Show us your tow rigs!

[JDub]

He had a Ford F350 Then a Dodge 3500. Used a Kenworth for a couple trips. He ended up selling it and building a lake house after the Asian carp took over the river.

 

[Dennis P]

Pulls like a Dream and plenty of room for the Family and Cargo. All prepped and fresh for the new season and coming out end September.

 

[I_squared_r]

Gotta agree. With due respect...that's a sketchy setup.
That standup has to be at least 500lbs. alone. There goes your tongue weight.

Stand up is 300lbs. Maybe I’m border line over the 550lb rating, but I can move the boat back a few inches. This is a common set up on the jet ski forums.

 

[penziol]

F-150 and 242 Limited S.

 

[2kwik4u]

Stand up is 300lbs. Maybe I’m border line over the 550lb rating, but I can move the boat back a few inches. This is a common set up on the jet ski forums.

Doesn't make it a good one, just a popular one. Kinda like elections, popular does not equal qualified.

Not sure why everyone keeps accepting "because everyone else does it, it must be a good idea" when the risk to persons and property is this high?

 

[I_squared_r]

Doesn't make it a good one, just a popular one. Kinda like elections, popular does not equal qualified.

Not sure why everyone keeps accepting "because everyone else does it, it must be a good idea" when the risk to persons and property is this high?

You're taking the wrong perspective of my previous post. I see it this way: "Because many people have done it, the set up has been extensively tested." I'm going to break down my logic.

Let's ignore the idea that there is a jet ski on the hitch and examine the physics of it. Increasing the tongue length will result in a higher moment (M=F*D) on the receiver. Maybe i'm increasing by a factor of 4 because the distance is increased approximately 4x. There isn't a specified rating at how much moment a receiver can take, but I have friends that are 30+ years professional welders/fabricators that wouldn't hesitate to do this.

Let's consider the tongue weight of the trailer. Nothing has changed because the trailer doesn't care what's pulling it. Shorelander recommends a 6% tongue weight. My google search shows the AR192 weighs 3000 fully loaded on the trailer. 3000lbs*.06=180lbs. No problem, maybe that is what it is now.

So going back to the truck's tongue weight rating. I load the AR192 and adjust it according to the 6% shorelander rule. It weighs 180lbs. Then I attach the hauler (it's surprisingly light - 20lbs?) and the jet ski 300lbs. 300+20+180=500lbs. I'm borderline at my truck's rating, but the ratings are usually conservative and I feel confident.

The final factor is the load on the vehicle's suspension. The rear is sagging a little bit once it's fully loaded, people, and gear. Definitely don't want the rear of the vehicle squatting because that has adverse impact on the handling. I will install air bags to pump it up a little.

Maybe not everyone agrees with me, but I have thought about the physics of everything. I was an auto mechanic, welder, fabricator, engineer, and I have a background in many different powersports. If you don't agree with my logic, please counter my logic.

 

[swatski]

You're taking the wrong perspective of my previous post. I see it this way: "Because many people have done it, the set up has been extensively tested." I'm going to break down my logic.

Let's ignore the idea that there is a jet ski on the hitch and examine the physics of it. Increasing the tongue length will result in a higher moment (M=F*D) on the receiver. Maybe i'm increasing by a factor of 4 because the distance is increased approximately 4x. There isn't a specified rating at how much moment a receiver can take, but I have friends that are 30+ years professional welders/fabricators that wouldn't hesitate to do this.

Let's consider the tongue weight of the trailer. Nothing has changed because the trailer doesn't care what's pulling it. Shorelander recommends a 6% tongue weight. My google search shows the AR192 weighs 3000 fully loaded on the trailer. 3000lbs*.06=180lbs. No problem, maybe that is what it is now.

So going back to the truck's tongue weight rating. I load the AR192 and adjust it according to the 6% shorelander rule. It weighs 180lbs. Then I attach the hauler (it's surprisingly light - 20lbs?) and the jet ski 300lbs. 300+20+180=500lbs. I'm borderline at my truck's rating, but the ratings are usually conservative and I feel confident.

The final factor is the load on the vehicle's suspension. The rear is sagging a little bit once it's fully loaded, people, and gear. Definitely don't want the rear of the vehicle squatting because that has adverse impact on the handling. I will install air bags to pump it up a little.

Maybe not everyone agrees with me, but I have thought about the physics of everything. I was an auto mechanic, welder, fabricator, engineer, and I have a background in many different powersports. If you don't agree with my logic, please counter my logic.

I think the way you think about it makes a lot of sense, for example using “moment of force” rather than static weight is probably more appropriate to consider dynamic loads on the receiver while trailering.

That’s said you are far from being within legal limits with that setup, make no mistake about it.

For one, increasing the receiver length 4-fold does not automatically imply momentum goes up the same way, it could be exponential, not to mention also need to consider sway forces - that long receiver can jackknife your car and trailer before you know it.

Bottom line, you are exposing yourself to legal challenges that you are not likely to win if something bad were to happen. We all hope and pray nothing bad will happen to us but once in a while we’re glad if we have the insurance and happen to operate within legal limits. That’s all.

—

 

[I_squared_r]

I think the way you think about it makes a lot of sense, for example using “moment of force” rather than static weight is probably more appropriate to consider dynamic loads on the receiver while trailering.

That’s said you are far from being within legal limits with that setup, make no mistake about it.

For one, increasing the receiver length 4-fold does not automatically imply momentum goes up the same way, it could be exponential, not to mention also need to consider sway forces - that long receiver can jackknife your car and trailer before you know it.

Bottom line, you are exposing yourself to legal challenges that you are not likely to win if something bad were to happen. We all hope and pray nothing bad will happen to us but once in a while we’re glad if we have the insurance and happen to operate within legal limits. That’s all.

—

It won't be an exponential increase because the formula is M=F*D, so the force is directly proportional to the distance. There could be legal challenges, but I will only do this set up a few times and won't go on highways with it. I live about 15 minutes from the ramp and it's all stop-and-go driving. Also, it's likely that the boat will be parked 2 minutes from the ramp. If I build enough confidence, maybe I will try the set up and bring it to Lake George (4 hour drive). I guess this was an important point that I should bring up in previous replies. I was just excited to defend myself because I over think and over engineer everything.

 

[swatski]

It won't be an exponential increase because the formula is M=F*D, so the force is directly proportional to the distance.

Well, not to argue... But... it will be exponential.
Because at highway speeds you generate turbulence and aerodynamic drag force which is proportional to the square of velocity...
And it’s a real force, too, no bs.
Sorry, I had to.

—

 

[MrSelfdizstruct75]

Try again.

Oh hey another Okie.

 

[I_squared_r]

Well, not to argue... But... it will be exponential.
Because at highway speeds you generate turbulence and aerodynamic drag force which is proportional to the square of velocity...
And it’s a real force, too, no bs.
Sorry, I had to.

—

I think you are confusing D (aerodynamic drag), with d (distance).

Moment=Force x Distance

Drag = coefficient x ((density x velocity squared)/2) x reference area
In which the drag shouldn't change before and after the added jet ski. Everything in the above formula stays constant.

 

[MrSelfdizstruct75]

 

[I_squared_r]

Apparently there's a difference between an extra long ball mount and a hitch extension?

Effect on Hitch Tongue Weight Capacity from Use of Hitch Extension | etrailer.com

Plus this: How to Figure Weight Capacity When Using a Hitch Extender or Extra Long Ball Mount | etrailer.com

"One thing to note when using a hitch extender like the Hidden Hitch, # 80307, is that the the tongue weight and towing capacity of your trailer hitch will be reduced by 50 percent due to the increased leverage that is placed on your trailer hitch from your trailer."
That's with an 8" extension.

Try this: Extended Hitch Calc

Roll those dice brother...hope nobody gets hurt.

Thank you for the extended hitch calcs. From the page:

• Receivers are rated using a standard ball mount length (approximately 11 inches)
• The torque increases proportionally with the length of the extension.
• An increase in extension length results in a REDUCTION in capacity
• Exceeding the reduced capacity limits can result in bending the extension, failure of the receiver mounts due to increased torque and may cause the trailer to be disconnected from the truck causing a significant risk to yourself, your family and the general public.

What they are concerned about is the extra torque on the receiver and failure of items discussed in bullet point 3. Bullet point 3 is impossible with my vehicle. The receiver is built into the frame of the truck and there aren't bolts to fail. Also, the extension is extremely thick piece of over-engineering steel.

I'm towing this around the block. Nobody is getting hurt. Please keep your snide remark and let's have academic discussion.

 

[swatski]

I think you are confusing D (aerodynamic drag), with d (distance).

Moment=Force x Distance

Drag = coefficient x ((density x velocity squared)/2) x reference area
In which the drag shouldn't change before and after the added jet ski. Everything in the above formula stays constant.

No.
Drag is concerned with the boat, at highway speeds the boat will generate a lot of drag which in some instances be enough to sway the rear of the truck (especially if pushing the ball at a long lever of an extended trailer hitch).

--

 

[swatski]

Please keep your snide remark and let's have academic discussion.

Help me understand... By your own calculations, given the shortest extender available (8") halves the tongue ratings, you could not legally tow the combo, right?

So going back to the truck's tongue weight rating. I load the AR192 and adjust it according to the 6% shorelander rule. It weighs 180lbs. Then I attach the hauler (it's surprisingly light - 20lbs?) and the jet ski 300lbs. 300+20+180=500lbs. I'm borderline at my truck's rating, but the ratings are usually conservative and I feel confident.

Effect on Hitch Tongue Weight Capacity from Use of Hitch Extension | etrailer.com
How to Figure Weight Capacity When Using a Hitch Extender or Extra Long Ball Mount | etrailer.com
(These links provide useful but somewhat inacurate information - from a retailer persepective - they try to encourage people to tow things; a truck manufacturer or insurance company guidelines are many times more restrictive)

Not to mention your extender is longer than 8", and not to mention the truck tow ratings require the use of a WDH device.
One can argue about the practicality of the use of WDH in a boat trailer but not its legal meaning - when you are maxed out.

In addition, I can assure you that while Shoreland'r indeed recommends 6% tongue weight with their boat trailers, those trailers a never actually set that way up from the factory. Typical Yamaha jetboat on a trailer will put 2-3 fold the recommended 6% OTD - coming out of a dealer lot.

There have been discussions here about ways to alleviate the innate Shorlander/Yamaha tongue weight issues and members have been sharing a trailer tongue scale. If you get on the list, or use a hwy weighing station scales, you may be surprised by the actual weight of the boat/trailer and the tongue.

--

 

[2kwik4u]

OK, academic discussion it is.

Lets define some numbers:
We'll assume lbf = lbm for this discussion since we're on Earth (at least most of us are)

AR190 Tongue weight = 325lbf (What I measured on mine with a scale)
Stand Up Ski Dry Weight Weight = 306lbf (What the website reads)
Width of bumper = 8in (guess, might be plus or minus a little)
Distance to the hitch connection on vehicle from CG of Ski (1/2 of width ski+ bumper) = 13.4in + 8in = 22.4in
Distance to hitch connection on vehicle from ball (2x bumper + width of ski) = 16in + 22.8in = 38.8in
Distance from Hitch Mount to ball in "normal" setup (2x bumper) = 16in

This is all assuming a "static" or non-moving state. Once we get moving, we have to dynamically account for additional forces (such as braking, turning, and bouncing). Those forces are F=MA driven (force = mass times acceleration) and can get significantly large quickly when bouncing or any other such resonance appears.

OK, so in a "normal" configuration the moment supported by the hitch attachment is 16*325 = 5,200in-lbs
In the "abnormal" configuration with the Ski attached we have (38.8*325)+(360*22.4) = 20,674in-lbs (~4x the original number)

NOW.....Lets say the engineer designed this with a 7.2 safety factor. Which is what I came up with for a welded connection with uncertain loading and high impact probability. That means the engineer designed that connection to handle 7.2 * 5,200 = 37,440 in-lbs. With the "revised" loading scheme of 20,674 in-lbs, you are now at a safety factor of 1.8.........Will it break, probably not........I'll tell you though NASA doesn't even use that low of a safety factor on the majority of it's hardware (some non-life safety related items can have factors as low as 1.2 if I remember right).

So, there is the academic approach to how you can tell if you're overloading your hitch or not. I'm not driving my vehicle anywhere near that low of a safety factor.

Another interesting tid-bit to toss in here. This is EXACTLY why WDH setups are required over a certain tongue or total weight. The loading on the connection to the tow vehicle can increase quickly with shock and vibrations. You are adding safety factor by introducing an opposing moment into the equation centered on the ball. Again, others here have gotten away without a WDH, however I think it's pretty clear to see how you can quickly reduce the safety factor to beyond the capability of the hitch.

If anyone wants a more in-depth explanation of the mathematics above, let me know. I'm running out of time to type at the moment, but don't want to recreate this again later.

 

[I_squared_r]

I just set up a free body diagram and there are 3 forces acting on the receiver. Force in the y (Fy), force in the x (Fx), and the moment on the receiver (M).

Fx = 0 because there are no horizontal forces at static.
Fy = the sum of all loads on the receiver
M = the sum of all M, Force x Distance on the receiver

Jet Ski (J) = 306lb
Boat (B) = ? Depends on trailer loading

My load with the jet ski and boat.
The boards on the jet ski are 11" apart and therefore is 306/2=153lb on each board
I'm going to load my trailer to achieve 6% tongue weight for single axle trailer as determined by multiple sources online.
3000lb*.06=180lb
Sum of the forces = 153+153+180 = 486lb

Distances from the receiver:
Board [HASH=129]#1=17.4[/HASH]"
Board [HASH=130]#2=28.4[/HASH]"
Ball= 38.8"

Sum of the moments = M1(Board [HASH=131]#1)[/HASH] + M2(Board [HASH=132]#2)[/HASH] + M3(Ball)
=(17.4"x153lb) + (28.4"x153lb) + (38.8"x180lb)
=13,991 in-lb

No hitch extension and loaded to maximum rating of the receiver. I just found in my manual that the receiver can structurally handle 700lb, but shouldn't be loaded past 600lb because of vehicle's handling dynamics. The V8 can be loaded to 700lb. Maybe has HD suspension?)
Distance to ball = 16"
Sum of the forces in Fy = 700lb
Moment on receiver = F x D = 700lb x 16" = 11200 in-lb

So comparing the 2 scenarios. I have exceeded the moment on the receiver by 25%. But I am 70% the tongue weight rating of the receiver. I just don't think that the receiver is going to snap in half and cause catastrophic damage. I trust it to drive down the road and get my toys to the water. Maybe other people don't agree, but I will do periodic inspection of the receiver.

If anything, this conversation will help others see the mechanics of hitch extensions. It's the added moments on the receiver that reduce the tongue weight rating.

 

[swatski]

If anything, this conversation will help others see the mechanics of hitch extensions. It's the added moments on the receiver that reduce the tongue weight rating.

I don't think so.

Notwithstanding the silliness of having an academic discussion of something that involves an illegal practice (of operating a complex machine at highway speeds) let me cut to what I'm trying to say:
It is not the strength of hitch/hitch extender limiting the safety ratings here; rather, it is stability of the entire combo moving down the road.

The power of aerodynamic drag is impressive. One does not need to boat trailer on a highway to experience that power - if you ever launch in high crosswinds you will know the feeling. On the highway, gusts of wind of the passing of big rigs can cause trailer sway. Even with regular/short hitch (and no WDH or sway bars) that can be a handful.

While increasing tongue weight is a typical remedy, it does not work with a hitch extender due to added leverage. The bottom line: hitch extender is not the weak point here (albeit it can be), it is the tail wagging the dog phenomenon (the whole thing).

That's just my 0.02.
Over and out.

--

 

[2kwik4u]

I don't think so.

Notwithstanding the silliness of having an academic discussion of something that involves an illegal practice (of operating a complex machine at highway speeds) let me cut to what I'm trying to say:
It is not the strength of hitch/hitch extender limiting the safety ratings here; rather, it is stability of the entire combo moving down the road.

The power of aerodynamic drag is impressive. One does not need to boat trailer on a highway to experience that power - if you ever launch in high crosswinds you will know the feeling. On the highway, gusts of wind of the passing of big rigs can cause trailer sway. Even with regular/short hitch (and no WDH or sway bars) that can be a handful.

While increasing tongue weight is a typical remedy, it does not work with a hitch extender due to added leverage. The bottom line: hitch extender is not the weak point here (albeit it can be), it is the tail wagging the dog phenomenon (the whole thing).

That's just my 0.02.
Over and out.

--

This is a valid point.

I don't see the distance of the "before" hitch ball location, so I'll use my guestimate above of 16in. The current distance in the jetski on the tongue setup is 33.4. The force of the boat acting on the hitch has been multiplied by a factor of just over 2. So you can expect dips/sways/etc to amplified by the same factor.

If you are legitimately driving around the block (less than 1 mile) your risk is much lower than if you are trailering any prolonged time at speeds above city street normal ranges. It's still overloaded, and a bad idea IMO, but I'm not the one paying your insurance, vehicle maintenance, or lawyer bills......so, you know, there's that.

My biggest concern with posts like these are people new to towing and boating. They come here looking for advice and information, and quite possibly don't ask the question, but take "what someone else has done" as acceptable and run with it. This increases the chances of misinformation and misunderstanding becoming "gospel", or "rule of thumb" type information. My motivation is not to berate anyone, or to thump my chest, but to get good usable information out in the open so that someone that doesn't know the difference can make their own decision. Personal responsibility is still the name of the game, and if you are OK taking on the risk, then let'er rip, but do so knowing that just because someone else does it, doesn't make it a good idea.

 

[suke]

Not like I have any room to talk......BUT