How Level Should a Tow Bar Be When Flat Towing?

If you've got a toad (vehicle that's being towed) tagging along for the ride behind your RV, it's crucial that your tow bar is as level as possible.

Why? It's because of something referred to as the "safe zone." If your tow bar is connected at too steep of an angle, this can put unwelcome strain on your suspension, tires, and vehicle frame, and in the worst cases, it can be downright dangerous. Remember, you're hauling a 2,000+ lb vehicle down the road behind a mammoth motorhome—the last thing you want is too much strain and pressure in the wrong place.

So what is the safe zone exactly, and how do you make sure your tow bar is inside it? Keep reading to discover:

How Level Should a Tow Bar Be When Flat Towing?
How to Choose the Right High-Low Adapter or Ball Mount
Can a High-Low Adapter Be Used with a Hitch Extender?
Do High-Low Adapters Reduce Weight Ratings for Flat Towing?

Watch Now: How Level Should a Tow Bar Be?

How Level Should a Tow Bar Be When Flat Towing?

When flat towing a vehicle behind your motorhome, the "safe zone" for most motorome-mounted tow bars ranges from 3" above level to 3" below level. Vehicle-mounted tow bars have less wiggle room—these should pretty much be level.

So, how do you know if your tow bar is level? (We don't recommend "eyeballing it.")

Fortunately, it's easy enough to check with a few simple measurements. Once your RV and towed vehicle are hooked up (and on level ground—don't try this on a hill), do the following:

Step 1: Measure from center of RV hitch receiver to the ground (A)
Step 2: Measure from center of tow bar base plate to the ground (B)
Step 3: Subtract the two measurements to find the difference

Step 1: Measure from ground to center of hitch opening

Step 2: Measure from ground to center point of tabs/base plates where tow bar attaches

Step 3: Subtract the two measurements to find the difference

There are three possible outcomes of these measurements:

The measurements are the same. Congrats, your tow bar is level!
The measurements are within 3" of each other. Congrats, your tow bar is in the safe zone!
The measurements have a difference of more than 3". You'll need a high-low adapter or a properly sized ball mount to bring your tow bar into the safe zone of towing. (Keep reading to find out how to choose the right adapter or ball mount!)

How to Choose the Right High-Low Adapter or Ball Mount

Knowing you have a level tow bar problem is the first step. The second is fixing the problem with the right high-low adapter or a ball mount with the correct rise or drop.

Fortunately, you've already done most of the work involved! Let's return to our previous measurements from the last section.

Once we've subtracted our hitch height and base plate heights, the difference is the distance needed to bring your tow bar level. If the RV's hitch is higher, the difference is the amount of drop you need. If the base plates/tabs are higher, the difference is the amount of rise you need. Tow bar adapters are measured from the center of the shank to the center of the receiver hole.

If you have a motorhome-mounted (hitch-style) tow bar that slides directly into your RV's hitch, select a high-low adapter with the rise/drop needed to bring your rig into the safe zone.

If you have a vehicle-mounted (coupler-style) tow bar that connects to a ball mount, you can choose either a fixed or adjustable ball mount with the rise or drop you need.

Do High-Low Adapters Reduce Weight Ratings for Flat Towing?

High-low adapters do not decrease your tongue weight rating as long as you use them to tow your vehicle.

However, when used with hitch-mounted accessories (such as a bike rack or cargo carrier), high-low adapters do reduce the hitch's capacity by 50%. Similarly, most high-low adapters cannot support the tongue weight of a trailer.

Why the discrepancy? It's due to the direct downward pressure exerted on the hitch when you use hitch-mounted accessories. A vehicle tow bar, on the other hand, exerts very little pressure because the vehicle is evenly supported over its four wheels. So at least in terms of utilizing your adapter's full weight capacity, you're actually better off towing your hefty vehicle than your bike!

Adapters may be used when towing a trailer or hauling hitch-mounted accessories provided the reduced weight capacity is still sufficient to support the item being carried. However, there are better options for these tasks. An adjustable ball mount or a fixed mount with the proper rise or drop are recommended over high-low adapters.

Can a High-Low Adapter Be Used with a Hitch Extender?

Using a hitch extender with a high-low adapter is not recommended.

Although your vehicle won't exert much pressure on the extender, most towing products are not designed to withstand the excessive torque that would result from such a non-standard setup. Most high-low adapters provide at least some extension, so it's possible that with such an adapter, you won't even need to extend your hitch farther.

If you absolutely need more extension than provided by a high-low adapter, your best option is using a coupler-mounted tow bar and a ball mount with a long shank.

Still have questions?

Give our experts a call at 800-298-8924, or contact us online. We're happy to assist any way we can!

About the Author

As a content writer for etrailer, I might spend my morning loading and unloading a bike on five different bike racks to figure out which is easiest to use. I might be in the parking lot, taking pictures of an impressive RV battery setup our techs came across in the shop and discussing the benefits of the setup with the owner. I might spend an afternoon in a manufacturer training classes for some hands-on experience with new products, and then sit down to assemble all this information into a coherent article.

At etrailer, one of our core values is that we are always learning, and I learn something new every day. I start each morning with the goal in mind of taking all of this information and figuring out the best way to answer the questions people ask us (and the ones they don’t know to ask yet), and helping people get the solutions they need to make their lives easier, safer, and more fun. I’m a DIYer at heart, so it brings me great joy to help a fellow DIYer find what they’re looking for, whether that’s a product, an answer, or a community.

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Written by: Amber S.

Updated by: Rachel S.

Updated on: 2/22/23

Robert

6/21/2023

Blue Ox 4330 tow bar specifies 7” rise from tow bar pin at base plate to middle of the receiver hitch ball. That contradicts the “flat” specification in your article. Look at your diagram and the Blue Ox diagram from their instructions manual. Don’t quibble the “flat coupler” and flat tow bar mount are significantly different. Your info needs to be changed, it could lead to a stress failure of components of the towing system. Just FYI and trying to keep it safe out there.

Chris R.

7/5/2023

@Robert I'm not quite sure what you're referring to. We don't call out a specific tow bar in this article, but simply a general way to ensure your setup gets into that "Safe Zone" when it comes to leveling everything out.

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