While there are many Fun Finders being towed successfully and safely by owners with large tow vehicles without weight distribution and/or sway equipment (like me), there are a number of owners (and potential purchasers) who do (will) need one or the other or both.
Weight Distribution (WD)
There are only two situations where I see WD as essential:
1. If the tow vehicle’s RGAWR (Rear Gross Axle Weight Rating) will be exceeded after hitching up.
2. If the tow vehicle has a squat (rear sag) after hitching up.
The danger in exceeding RGAWR concerns premature mechanical wear and/or failure (rear axle, suspension, brakes, etc). This obviously can become a safety issue.
A squat is definitely and primarily a safety issue. With the tow vehicle’s nose pointed upward, even slightly, this throws headlight aim off, can introduce handling or maneuvering abnormalities (i.e., straight line tracking or steering control), and in the case of front wheel drive tow vehicles, can decrease traction and control during acceleration and stopping. While one way to eliminate squat is to add air bags, stiffer shocks, and/or additional rear leaf springs to the tow vehicle, this is only a viable solution if the RGAWR is still not exceeded when hitched up.
The principle of WD involves using leverage to remove weight from the tow vehicle’s rear axle. By having a pair of WD bars (or a single bar) extend from the tow vehicle’s hitch receiver beyond the hitch ball and back so they are below the trailer tongue, you can connect these WD bars (or bar) to the tongue via adjustable chains or shafts. It is at this connection where leverage can be applied. Shortening the length of the connecting chains or shafts causes the end of the WD bars to come closer to the tongue. This action begins to remove the entire weight bearing load from the hitch ball, which is causing the rear axle to bear all of the tongue weight. The load begins to be redistributed across the entire tow vehicle frame. The tow vehicle’s front axle begins feeling the force (picking up the weight load) that was being carried solely by the rear axle.
By using this leverage to the extreme, in other words, bringing the end of the WD bars up to the trailer tongue, one can in fact remove all of the weight bearing load from the rear axle of the tow vehicle. I remember seeing an old television commercial where this was actually done. A front-wheel drive Chevy Citation was hitched to a trailer using a WD setup. The Citation was driving around with its rear axle and tires removed. When the rig made a turn, the effective wheelbase became immediately evident. Imagine the turning radius needed for a 40 foot wheelbase!
If WD is needed (or desired), the two systems I would consider using are the Equal-i-zer or the Reese Mini 350. These two brands are designed to work with light tongue weights. Nearly all other popular WD systems require minimum tongue weights of 350-400 pounds in order to be effective.
A couple of years ago, I talked to an engineer at Equal-i-zer who admitted that the 200 pound tongue weight minimum they advertised was really a stretch. He said the Equal-i-zer really didn’t start to work until around 250 pounds and really needed 300 pounds of tongue weight to actually be effective. While I had initial concerns about the Equal-i-zer in terms of the potential harm in might cause because of the load stressors that it could impose on the Leland frame, I have seen enough posts on our two Fun Finder Boards over the last couple of years from Fun Finder owners using the Equal-i-zer who haven’t reported any such issues to be satisfied that the frame is not being affected by those stressors.
Like the Equal-i-zer, the Reese Mini 350 has been around for years and enjoys a solid reputation and loyal following. Its only disadvantage is that it doesn’t have the built-in sway control that the Equal-i-zer does.
Sway Control
I believe sway control equipment should be the last measure in fighting sway. Unfortunately, most folks use it as the first measure without addressing the other factors first:
1. Trailer tongue weight (THE most important factor)
2. Trailer tire load rating
3. Trailer tire psi
4. Trailer tire spin balance
5. Trailer axle alignment
6. Tow Vehicle size/weight
7. Tow Vehicle wheelbase
8. Tow Vehicle rear overhang (distance from rear axle to hitch ball)
9. Tow Vehicle tire load rating/sidewall stiffness
10. Tow Vehicle tire psi
(Note: the above list is not comprehensive, just the most noted)
For trailers like the Fun Finders, the Hensley Arrow is obviously not going to be used, so I’ll focus on the remaining two options: friction and cam.
A single friction sway bar is the most popular sway control device for Fun Finder owners. It is the least expensive way to moderate sway and in most cases, is all that may be needed. The disadvantage to the single friction sway bar is that it needs to be released to accommodate turning while backing. My brother-in-law tows a large popup with a single friction sway bar and he has to release the tension every time he wants to turn the trailer while backing.
The next step up is the addition of a second friction sway bar, effectively doubling the sway moderation counter-force. This is the same principle the Equal-i-zer uses. Of course the Equal-i-zer has the advantage of incorporating WD into its design. For some reason, Ford Explorer owners have reported more intense sway problems when towing the Fun Finder than other tow vehicles (see my “What’s Up with Fun Finder Sway?”). The Equal-i-zer is reported to work well in these situations.
Adjusting the tension on a friction sway bar or on the Equal-i-zer bar is the way to increase or decrease the amount of resistance you want to apply to the sway force that is exerted by the trailer.
The Reese Dual Cam uses a different method from friction. The cams are held in position until a force threshold is exceeded. In other words, the cams are locked in place until a certain pound-force is exerted, at which point the cams release and the entire setup is allowed to move freely, without any hindrance. This is to accommodate turning where the tow vehicle breaks the force threshold as it starts the turn, releasing the cams, which allow the trailer to freely follow the tow vehicle through the turn naturally. Once the turn is completed, the cams line back up in center and because no force is being exerted, they lock back into place. Out on the highway, heading straight down the road, it is not the tow vehicle initiating a turn, but rather the trailer trying to get out of line, because of sway. In this situation, there is less pound-force occurring than in a turn initiated by the tow vehicle, so the cams stay locked in place preventing sway from starting to occur in the first place. This is the advantage of cam over friction, especially with long and heavy trailers.
To describe an analogy of the difference between friction and cam, imagine you have to push a large, heavy cardboard box across the living room floor, which is carpeted. Because of friction, you have to begin to apply force to get the box to start sliding across the floor. There is a point at which your force actually gets the box moving. If you gradually apply more force, the box picks up speed and you slide it faster across the floor. Apply less force and the box slows down and can even stop if you fall below the threshold where the friction resistance is greater than the force you are applying. If you push against the box with a force below this threshold, the box doesn’t move. Apply more force and you can get the box moving again.
Now imagine that the box is in cam mode. Pushing at the same force you used to get the box moving in friction mode doesn’t budge the box. Pushing a little harder doesn’t either. Finally, pushing really hard you cross the cam threshold and the box begins moving across the floor effortlessly, as if was on wheels or on ice. It takes almost no force at all to keep the box moving across the carpet. However, stop pushing and the box stops where it is at and doesn’t budge. You have to then again apply enough force to exceed the cam threshold to get it moving again.
In a nutshell, the friction principle utilizes sway resistance, while the cam principle utilizes sway prevention.
I hope this info is helpful. Again, these are just my views.