What should the tongue weight be on a boat trailer?

[sbklf]

It seems there was a thread on this not to long ago and someone had a formula for it. I searched for it with no luck. I found one site says 9 to 15% of the total weight of the loaded trailer but that seems high. I figure my rig weighs about 3500 lbs, 10% would be 350lbs, that seems high to me.

[Bond-o]

10% would be 350lbs, that seems high to me.

Ayuh,.... That's Correct,+ the Minimum at that...

[kenmyfam]

10% to 15% is a good guideline. See how it performs and adjust from there. Check it out on the bathroom scales.

[Texasmark]

A general purpose, commonly used, Class II, receiver hitch is rated to 5,000# tow capacity with 10% tongue weight capacity. Add antisway trailer towing tensioner and it goes up 2x.

You need the tongue weight to keep the trailer stable while towing and I guarantee you don't want to be near one that is blasting down the interstate and goes unstable. I've seen a 16' tandem utility trailer take both lanes and the shoulder and in the process take out both rear panels on a P/U truck and it happened in a heartbeat; one heartbeat. It tain't pretty. it's unbelieveable how fast that a seemingly otherwise stable trailer can move that far, that fast.

Also, interstate again, the lighter the tongue wt. the easier it is for a passing semi, expecially the ones with the big boxes in tow, to suck the boat over in their lane and after they pass, the vacuum is gone and it turns your boat loose causing it to move (overshoots) back in your land and wiggle for a minute while it settles back down.

Don't worry about lifting the tongue; just store it on a concrete floor and use a good quality dolly wheel; piece of cake.

HTH

Mark

[jeeperman]

The above advice comments are valid.

Yet my boat and trailer weigh around 4000lbs and there is maybe 250lbs on the ball.
Pulls straight and stable at all speeds.

The aerodynamics of your tow vehicle and trailer combo will have an effect on what the magic number is too.

[Silvertip]

Some trailer manufacturers suggest as little 7% but I suspect that is out of sympathy for those with the marginal towing capacity of many of todays vehicles that are being used for towing but shouldn't be.

[sbklf]

Great information, thanks, it is 80 lbs now, I will make the adjustment. Kevin

[Texasmark]

The above advice comments are valid.

Yet my boat and trailer weigh around 4000lbs and there is maybe 250lbs on the ball.
Pulls straight and stable at all speeds.

The aerodynamics of your tow vehicle and trailer combo will have an effect on what the magic number is too.

No offense bro, but you can bet your bippie they are valid; they are actual real life events and with a '71 Chev full sized station wagon, 400 cu in, 18' Caravelle, 125 Johnson, custom trailer, brakes and all the goodies, 13" 6 ply TS tires and all driven by a guy that doesn't like road problems......BTDT

Mark

[jeeperman]

No offense bro, but you can bet your bippie they are valid; they are actual real life events and with a '71 Chev full sized station wagon, 400 cu in, 18' Caravelle, 125 Johnson, custom trailer, brakes and all the goodies, 13" 6 ply TS tires and all driven by a guy that doesn't like road problems......BTDT

Mark

uuhhh well okay ?

[mike343]

I find these responses not very helpful. You can go to BOAT trailer sites, get their manuals, and go to actuator sites and look at their manuals--ALL SAY 5-10%. But the tow vehicle manuals say at least 10%.

I am probably close to 15K mi with a 5500# trailer at 6% TW. Tows beautifully, handles difficulties easily, no sway,pitch, etc.

Maybe someday the tow vehicle mfgrs (and their lawyers) will admit that boat trailers and travel trailers are different.

[smokeonthewater]

well my tow rig is a 10,000 lb dually and you could put a 3000 lb trailer with no tounge weight behind it and it would be no problem..... put that same trailer behind a mini truck and you have big problems..... just because you can get away with it for at least a while does not change the fact that 10% is the recognized minimum safe target.... where your 6% works well for you a controlled test with an emergency manuver with that setup and another with 10% or more would show that an increase in tounge weight would make for a MORE stable rig in most if not all situations

[Mark_VTfisherman]

I agree that over 10% tongue weight is better. The question I often have when reading tongue-weight discussions is why are people are so defensive about their light tongue weight setups? If one is towing a 3500lb package, I would hope they would be towing it with something that is sufficient to handle 350lbs on the hitch. Plus, who wants to listen to the hitch banging up-and-down on the ball?

Maybe some live in the world of flat, smooth, wrinkle free paved roads, but at least here in New England with all the frost heave damage, pot holes, and winding roads, I can't imagine why you would want a lighter tongue weight.

[kenmyfam]

I find these responses not very helpful.

Sorry to hear that !!
The responses given I believe were from personal experiences by each person. Actual experience counts a lot more than booksmart in real life. Ask a newly qualified engineer on the first day in a manufacturing environment.
Just my 2 cents though and not intended to offend.

[Gary H NC]

First hand experience,
When i bought my boat the axles were adjusted too far forward.
It towed fine up to about 60 mph.Then it would start to sway very bad and about wrecked me.
The tongue weight was at 240 lbs.
I adjusted the axles back to the next hole and that put my tongue weight at near 500 lbs..
I can tow at 70 mph and it is rock solid. No sway when passing or being passed by big trucks at all now.

Guessing my boat is about 4000 lbs loaded with trailer so i am well over the 10%.

So hopefully this info is helpful.

[ezmobee]

My boat was like Gary's when I bought it only worse. I think I had about 3 pounds of tongue weight It didn't tow well at all. Very herky-jerky. I just finished moving my axle back like 3 or 4 holes. Haven't towed it yet (and it will be a while) but I expect a major improvement.

[smokingcrater]

well my tow rig is a 10,000 lb dually and you could put a 3000 lb trailer with no tounge weight behind it and it would be no problem.....

problem is that your trailer really doesn't care what is towing it. if you have no tongue weight, a swaying trailer won't take you off the road, but it certainly can damage alot &/or toss whatever is on the trailer completely off. Trailers start swaying because of road conditions/speed/tongue weight. Has nothing to do with what is pulling it. That only affects what happens AFTER the swaying starts.

(and don't underestimate a 3000 lb load. i've personally seen bass boats flip trucks that heavy. Once it builds up momentum all bets are off...)


One thing to keep in mind about measuring tongue weight... don't set the tongue directly on the scale. You want the trailer at the same attitude that you tow it at. use a block/jackstand on the scale and then zero it out mathmatically. If a boat sits high on a trailer, tongue weight will be SUBSTANTIALLY heavier on the ground vs normal height.

[NYBo]

Low tongue weight also puts more of a strain on the coupler- its weakest link is the tang that engages the ball (whatever it's really called) so the less bounce against it, the better.

[smokeonthewater]

reread the WHOLE post crater
I promise I don't underestimate anything.... I have towed with a gross vehicle weight of over 240,000 lbs on more than one occasion..... obviously the example is of what not to do.... the point was that just because you could get away with it doesn't make it right
on a sidenote until you have towed with a crewcab diesel dually you will not understand... that little bassboat could sway until it ripped the trailer in half and would just be an annoying wiggle to the truck....... now that's not saying it wouldn't be scattering peices over 3 lanes....

EDIT.... let me go ahead and add that doesn't mean that just anyone could handle it or that it would be a good idea just that there is a HUGE difference between towing with a short wheelbase soft sprung suv ... vs a truck specifically designed for towing...and that just cause some guy gets away with towing a tail heavy trailer doesn't mean it should be preached as the next guy could be trying to do it with an exploader or a tracker

[kenmyfam]

I have towed with a gross vehicle weight of over 240,000 lbs on more than one occasion

240,000 lb ?????
What were you towing and what with ????
Quite the tongue weight discussion there !!!

[smokeonthewater]

BIG caterpillar stuff..... mack r model and lowboy....never got over 20mph.
wasn't really relevant.... just throwing out big numbers to make myself look cool ...... lol

[SS Flasher]

on a sidenote until you have towed with a crewcab diesel dually you will not understand... that little bassboat could sway until it ripped the trailer in half and would just be an annoying wiggle to the truck...

Just last summer I saw a beautiful ford truck like the one described off the road and severely damaged. True, the boat took the worst, it had flipped a couple of times and pieces of it were everywhere. Witnesses said the trailer apparently started to sway violently, came off the trailer, and threw the truck out of control.
Why would we be concerned with a little more tongue weight on a perfect tow vehicle like this?

[jeeperman]

Many a small tail have wagged a big dog, LOL

[Texasmark]

problem is that your trailer really doesn't care what is towing it. if you have no tongue weight, a swaying trailer won't take you off the road, but it certainly can damage alot &/or toss whatever is on the trailer completely off. Trailers start swaying because of road conditions/speed/tongue weight. Has nothing to do with what is pulling it. That only affects what happens AFTER the swaying starts.

(and don't underestimate a 3000 lb load. i've personally seen bass boats flip trucks that heavy. Once it builds up momentum all bets are off...)


One thing to keep in mind about measuring tongue weight... don't set the tongue directly on the scale. You want the trailer at the same attitude that you tow it at. use a block/jackstand on the scale and then zero it out mathmatically. If a boat sits high on a trailer, tongue weight will be SUBSTANTIALLY heavier on the ground vs normal height.

Sir I totally agree with you on both points and they are very well advised.

Mark

[jfadool]

I have been around some big trailers. 12000lbs is a lot of trailer and when I load them I try to load them front heavy. I am not worried about tongue weight with a dulley. But if I can get 20-25% tongue weight I am a very happy person.

My thought is: To light on the tongue and I will have problems, more tongue weight will not hurt, the truck can take it no problems. Load your trailer properly, tow with the correctly rated vehicle and you will be in good shape.

[smokeonthewater]

oh well I give up.... my point was that getting away with it doesn't make it right...... cheers

ps the last trip I made was 2 weekends ago to philly and back to pick up a 9000 lb cruiser .. we set it up with about 1500 lb tongue weight ..... made it 750 miles home with 2/3 of that in a blizzard