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My 20' BoJest is on a double axle aluminum trailer, and as now confugured, I have a tongue weight of about 400 lbs.

I am going to get the boat and trailer weighed next week, and once I have that figure, I want to adjust the boat for optimal tongue weight.

My question is what percentage of total boat/trailer weight should I shoot for as tongue weight??
A quick internet search resulted in figures from 5% to 15% -- quite a range!!

BTW - my trailer alone weighs 650 lbs and I am guessing the boat to be around 2800 fully loaded.

Can anyone help?

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Tom
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Knot-So-Fast (A stretched Bo-Jest design)
Travel Log at www.tomstug.blogspot.com

"It's amazing what one can do when one doesn't know what one can't do." - Garfield

The first thing to look at is do you have any adjustment in your running gear for your trailer if you have too much. Most galvanized ones do have this option while the aluminums seems to be built with little to none unless the trailer is a very expensive one too. The rule of thumb seams to be around ten percent of the total weight and working your way up for marginal but tolerable amounts depending on the vehicle and setup for your ramps for the undercarriage to be on solid ground too.

Positioning on the trailer is pretty much etched in stone in regards to overhang. So we end up adjusting the axle and components in the under carriage. Keep in kind when doing so that the courtesy lights along the wheel wells may need additional work on the wiring if the lights are wired at the factory which is normally run inside of tube channels, if applicable.

But anyway with some trailers you may not be able to adjust your tongue weight. But its important that you do not have too much as this will cause your vehicle to steer funky too.

How does it tow now Tom?

Does it fishtail or sway?

Does the tow vehicle sag low under the hitch weight?

You need enough to eliminate sway

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Boat building can best be defined as an endless series of
tragedies obscured by the occasional miracle, followed by a good bottle of beer.

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It pulls pretty well, but not perfect. I've been hesitant to pull it above about 60mph, until I was sure that I was at least in the ballpark on the tongue weight. No swaying or fishtailing, but it feels pretty heavy on the truck when you hit dips or bumps.

Oyster, my thought was to slide the bunks and bow winch (and thus the boat) back a few inches to achieve the proper percentage of weight on the tongue. This will be far easier than messing around with axle placement.

My real concern is what percentage of the total boat/trailer weight do I want for a tongue weight.
Should I shoot for 5%, 15%, or somewhere in-between??

_________________
Tom
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Knot-So-Fast (A stretched Bo-Jest design)
Travel Log at www.tomstug.blogspot.com

"It's amazing what one can do when one doesn't know what one can't do." - Garfield

Tom

I shot for 10%. I'm inthe same range that you are talking, towing weight about 2400 to 2800#. I can lift the tongue sometimes. But, I can't do anything with it when I do.

Bill

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Mini -Tug, KH Tahoe 19 & Bartender 24 - There can be no miracle recoveries without first screwing up.
Tahoe 19 Build

Well using a formula as the only guidline is not always the best. First off most states have laws on the books that states the maximum hangover from the backs of the trailer and lights, and tag too. This may or may not come into play too. Shifting axles when the setup allows you to do so is really pretty easy, especially if you have too much weight foward. Keep in mind certain bunk arrangments and particular bottoms creates another set of circumstances and unintended consequences too. Maybe post a good photo of the profile and maybe a shot looking foward from the transom, as all my rambling maybe mute.

Unless you're pulling that with like a 3/4 ton truck and a Class V hitch, I'd be scared to death to have 450lbs of tongue weight. That seems like way too much for me. The normal bouncing up and down while traveling down the highway will cause a lot of instantaneous shock loads that could fatigue the hitch into a failure in the future. Believe it or not, the proper weight should be in the 60 to 120 pound range.

However, having too much tongue weight will not cause it to sway. Swaying is caused by having to little tongue weight. When the trailer is tail heavy it starts doing the snake.

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Isn't it amazing!! The person that never has the fortitude to pursue his own dreams, will be the first to try and discourage you from pursuing yours.

upspirate hit on a good remark:
Does the tow vehicle sag low under the hitch weight?
I have found this to be a better determining factor than merely figuring tongue weight. tonque weight of xx% dont matter if the tow vehicle isnt sized to tow the trailer.
I have never had a towing problem if the tongue weight does compress the tow vehicle suspension approx 2". The lighter the tow vehicle, the less tng weight to compress its suspension 1-2". If you dont compress the suspension (light tng weight) you gonna get sway and dangerous braking.
If you compress suspension too much, you get those hard shocks going over bumps, and yes it will feel heavy.
This works out quite well, especially if you go retreive a strange boat with your vehicle, you adjust for a good hitch weight as I said, and away you go. Even the dually trucks dont compress suspension 4-6" or anything like that, about 2" with a gooseneck or 5th wheel. However 2" on a dually is about 1000-1500# on a 5th wheel hitch.
I got a 25' inboard boat behind a 3/4 ton diesel pickup, you guessed it, about 2" of tongue weight and it tows fine.
Hitch height is another factor, the trailer frame should tow in a level attitude.

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God Bless our Troops; especially our Snipers

While many points have their merits Kens, its very important that the overall weight is carried across the trailer's undercarriage evenly too. Of course each trailer varies too. BUt as long as your trailer is rated for the load, displacing it is still key. A two inche compression is pretty broadbrush for sure and can vary with the vehicle. His boat is pretty tall and weighted foward. FWIW, I think he is towing with a Toyota Tundra.

Tom,
If your estimated weigths are correct you are at 11.6% tongue weight now. One thing I want to add to the fine points already made. Don't just go by the hitch ratings, but also check the tow vehicle owner's manual for tow ratings.

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A secret to a good marriage is to have a quick mind and a slow mouth!!!

I too agree with Ken. The numbers are a guideline. For tongue weight my Ford truck manual suggest from 10% to 15%. My trailer manufacturer suggest from 5% to 8%. Who do you believe? In my opinion it all comes down to how it tows. If it has a tendency to sway, odds are you need more tongue weight. If hitting bumps and dips in the road make the suspension bottom out or the rear end squat the then you have too much tongue weight. If you can't cure one problem with out inducing the other - you need a bigger tow vehicle. (NOTE - The one number that should always be followed is the Maximum Trailer Weight described by the manufacturer)

In my case I am towing about 7500 lbs and have about 550 lbs on the tongue. This calculates out to a little over 7%. It tows very well with no tendency to sway - at least up to about 70 mph as that is as fast as I have gone. Normally run at about 60 mph. I am towing it with a 1/2 ton truck with a class V hitch. My 09 Ford F150 2wd is rated for a 9800 lbs trailer. By Fords numbers I could but 10% of that on the tongue but I tried sliding the boat forward and filled the forward water tanks (80 gallons) which pushed the tongue weight up to 725 lbs and it pounded the rear suspension. For me it was too much no matter what Ford states. Actually I would like to try pulling a little more weight off the tongue as see what happens.

Also, one positive result of having more tongue weight is traction at the ramp. Initially I had real concerns about dragging that much boat out of the water and up the ramp. Would wheel spin be a problem with only 2wd? Well, it has proved to be no problem and I accredit most of the to the tongue weight.

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So Many Rivers,
So Little Time....

Too much tongue weight will cause you to loose steering too even though as Ray says you may end up with added traction at the ramp. Tandem axle trailers react a bit differently and the fudge factor is a bit greater. At the end of the day if your trailer is not loaded within its specs and balance, your tow vehicle tires can and will also heat up especially if you have not checked your tire pressure either lately. One of the telltell signs of any general overloading of any trailer is to first look at the tread wear of the tires.

Keep tabs from trip to trip. Of course the wheel bearings needs to be repeatedly lubricated because of the water that creeps into them from multiple launchings. So don't forget that if you also are planning for a long trip too after using your trailers locally.


If you have ever done any RV towing, the first thing that will be in order is to use a three way hitch setup with weight distribution bars, which transfers the weight back to the running gear of the trailer because of the loads and fixed parts.

Oyster, glad you brought up the weight distribution hitch. I have never seen one on a boat trailer but wondered about using one. Does anyone have experience with using one with a boat? I thought the lack of use might be because of the odd angles sometimes incurred between the trailer and tow vehicle on ramps but seems like it shouldn't be a problem. Any experience anyone?

(Interesting thread!)

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So Many Rivers,
So Little Time....

I have not used weight dist hitch on a boat trailer, but I used one on a RV. I towed a 30' rv on a reciever hitch with weight bars on it. I didnt like the hassle to hook it up, didnt like the double bumps you get when hitting a bump. So, one day I was in a hurry to move across town and went without the bars. Didnt notice much. So the next trip I went carefully up the interstate without the bars just feeling it out. The next trip I just left the bars in storage.
My point being, if you got enough tow vehicle, you dont need to scrrew around with the weight distribution bars. It is much simpler too.
My feelings is that the weight dist bars are there to extend usage of a inadequate tow vehicle.

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God Bless our Troops; especially our Snipers

Funny you should say that. Sorry Kens with all due respect take a look at the most common tow vehicle for rvs, the 3/4 ton Surburban comes to mind right behind the Cummins Diesel Dodge both of the days gone by and the present. Inadequate tow vehicles they ain't and you will find them on just about all of them, especially along the interstates. Ever been to Camping World? If so the parking lot is filled with dog eared hitches which accepts the bars.

The setup of the weight bars along with the sway bars are not common on boats since the hitch setup is different too. I mentioned them in the context of the rigid setup of all travel trailers unlike boat trailers and trailers proportioned to the sized hull which also sizes the undercarriage proportionately which also in many cases are adjustable.

Travel trailers also do not have the advantage of counter weights like power boats with a big refrigerator hanging off the butt end of those types of boat. The setup is as common as baseball and hotdogs unless you have a massive tow vehicle and a teeny tiny trailer.

Sway bars are really easy to use though on boat trailers which has just the straight tongue without the vee feature that the travel trailers use.