I recently received a question from a lady named “Cassandra” about the tongue weight on her travel trailer. Here’s what she wrote:
“I have a [Rockwood] Geo Pro 19FBS that is 14.7% DRY hitch weight. I cannot understand how it can be properly loaded and stay with 15%. The only storage behind the axle is shower, fridge and entryway. FR [Forest River] refuses to answer saying over 15% is ok. Thoughts?”
What a great question! Cassandra wants to know if she can safely load her RV and stay within an acceptable safe range. That’s responsible RVing!
Let’s answer her: Is there such a thing as too much tongue weight?
Is There Such a Thing as Too Much Tongue Weight?
If you’re new to travel trailers and towable RVs, you should know that tongue weight literally stands between you and possible death.
Most RVers first learn about the dangers of too little tongue weight and how it causes trailer sway. But Cassandra is asking whether there can be too much tongue weight.
But what should we expect “average” tongue weight to be?
The rules of thumb for towable campers is:
- For travel trailers, 10-15% tongue weight;
- For 5th wheels and goosenecks, 20-25% tongue weight*
These are “sweet spot ranges.” They may be superseded by what’s in your Owner’s Manual. Note these are percentages of Gross Trailer Weight, not the GVWR.
So is Cassandra really that close to her maximum?
(*5th wheels can have a greater tongue weight because the pin weight sits directly above the tow vehicle’s rear axle. In contrast, a travel trailer is coupled with a bumper hitch, which exerts leverage on the tow vehicle. More on this later.)
How to (Painlessly) Calculate Tongue Weight Percentage
First, let’s check her numbers – and show you how to make the same estimate!
According to the specifications for the 2023 Rockwood Geo Pro 19FBS:
- The UVW is 3,375 lbs. Rockwood notes that “The UVW does not include cargo, fresh potable water, additional optional equipment or dealer installed accessories.” I don’t know if Rockwood installs batteries at the factory, so batteries may or may not be included in the UVW.
- The tongue weight* is 479 lbs. If we divide TW/UVW*100 = 479/3375*100 = 14.2%. Cassandra said 14.7%, which is only a 17-lb difference, so we’ll assume that she’s right and the specifications sheet is slightly inaccurate!
(*You might see tongue weight referred to as “pin weight” or “hitch weight.” However, “hitch weight” is technically the weight seen by the tow vehicle hitch, which is a theoretically different concept than tongue weight, even if the numbers are often equal. So I prefer to keep the terms distinct.)
So Cassandra’s numbers check out. Straight from the factory, her single-axle travel trailer is already close to that 15% “maximum” usually cited. Oof! Now what?
Will a Manufacturer Approve Excess Tongue Weight?
Here’s my lightly edited first response to Cassandra.
Great question! First of all, over 15% isn’t necessarily dangerous with all trailers. 10% is the minimum because of towing dynamic issues; 15% is the usual “maximum” because of structural issues.
(You, like Cassandra, may have already spotted a problem with my statement. Keep reading!)
Did you check where your tanks are located? If the tanks are behind the axle, they will decrease tongue weight when full.
Rockwood probably doesn’t want to be on the legal hook for how you load your trailer. Hence why you probably won’t get black-and-white approval to increase tongue weight above 15%.
It could be that the manufacturer just didn’t do their math correctly, and you might be stuck with a trailer that has sufficient cargo capacity but not enough tongue weight capacity. I certainly hope not!
While I can’t tell you what’s safe and what isn’t, I would say that many utility trailers are capable of up to ~20% tongue weight without compromising the frame. Whether the Geopro is or isn’t, I can’t say.
Now, I neglected to mention an important point. When I said that “15% is the usual maximum because of structural issues,” I didn’t explain I was referring to the trailer itself, not the tow vehicle!
But Cassandra was smart. She spotted my oversight. So she wrote back:
I thought the 15% max was to avoid causing problems such as steering and braking with the tow vehicle?
The issue I’m dealing with is TOO MUCH tongue weight. Apparently single-axle trailers tend to be tongue-heavy.
Unfortunately, my freshwater tank is up front so I need to tow with it empty. My solution has been to 1/2 fill the black tank, which is behind the axle.
Good job, Cassandra! She knows her RVing stuff, and she points out that too heavy a tongue weight can be just as dangerous as too little.
What Happens If Tongue Weight Is Too Heavy?
First, let me explain my original comments about the ~20% rule (which I should have phrased better).
Q: Can the Trailer Handle It?
Tongue weight recommendations are not the same all over the world. Regulations for tongue weight didn’t come out of a laboratory; they are somewhat empirical.
- In the UK, for instance, tongue weight is called “nose weight” and the recommended target is about 7%.
- In Australia, maximum tow ball weight is 10% of the Aggregate Trailer Mass (roughly equivalent to our GVWR).
But in these countries, RVs are much, much smaller. Trailer wheelbases are shorter. Speed limits are lower. Braking laws are different. Design standards are different. All that potentially impacts tongue weight recommendations.
So, keeping an open mind, is there something inherently “wrong” with a 20% tongue weight on a travel trailer?
Not in all scenarios, I believe. Particularly with smaller travel trailers.
There are many smaller travel trailers – fiberglass “egg” campers, teardrops, mini travel trailers, pop-ups, etc. – where 20% is more common than you’d think. If you added a spare tire and an extra battery to a teardrop, for instance, you’ve probably increased tongue weight by 5% already!
As long as the chassis is designed to handle the extra tongue weight, then I don’t see anything inherently wrong with up to a 20% tongue weight – for smaller trailers! (less than ~3,000 lbs).
But why not medium- or large-sized travel trailers? Why can’t they have 20% tongue weight, too?
Q: Can the Tow Vehicle Handle It?
Just because the trailer can handle it doesn’t mean the tow vehicle can! As I’ve said before, the weakest link in towing breaks the chain.
Most trucks are payload-limited, not tow capacity-limited!
A trailer does not exist independent of its tow vehicle. The tow vehicle must stay in control at all times while cornering, braking, and accelerating. But the higher the tongue weight, the more lateral control a trailer has over the tow vehicle!
Let’s consider an example:
- At 10% TW, a 7,000-lb travel trailer has 700 lbs on the tow vehicle hitch. That’s a lot of weight – most pickup truck manufacturers will require a weight-distribution hitch at that kind of weight! But it’s doable. A Silverado 1500 could probably handle that.
- At 20% TW, that same travel trailer has a hitch weight of 1,400 lbs. Oof! You’ll need a beefy Class V hitch. You’ll be lucky to get away with a Silverado 2500HD!
You’ll see a similar problem with 5th wheels. Above 20-25%, the pin weight of a 5th wheel is often just too much for the RGAWR (Rear Gross Axle Weight Rating) of the tow vehicle. This forces customers to upgrade to larger trucks.
Why, just this week, I received another email from an RV owner with a 5th wheel hitch weight of up to 37%! She’d be lucky to get away with a Silverado 3500HD dually!
Q: What Happens to Steering and Braking?
Let’s go back to Cassandra. She asked, “I thought the 15% max was to avoid causing problems such as steering and braking with the tow vehicle?”
Good eye, Cassandra. Here’s what I said in response:
You’re spot on! Even if the trailer can support 20% tongue weight, the tow vehicle often can’t, and yes, it can definitely cause steering and braking problems.
It’s all relative. A pickup truck probably wouldn’t have a problem with a tiny teardrop trailer at 20% tongue weight, but it likely couldn’t handle a regular travel trailer at 20% tongue weight. That’s one reason a weight-distribution hitch is really essential with a heavy tongue.
What I was trying to say is that a larger tongue weight may be acceptable if the trailer is significantly smaller than the tow vehicle.
But if the RV is similar or heavier in weight than the tow vehicle – which is very common in the US – then an overloaded tongue becomes very dangerous!
Too much tongue weight can increase trailer sway – and make it more difficult to control.
Remember playing on a merry-go-round at the neighborhood park? Remember how when you moved from the center to the edge you had to hold on tighter?
The farther away mass is from the center of gravity, the more leverage it has. So when a trailer yaws – that is, when it rotates about its center – a heavy nose keeps that momentum going.
(Engineers call this the “polar moment of inertia.” If you’re a numbers geek, someone else already beat me to it and did a full write-up of how tongue weight impacts lateral forces. You can read the write-up on a forum at RV.net. Or you can take a sneak peek into the book Vehicle Stability.)
“If you have too much weight exerted on the hitch ball, the force could overload the rear tires of the tow vehicle and push the rear end of the vehicle around.”
Potential problems of too much tongue weight include:
- Overloaded tow vehicle rear tires
- Poor tow vehicle braking performance
- Reduced cornering traction
I don’t know what Cassandra’s tow vehicle was, so I can’t comment on whether her combination might be safe.
What’s Cassandra To Do About Her Tongue Weight Problem?
Cassandra is facing an issue common to many RVers: How you load an RV changes its tongue weight.
Imagine yourself balancing on a teeter-totter. What happens if you lean or shuffle to one side? It tips!
Same thing with RVs.
- If you load cargo in front of the axle, you’ll increase tongue weight.
- If you load cargo behind the axle, you’ll decrease tongue weight.
- The closer you load cargo towards the front, the greater percentage of the weight will be borne by the tongue.
Here are some examples:
- If you load cargo directly above the axle, you will neither increase nor decrease tongue weight. 100% of the weight will be borne by the axles.
- But if you add, say, an extra 40-lb propane tank to the tongue, then almost all of that weight (~90% or 36 lbs) will be added to the tongue weight, not the axles! The axles would only take the remaining weight (~10% or 4 lbs).
So Cassandra has a problem: Her travel trailer, straight from the factory, already has a heavy tongue weight. How can she reduce it?
What are some possible solutions?
- Judiciously fill up tanks. Cassandra is already doing this. She’s partially filling her black tank to reduce tongue weight. That’s clever, but it’s unfortunate she’s forced to do this. Water counts as cargo, so now she has to carry less cargo to stay under her GVWR. It’s wasted capacity.
- Redistribute cargo. I suggested she move her spare tire to her hitch. It’s a similar idea: Moving cargo behind the rear axle will decrease tongue weight.* Unfortunately, for most travel trailers, a significant portion of the tongue weight is the propane tanks and batteries, which cannot be easily relocated since both propane and batteries can produce dangerous gases.
- Tow with a bigger vehicle. I don’t know what her tow vehicle is, but if it’s an SUV or smaller pickup truck, she may want to trade it in. The usual recommendation when loading a trailer is to ensure 10% of the cargo is on the tongue. If I crunch some numbers … At full GVWR (4,479 lbs), Cassandra will have about 580 lbs on her hitch … and potentially as much as 700 lbs!
- Use a weight-distribution hitch. Weight-distribution hitches return some of the tongue weight to the trailer axle. Just make sure you aren’t overloading your axles!
*As I mentioned earlier, Cassandra is being forced to distribute weight to the ends of her RV, which can increase trailer sway. Not good. Creates instability.
Is the Manufacturer Responsible?
I can’t answer that question in Cassandra’s case. But here’s some guidance from NHTSA:
If a range is specified, the axles should be designed to accommodate the worst-case scenario which would be when tongue weight is at the minimum portion of its range and more weight is shifted to the axles. Consumers should load their trailers in a fashion that keeps the tongue weight within the range recommended by the manufacturer.
Note that it is the customer’s responsibility to stay within the range recommended by the manufacturer.
So What’s the Final Answer?
Unfortunately … this is a tough issue to fix aftermarket. It’s already baked into the design. The manufacturer could have shifted the axle a few inches forward to reduce tongue weight, but Cassandra can’t do that.
There is no silver bullet for Cassandra. Hopefully her trailer is small enough (and her tow vehicle big enough) that she can handle the extra tongue weight without compromising steering dynamics. If not … she might be shopping for a replacement sooner than she planned!