tongue weight question

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
I just picked up a REALLY nice EZ Loader trailer that needs just a little work.
it has a torsion axel!
8' bunks with glides
all galvanized

model EZW1418 2300 lbs

I want to adapt it to my new boat which is already set up on a previosuly reworked super heavy duty trailer.

the new trailer has surge brakes and I think i could use them so i want to make this switch.

first thing I need to figure if i can do it, is how much I "COULD" move the axel on the current set up to give me more tongue weight

that wil allow me to establish a set distance from the BACK of the trailer were the transom HAS to be and from there, i can figure if the trailer will be long enough or if i need a new tongue tube.

right now the tongue weight is 70 lbs

the boat weights about 1100 lbs and ia a 20 ' aluminum Mod V.

with two 9 gallon portable gas tanks up front and one battery in the middle. not much other gear

I have a 325 lb outboard on the back of a 10 set back jack plate.

I have exactly 70" from the bottom edge of my transom were it meets the hull to the center line of my axel

the new trailer would be hard pressed to make that 70" but the mid 60's is doable...so i need to know how much I can move the axel to get maybe another 70 lbs of tongue weight.(max 140lbs)

I dont want to the tongue too heavy that i have a hard time move the trailer over to the ball on hook up.

a tree fell on a guys 17 foot BASS TRACKER deep V bow and he scrapped the boat, sold the motor to my buddy and now i boat the trailer which the long tongue tube is bent, for.....$100

it is a 1995 trailer.....

thanks

bob
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

too much info?

not enough?
no trailer experts here?

everyone on vacation?

the trailer and boat weigh 2500lbs..
just weighed them today..

maybe i'll just go through the motions of trial and error

bob
 

robert graham

Admiral
Joined
Apr 16, 2009
Messages
6,908
Re: tongue weight question

Einstein couldn't calculate that! Maybe put the boat on trailer, check tongue weight, if too heavy then slide boat back about an inch at a time until you get the weight you want/need. good luck!
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

the trailer the boat is on now has holes for adjustments..and they are like 12" apart....

the new trailer has a sliding frame carrying the axle assembly and can be adjusted like you say.

i would hjave liked to figure if the new trailer would fit and were everything MIGHT be, before i started down that road of changing trailers!!

I found a monster calculation but it has tooo many formulas

but one variable that was needed, i didnt have until today...the weight of everything

bob
 

rbh

Fleet Admiral
Joined
Mar 21, 2009
Messages
7,939
Re: tongue weight question

I am not totaly sure but from what I have read, most people go with 10% of the gvw as the tongue weight, providing your vehicle can handle it.
Best bet is to call or e-mail the mfg for their take on it.
rob
 

RICHARD5

Petty Officer 2nd Class
Joined
Aug 8, 2009
Messages
150
Re: tongue weight question

It is easily calculated except the OP was too inaccurate. EX: "a couple of portable 9 gallons tanks up forward" is too inaccurate. How far fwd? Knowing the gross wt of the boat isn't enough information. We need to know how the wt is distributed along it's length.

An accurate calculation of weights and moments requires an accurate statement of specific weights at specific arms. That is if you want an accurate calc for tongue wt.

Ballpark guess, I'll say the axle will move aft an inch or two. I doubt >4". And for that tongue wt to remain a constant, the boat would have to be loaded the same, on the trailer and in the boat. I think the best best you could get is a range of tongue wt as opposed to a specific tongue wt.

The challenge is for the OP to provide accurate weights and measurements.

--OR--​

The down and dirty method.
Load the boat as typical. Raise the trailer off the ground with jacks. Using a scale, measure the wt at the tongue. (Force to lift the tongue). Adjust the jacks aft to derive desired tongue wt. The centerline of the jacks now indicates new axle centerline.​
 

cribber

Lieutenant
Joined
May 29, 2008
Messages
1,338
Re: tongue weight question

Your ideal tongue weight should be in the neighborhood of 9-15 percent of total wiehgt so an ideal 12% would be 300# and gives you wiggle room. Load your boat for a typical day out on the water and then make your adjustments. Whether you move the axle or the boat on the trailer go with which is easiest. Likely you're in the ball park as is...
 

RICHARD5

Petty Officer 2nd Class
Joined
Aug 8, 2009
Messages
150
Re: tongue weight question

Your ideal tongue weight should be in the neighborhood of 9-15 percent of total wiehgt so an ideal 12% would be 300# and gives you wiggle room. Load your boat for a typical day out on the water and then make your adjustments. Whether you move the axle or the boat on the trailer go with which is easiest. Likely you're in the ball park as is...

Oh fine, give a simple answer for a simple problem. :D
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

It is easily calculated except the OP was too inaccurate. EX: "a couple of portable 9 gallons tanks up forward" is too inaccurate. How far fwd? Knowing the gross wt of the boat isn't enough information. We need to know how the wt is distributed along it's length.

An accurate calculation of weights and moments requires an accurate statement of specific weights at specific arms. That is if you want an accurate calc for tongue wt.

Ballpark guess, I'll say the axle will move aft an inch or two. I doubt >4". And for that tongue wt to remain a constant, the boat would have to be loaded the same, on the trailer and in the boat. I think the best best you could get is a range of tongue wt as opposed to a specific tongue wt.

The challenge is for the OP to provide accurate weights and measurements.

--OR--​

The down and dirty method.
Load the boat as typical. Raise the trailer off the ground with jacks. Using a scale, measure the wt at the tongue. (Force to lift the tongue). Adjust the jacks aft to derive desired tongue wt. The centerline of the jacks now indicates new axle centerline.​

and i thought I might have given toooo muich info!!!

battery in the middle, 325 lbs motor TEN INCHES OFF the transonm ON a JACK PLATE!!!

boat weights very close to 1100 lbs.

UP FRONT means...under the front deck..maybe the center of the tanks are 3 feet from the tip of the bow....

which is 20 feet from the transom

and the transom is 70 " from the axle..

side to side is even weight distrubution..

center console is almost exact in the center of the boat...but not the center of gravity...with that heavy motor cantilevered off the back of the transom


I actually am having issues with so much rear weight.....

BUT I CERTAINLY dont want 300 lbs of tongue weight!!!!!!!...

Id hardly be able to lift and move the trailer around.


If I fashion a transom saver to take the rock off the motors momentum on bumps will that change my center of gravity?

I actually like the two jack stand idea.... the springs might be in the way though.....

ill try it this weekend

bob
 

mike343

Petty Officer 1st Class
Joined
May 4, 2009
Messages
284
Re: tongue weight question

Tongue weight for BOAT trailers should be between 5 and 10 per cent of the towed weight--go to the trailer manufacturers' web sites if you don't believe me, e.g. Load-Rite. Or check the actuator supplier's site.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

moved the axle carrier back to the next set of holes( about 8-10") asnd the tongue weight went from about 70 lbs to 110lbs.


big difference...the light tongue was casing a lot of problems.. the trailer was going to eventually self destruct!!

the boat was always trying to come off the winch.. and it was beating the tilt latch to death...now I need to replace it.

bob
 

dtskidoo

Cadet
Joined
Jun 24, 2007
Messages
16
Re: tongue weight question

10% of weight should be on tongue.Invest in a trailer tongue jack it will be the best 30 bucks you ever spent.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

got a wheeled jack......but doesnt roll on grass and dirt where I park the trailer.

I moved the axle carrier AGAIN yesterday another set of holes....

because i had 110 lbs of tongue weight AND my tansom was 6 " in from the end of the bunk and I have transom straps that are hooked to an eye bolt at the end of the trailer!!! so id like to move the boat back!! to the end of the bunks!!

now the tongue weight is 170 lbs!!

bob
 

rockyrude

Lieutenant Junior Grade
Joined
Sep 10, 2007
Messages
1,120
Re: tongue weight question

Having a little bit of bunk out the back is actually a good thing for support. Having the correct tongue weight is pretty critical to the trailers life and your safety, too little and it'll dance all over the place, too much and you get steering issues. You will need to try and devise a way to move it when off the tow vehicle.
 

bob johnson

Rear Admiral
Joined
Feb 25, 2009
Messages
4,304
Re: tongue weight question

at a tag sale here a guy was unloading all his boating stuff after a tree fell on his tracker.

he gave me a dolly with like 12" dia wheels and a ball on a pivot point to move trailers around...

I hope the wheels are large enough to make moving my trailers around easy, on the uneven grounds.

all the time i had too little tongue weight for this trailer( 3 months now) it was never swaying and unstable...other than hinging a lot...which since it is a tilt trailer, it tried to tilt up constantly. And that would try to loosen my winch strap...

one thing that is not in most forumlas for figureing trailer set up is HOW FAR Back the motor is on the boat...I have a 10 " set back... so i have 325 lbs set 10" back off the end of the transom...that really changes the center of balance for this set up...

when i orginally set up the trailer , it was without the motor!!!! and the tongue was very heavy!!!

once huung that motor wow the tongue lightened like crazy!!

bob
 
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