Question about a hitch extender reducing hitch capacity

Let me start off by saying that yes, I have a basic understanding of why you'd want to lighten a load if it were moved further away from a set point, but in my case, I will actually be moving the load closer but I will be using an extender.

My travel trailer has a Curt hitch installed (#13704) and I was using a Curt cargo carrier (#18153), both rated for 500 lbs (I use the hitch strictly for the cargo carrier). With that set-up the front end of the carrier is ~19 inches from the hitch pin hole but supposedly (and maybe this is where the "rub" is), that set-up is rated for 500 lbs.

I am getting a new cargo carrier/bike rack combo that has ~6 inches from the hole to the front of the carrier, and that will barely clear the trailer, so I was going to get a 6-8" extender. In the end the load will be max. ~14 inches (6" for the carrier tube and max. 8" extender) from the hitch pin hole, so 5" closer than the previous set-up, but everything I see says the extender reduces the capacity of the hitch by 50%.

Obviously if I used my original cargo carrier with an extender, that would make sense, but the new set-up will have the load CLOSER to the hitch, so I don't understand the blanket statement regarding the 50% reduction.

Or, and this is the "rub" I mentioned, is the hitch rated for 500 lbs but only for a set distance, meaning my previous set-up may actually have been OVER spec.

I never had close to 500 lbs on it, and probably won't get near 250 lbs (new carrier is only rated for 300 lbs of cargo), but I was hoping someone could explain why, or is it just a generic statement that may not actually apply in all situations?

Thanks!!

 

I have a 18" extender I haven't used yet but planning to soon keep the truck out of the saltwater as much as possible. I spoke to Reese today and they told me the same thing. 50% reduction. He never gave me a reason why and I never thought to ask.

My concern is the bolt stress holding the hitch on. The further out the more stress. Plus after reading another towing thread will the extension bring the rear down further and effect the steering.

It's only a 15 minute straight run to the ramp but something in the back of my mind. The first trip will be a little nerve racking even though it's what's the extender is designed for.

 

I am not sure I am reading / visualizing your scenario……but will take a shot. Let me know if I am way off how I am interpreting this. Have you considered welding a slightly longer receiver onto the rear bumper of the trailer? I would be very careful using something that long (18”) on the trailer……you also have to remember that they will change the geometry. They may drag going up or down grades

If this is to extend from the truck receiver to the trailer, again those stress points are much more compromised…..I wouldn’t consider using an extender like that on anything with even slightly significant weight to it

 

This is the extender I will be using. The OP may be thinking the same thing only smaller.

Reese Towpower 11004 18" Hitch Box Extension

https://www.amazon.com/gp/product/B0008FUH6E/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8

 

Wouldn’t an extended drawbar accomplish the same and still retain more towing capacity?

$51 Reese 80232 Hidden Hitch® Angle-Cut Class III Ball Mount - 16" x .75" x 2", 6000 lbs.

https://www.amazon.com/Reese-80232-...gid=pla-492434410005&ref=&adgrpid=58868508141

 

I think that the 50% reduction is a safety statement from the manufacturer for any looking to tow with it. If you are just using it for a cargo rack on the back of your trailer, you should be fine.

 

From here: http://www.visualsc.com/hitch_calc.htm


Know what you have and what you are doing. I see too much bad/incorrect information being thrown around and preached. Too many idiots on the road with no clue.

 

It's the same thing as a using a breaker bar or torque wrench, the longer the lever arm, the more moment (torque) which reduces the capacity since less force is needed to get the same moment (torque). An extender, a longer hitch, moving the receiver so it hangs out the back of the truck further, all that shit results in the same loading of the chassis and subcomponents. The actual hitch pin force won't change, so it's only in shear and not reacting the moment. I would extend the trailer tongue, which reduces your tongue weight but as far as the trailer is concerned the forces are essentially the same still.

I would be very careful using an extender with any considerable force. A hitch that sticks out 8" past the receiver is double the moment (torque) of a 4" long hitch being dumped into the receiver, which means the receiver, the receiver bolts, the chassis, the rear suspension, all that now has more stress going into it. It's a linear increase with distance, so something like an 18" long extender (or just a hitch thats 18" long like above) is now 4x more bending moment being dumped into the truck (versus a normal hitch) plus you still have the vertical loading from whatever the hitch is supporting. There's a reason you use a breaker bar to break a bolt loose, and you're now doing the same thing to your truck.

 

I'm not sure about the specifics of how the max tongue weight is defined, but I think at a basic level, if the center of mass of the load you're carrying is actually closer to where the hitch is attached to the frame you would be actually reducing the stress on the back end of your truck. The question becomes if the new extension is sufficiently strong for the task.

Maybe you were overloading it originally, but it sounds like the new setup would only improve things (assuming the new extension is comparable in strength as your first setup). Hard to say without seeing both setups and where the loads are being applied.