Teach me about trailer hitches for small RV trailers?

In My Humble Opinion
1

I’d like to try renting some variety of trailers, and eventually purchase one. In particular I’m quite taken by the smaller Scamp brand of fiberglass “egg” campers, which tend to be in the 1200 to 1600 lbs range, but no decisions yet.

I’m interested in getting a small camping trailer, and had a “Genuine Subaru” hitch receiver tube with wiring installed by the dealer on my new 2026 Subaru Forester Wilderness. The car has a 3500 lbs towing capacity and 350 lbs tongue weight capacity. The hitch receiver tube is centered 14” above the ground and takes a 2” square.

What I need help with is understanding what trailer hitch ball and ball mount to buy, so that I’m equipped to try renting some camper trailers. Within the range of small new camping trailers, is there a standard ball diameter, and ball height? And are they all wired the same way to connect to the car? Or do I need to have a variety of these to be ready for anything? Is there anything I’m missing here?

2

Balls come in several sizes, based on the weight of what you’re towing. They’re not hard to change. So get a hitch tongue that ends in a hole to which you attach balls sold separately. Then buy the ball that fits the first trailer you rent. Decent bet any other trailer in that general weight / size category will take the same size ball. At worst you might end up with two balls if the trailers you’re excited about happen to straddle the boundary between two capacities / sizes.

Hitch height isn’t that critical for towing with an SUV. Jacked up pickup trucks need a hitch tongue with a lot of drop to get the ball down to a sane altitude. That’s not you.

It’s been enough years since I’ve trailered anything that I can’t speak to current wiring and connector “standards”. There certainly are “standards”; the problem is there’s a dozen of them, each incompatible with the other 11. I’ll leave that sub-topic to folks with current experience.

3

Almost all camping trailers now use a 7-wire round (Bargman) connector. The only exceptions I’m aware of are some small pop-up campers. Google says the Scamp is no exception. If you have the flat-4 (or -5) connector on your tow vehicle, you’ll need another installation for the round connector. The flat ones don’t provide brake actuation current, so you shouldn’t use an adapter (4-wire to round) to try and bridge the difference.

Did your installation from the dealer include a brake controller on/under the dash? Or is a controller already installed as original equipment? If not, you’ll definitely need this as well.

4

For a 1600 pound trailer?

5

Note that some off road trailers have articulated rather than ball hitches, but not something you need to worry about, unless you want to do overlanding ( and I’m not sure any are for rent)
Some smaller trailers don’t even have brakes, but the heavier the trailer, the better idea trailer brakes are.
Some units have different ball sizes, and you rotate them so the correct size is pointing up.

Brian
Considering a small teardrop some day…

6

OP specifically mentioned the Scamp brand of trailer. According to their website, electric brakes are a feature on at least some of their products.

Knowing little about the OP’s specific preferences, I chose one model at random, and found Electric Brakes on the list of features.

7

Thanks! Consider me edumacated. I’ve never heard of electrically actuated brakes on a trailer that light. Even Scamp’s smallest trailer seems to have electric brakes.

8

[quote=“LSLGuy, post:2, topic:1029217”]
Hitch height isn’t that critical for towing with an SUV. Jacked up pickup trucks need a hitch tongue with a lot of drop to get the ball down to a sane altitude.[/quote]

I very rarely tow anything with my Kia Sorento - typically if I do so, it’s once a year when I’m getting the golf carts for a camping trip. The guy I rent the carts from always comments that my receiver is very low, and that he thinks I would be better off borrowing his truck instead of using my setup.

I believe this has to do with the angle of the trailer we’re attaching, and that it would put the weight forward more onto my car. I wonder if doing the opposite - something with a tongue that rises to help balance the trailer better? Or maybe I’ve completely misunderstood his concern, and should ask him next year.

9

Never mind

10

IMO, and I invite more knowledgeable people to straighten me out …

Balance & tongue weight has almost nothing to do with hitch height, at least for reasonable towing angles. Proper location of the load fore/aft on the trailer is the 99% determiner of tongue weight.

If the hitch is too low, either the safety chains or some other part of the forward trailer will drag the ground while driving. Especially over bumps or humps. That’s bad.

if the hitch is too high, the trailer’s front landing wheel may not be able to crank up high enough to get the tongue above the hitch ball. And the higher you crank that thing, the more unstable the trailer becomes. Which is worse on less than perfectly level and perfectly solid ground. You can find YouTubes of trailers tipping / turning sideways and tearing the landing wheel strut apart or clean off as the whole thing crashes to the ground. Oops! Now you’re screwed.

If the trailer carries wheeled vehicles and you’re going to load the trailer while it’s attached to the tow vehicle (IOW the smart way), then things like loading ramp length and slope get into it. If the trailer is much off level, the load will want to roll to the front or back of the trailer while you’re trying to secure it mostly centered over the trailer’s wheels. etc. Lots of potential surprises there.

In the case of an empty travel trailer, all of the load is fixed fore/eaft and hence tongue weight does depend directly on hitch angle. Lower hitch = more weight on tongue. The actual practical difference over a reasonable range of tongue heights is not large however.

But … It’s very easy to store 500 or 1000# of gear inside that 1500# empty-weight travel trailer. And where that moveable load is placed fore and aft swamps the effect of hitch angle.

11

I think this must be what I have. The outline is round, with a circle of 6 flat pins around a single round center pin. It looks like a “7-way RV Blade” for a “Camper Trailer” in an online guide I found.

It included a “TRAILER BRAKE PGTL HAR” in a ziplock bag. This has 4 pigtails and a small connector with I think 4 pins. I don’t know if they put anything under the dash, but there’s nothing new on the dash AFAIK.

I gather that 1000 lb and up trailers require brakes. My car manual says its max towing capacity is 1000 lbs if no brakes, and 3500 if brakes.

A reasonable guess! But it’s in fact their 13 foot that I’m dreaming of.

12

Note there are other Scamp like trailers – Casita is one. As far as I know Scamps have a good reputation, but I don’t know very far – I did sleep in a friend’s Scamp (at his place – a bunch of folks were staying there and I had a choice of accommodations - I picked the Scamp). I only slept there slept there so can’t comment on the bathroom or galley.

Brian

13

I believe that is the connector for an aftermarket brake controller. You still need the device which looks like this…

Note this is an example, not a recommendation of any particular model.

14

Goodness. There are details lurking around every corner.

It looks like I have to wire that into the car dashboard somehow? Does the trailer need modifying too?

Thanks!

15

Sidebar:
A mechanic friend of mine bought a boat years ago and installed a radiator and cooling system for the towing vehicle’s transmission.

16

This is a feature in the Wilderness trim package for Foresters. It’s part of why the towing capacity is higher than the other Forester trims.

17

Well, I’ll be dipped! Without going into too much detail, how is that installed?

I was also going to mention that if you got one of those hitches with the multiple different size balls, you could sneak into the KOA campground and take your pick of a test drive. :zany_face:

18

Built in at the factory, I suppose. It’s part of the car you get when you buy the Wilderness trim package version of the Forester. I bought the 2025 and 2026 versions of this car new (one was destroyed in an accident). I did hear there was a transmission cooler but never heard anything about it as an option.

It looks like there are aftermarket ones available, and they include a miniature finned radiator that is mounted just in front of the main radiator. As to how it is connected, and what circulates the oil through it, I don’t know.

19

I’d assume the trailer doesn’t need any mods, but some type of brake controller needs added to your vehicle.

I’d find a business that is dedicated mostly to hitch installations. They typically know more than the dealers (car or RV).

The job of a brake controller is to apply braking voltage to the trailer brakes, at an amount that matches how “hard” you’re trying to stop the car+trailer with the brake pedal. Once installation adjustments and settings are done, it operates automatically and you rarely need to touch it.

I think that most aftermarket controllers still rely on some type of accelerometer sensing, and you will need to set up two adjustments to get this working correctly. One of the adjustments is deceleration sensitivity, and is necessary due to the variety of mounting angles underneath the dash (some are horizontal, some slanted downward, etc.) This angle affects the way the accelerometer sensing reacts to the car’s braking effort, so there is a one-time adjustment that musts be made after installation.

It’s my understanding that most (maybe all?) factory-installed brake controllers read the amount of movement (or pressure) on the brake pedal itself. This is used to ramp up the amount of trailer braking dependent on how “hard” the driver presses the brake pedal. As such, the OEM controllers don’t need this acceleration sensor or any adjustments to such.

The other adjustment/setting common to both types is “Gain”. As you brake harder and harder, the amount applied to the trailer’s brakes will ramp up from zero to maximum braking. Gain sets the slope of this line (if that makes sense). It usually goes from 1 - 10 and the manual recommends starting at 5 and adjusting either way to get smooth braking as desired.

An experienced hitch installation company will be familiar with your vehicle, and can recommend an aftermarket installer and do all the wiring for you. IME, they can also set you up with good default settings to start out with.

I realize this advice is worth roughly what you paid for it :slight_smile: , but you probably need to consider aftermarket trailering mirrors. Your TV (Tow Vehicle) is 72 inches wide, and the Scamp trailer is 80 inches wide. This will mean your vision to the rear is a slight, but ever widening triangle behind you (using factory mirrors). The further an object is behind you, the more it will be hidden.

There are a variety of easily-installed trailering mirrors which have clasps on the bottom door-edge, and window-sill of your front doors. These can be attached in just a few minutes, and the only drawback is manual-only adjustments. As in the controller above, it’s usually a one-and-done operation. I’ve used them, and installation is under 5 minutes (once adjusted the first time) and removal in under a minute.

Here’s one type:
https://www.etrailer.com/Mirrors/Wheel-Masters/WM6500.html?feed=npn&gad_source=1&gad_campaignid=203016137&gclid=Cj0KCQjwy_fOBhC6ARIsAHKFB79BTeCcyWHoM22yrCJK9VKdIiZ4QNS-MbaSgUlFw2l0yENsftZa4SUaAjzmEALw_wcB

etrailer-dot-com is a good source for all this type of equipment. You may find aftermarket mirrors custom-fitted to your TV.

Best of luck! Let me know if I can help with any more information.