Tongue weight on trailer?

[jackhartjr]

Hi folks, I have an Oday 22, I have a chance to buy a trailer.
My question is this; what is the maximum tongue weight I can have?
The trailer is 24 feet and is a tamdem. I know where the center weight of the boat is, and know that I can move it forward, I just need to know how much forward, therefore the need to know the maximum tongue weight!
Thanks in advance!

 

[Sailm8]

Here is a place to start. http://www.gmc.com/gmc-life/trucks/why-tongue-weight-is-important-for-safe-towing.html

 

[Leeward Rail]

While both Maximum and Minimum tongue weight are important...

If it is too LOW... the trailer will fishtail, which is devastating.

Do yourself, and everyone else you share the road with, a favour, contact a local professional and they can make sure your trailer and vehicle combination setup is safe.
Vehicle weight, trailer weight, trailer load, brakes, chain length/size, balance, tires, trailer axles, etc are ALL important.

Without knowing the details of your tow vehicle and hitch configuration there is no way to know the maximum tongue weight it can handle.

 

[Benny17441]

Could not say without knowing the capabilities of your tow vehicle. It is critical that the boat's center of gravity be ahead of the centerline of the axles.

 

[uncledom]

Boat+gear+trailer divided by 10 = good start point for tongue weight.
2000+400+800=3200/10=320lbs
Your vehicle and hitch must be rated to pull 3200lbs and have 320lbs down on it.
As soon as you go beyond the downward weight you must go to a load equalizing hitch which throws a percentage of the tongue weight up to the front wheels. Your tires need to be rated for your total weight as you have just added weight to them also. Go to a proper trailer hitch installation shop or back to your dealer for information about your vehicle and it's capabilities.

 

[Crazy Dave Condon]

As a retired dealer who helped in trailer design, Two things to remember. First as Unlcledom avidly pointed out, for safety when towing, 10% of the total weight of the trailer, boat, motor and gear should be on that trailer hitch for safety to help prevent fishtailing. Secondly, anything over generally 3000 pounds and/or tandem axles will require brakes on both axles in many states.. Suggest your state reequirements. There are reciprocal agreements between the states as to state laws. Good example, south Carolina does not require a tag on the trailer but must be pulled by a SC tagged vehicle. With a tandem axle is much better to have versus a single axle in way of swaying and so on.
As you move the boat forward, do you have a scale to measure the trailer tongue jack weight? In addition it would help to see a photo of that actual trailer. As for the axles you would have to see what the tires look like under load. Once you have configured the trailer, go out pulling it say for 20 miles and then physically check to see all hubs appear to be the same warmth.

 

[Daveinet]

I always found you can take the vehicle for a test drive and feel how it handles. At slower speeds, you can initiate a sway, and see if it wants to keep going, or recover. I find it pretty easy to tell when its not right.

You tow vehicle should have a spec for maximum tongue weight. Should be able to find that in your manual. Your boat is light enough, you may be able to read your actual tongue weight with a bathroom scale.

 

[Benny17441]

The ideal tongue weight falls within a range of good enough weights that prevent the trailer from swaying and at the same time allow proper and safe handling for the tow vehicle. This range has been estimated as between 9% and 15% of the trailer and load combined weight. This range allows for adjustment within the physical limitations of load balance and tow vehicle capabilities. While a big, heavy duty truck could handle a tongue weight of 1,000 lbs a family sedan might be hard pressed to handle 150 to 200 lbs. Check the trailer coupler to see how many pounds it is rated for. Understand that trailers when in motion impart dynamic loads; with bumps and road grades the coupler may oscillate up and down which will increase or decrease the actual tongue weight and there is safety factor built-in in the vehicle and hitch ratings. Exceeding the rated figures will eat into the safety factor. Work backwards and determine how much of a tongue weight your tow vehicle can safely handle and then limit yourself to that.

 

[jackhartjr]

Hi folks, thanks for all advice!
The truck is a 2015 Silverado High Country rated for 9,200 pounds towing capacity.
The trailer is a tandem with hydraulic brakes.
The only thing I haven't found is the maximum tongue weight rating for the truck, I'll look further this week!

 

[uncledom]

Well I would guess it won't be more than 1000lbs tongue weight which is just over 10% of the max tow weight.

 

[Daveinet]

Yes, as implied above, in order for your truck to be rated to tow 9200 lbs, the tongue weight must be rated for a minimum of 10% of that, or 920 lbs. If the truck only has a class IV hitch, (2" receiver) the hitch will be rated for 500 lbs.

So, your boat and trailer together are going to weigh around 3500 lbs. So you can easily put anywhere from 300 to 500 lbs of tongue weight and be perfectly fine. I would lean toward the high side, as the empty bed of your truck is light. Since your truck is going to be very forgiving on a heavy tongue weight, just fudge on the heavy side for the weight on the tongue. That will increase your safety margin, and give you better traction on the rear end.

 

[Drew13440]

Sheesh, I had visions of the OP trying to figure out if his Yugo would pull the boat. If the Silverado HC came with a factory tow package, it will pull an aircraft carrier. Ten to 15% tongue wait and off you go. Enjoy.

 

[JimInPB]

A few additional things to consider:

1) Please be sure that the 9,200# capacity applies to your particular truck, AS EQUIPPED. Not all 2015 Silvarados have the same transmission, axles, brakes, etc. Certain features can be added or deleted as factory options & that often changes the ratings.

2) Check the conditions under which that 9,200# rating applies. There are often 2 different ratings for trailers with & without brakes. The big rating sometimes only applies with load distributing hitches. It’s generally best to not believe what the salesman told you when you bought the truck. I like to look it up in writing.

3) The truck will have a tongue rating & a tow rating. The hitch will have it’s own tongue rating & tow rating. You are bound by the lower of the two.

4) Tongue weight is only part of the story. The concentration of the mass in the trailer over the axle is at least as important & is seldom considered. If you move 90% of the mass out towards the extreme front & rear of the trailer, while maintaining your 10% tongue weight, you will still have an unstable rig. If 90% of your mass is within a couple feet of the axle & you have even 5% tongue weight, you will probably be very stable.

5) The rigidity of the rear tires on the tow vehicle means a lot. Often changing from 4 ply tires to 6 ply tires will make a noticeable difference in towing stability.

6) Tire pressure matters. Please check it. Soft tires, especially soft rear tires, can cause lots of sway.

7) Please check that your trailer brakes actually work. Brakes on boat trailers (especially ones that see salt water) will generally need frequent maintenance. Since you said that you have hydraulic brakes, you might try backing up on a dirt road without the backing pin installed. On many trailers with hydraulic brakes, this should make the trailer tires skid in the dirt.

 

[Daveinet]

4) Tongue weight is only part of the story. The concentration of the mass in the trailer over the axle is at least as important & is seldom considered. If you move 90% of the mass out towards the extreme front & rear of the trailer, while maintaining your 10% tongue weight, you will still have an unstable rig. If 90% of your mass is within a couple feet of the axle & you have even 5% tongue weight, you will probably be very stable

Its a sailboat with a weighted swing keel.

I'm also not sure you are correct. What creates the instability is the weight being in near perfect balance, front and rear. An object will ALWAYS oscillate in perfect balance of its mass. If the pivot point and the center of mass are not at the same point, it can't oscillate, due to the miss balance. The only instability that can occur, would be a shift of the pivot point allowed by tire sidewall flex. It can ONLY oscillate around its center of mass.

 

[Rick Webb]

The further forward the center of balance is the more stable the trailer will be. 10% or so is a good compromise 20% would be better but makes a trailer tongue difficult to manage.

Center of mass and center of balance are two different things. The higher your center of mass is the more critical it becomes to have the rig level.

Remember making paper airplanes and putting a paper clip in the nose? Same principle. The trailer is going to want to lead with the heaviest part if the heaviest part is that closest to the tow vehicle it will stay in a nice equilibrium.

 

[JimInPB]

Its a sailboat with a weighted swing keel.

I'm also not sure you are correct. What creates the instability is the weight being in near perfect balance, front and rear. An object will ALWAYS oscillate in perfect balance of its mass. If the pivot point and the center of mass are not at the same point, it can't oscillate, due to the miss balance. The only instability that can occur, would be a shift of the pivot point allowed by tire sidewall flex. It can ONLY oscillate around its center of mass.

Yes, the weighted swing keel does put a good portion of the mass right where you want it & that is a good thing. Some other objects can be moved. It is usually best to put them as near to the axle & low as possible.

The effect of the mass being centered rather than being at the ends of the trailer can be explained using a gyroscopic stability equation or a moment of inertia equation or a torque equation, where the axle is considered to be the fulcrum (yes the tires do flex & therefor prevent the axle from being a perfect fulcrum).

You can do a little experiment to verify the effect with a piece of a wire coat hanger & a couple of 1 ounce "egg" sinkers from a tackle shop. Cut about 10 or 12" off the straight part of the hanger. tape the sinkers to the center of the hanger wire. swing the assembly in a circular motion from side to side in your fingers & see how it feels. Then move the sinkers to the outside edges of the hanger wire & swing it back & forth again. It will feel very different. With the weights at the outside edges, it takes much more force to start & stop the motion. The effect is the same when you load your gear in a trailer at the outer edges. Too much force out at the edges overcomes the grip of the towing vehicles rear tires on the road & the vehicle gets thrown sideways, as shown in the first video in a previous post.

Also, you state that a mechanical object can only oscillate around it's center of mass. Please consider the pendulum in a grandfather clock. Unless I misunderstand what you mean, the pendulum would seem to contradict that statement, at least from the perspective of the pendulum itself.

 

[Daveinet]

Hmm...Trying to adjust my mechanical model, because it seems it obviously had some gross errors. Not sure why I was not acknowledging the obvious. I think my brain was only acknowledging the rotational point in the center of the mass, and not considering the rotational point from the perspective of the hitch.

 

[JimInPB]

I agree with that perspective. The hitch can also be considered a fulcrum in a separate but equally correct & equally important torque equation.

 

[Crazy Dave Condon]

Although this is bringing a lot of thought and comments, the standard norm in the industry on tongue weight is 10% of the total load on the hitch. Those manufacturers have been down that road and I considered them to be the experts. As for the axles, they have to be adjusted or moved unless the trailer was specifically designed for the boat like the Hunter water ballast trailers and one for the Catalina 22 Sport which I was involved with in that design for the Sport version but also works well for Catalina 22 swing keel versions only. When all said and done, going down the road for 10-20 miles checking the hubs is one key but another factor is load range of all the tires to carry all the weight.

 

[MrBill_FLL]

http://www.eyershitch.com/images/BookGraphics/meastung.jpg

^ bathroom scale mod for tongue weight.

sway control and weight distributing hitches work. also go slow. heat kills tires. and trailer tires will blow out, just a matter of time.