulcrum. Gotta love science.

*longer lever arm, the axle is the fulcrum.

[newdude]

Long box hitch part# is different than short box, as to why, I cant say. 

[cire0309]

53 minutes ago, aseibel said:

*longer lever arm, the axle is the fulcrum.

Yes, that is true, but also more confusing to explain. It's mental image painting by numbers

 

[runsdeep]

Fat kid verses a skinny kid on a teeter totter, it's all science & leverage.

[sdeeter19555]

That leverage idea falls apart when taking in consideration a long bed standard cab versus a standard bed crew cab...

I'm pretty sure my hitch is marked 1800/18000 weight carrying...

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[Cowpie]

34 minutes ago, sdeeter19555 said:

That leverage idea falls apart when taking in consideration a long bed standard cab versus a standard bed crew cab...

I'm pretty sure my hitch is marked 1800/18000 weight carrying...

Sent from my SAMSUNG-SM-G900A using Tapatalk
 

 

Yeah, it seems kinda goofy.  A double cab with a 6.5 bed is going to have roughly same wheel base as a standard cab with a 8' bed.  So the arguments about leverage seem to fall apart especially since GM doesn't differentiate cabs in their chart.  Only box size.  It has to be something in regard to the hitch itself. 

 

And a double cab with a 6.5 bed will have less distance between rear axle and hitch than the standard cab with long bed, so the fulcrum point is more advantageous to using higher tongue weight with the 6.5 bed with a double or crew cab on that basis alone.  The fulcrum point is closer to the load.  I did pay attention in science and math classes in college when I wasn't checking out the girls.

 

But thanks for the input on it, guys.  Made me dust off my brain and think about it better.   It has to  be the hitch itself.  haven't looked up part numbers to confirm.  Either way, I am not satisfied with the stock hitch on my 2500HD DC 6.5.  I am probably going to replace it with a Curt 2700/20,000 hitch.  Primarily for the added structural support when using the dump trailer in off road conditions and better chain hook loops.  Somebody at GM was smoking something illegal when they came up with those goofy securement loops.  

[2017HD]

The fulcrum theory is a good one - so I went and looked up the axle to bumper distance - for the 6'6" bed it is 43" for the 8' bed it is 48" so that blows that theory out of the water as the longer distance applies more force to the axle.

 

The hitch PN being different would make more since. Or it is just another number they pulled out of the air.