Does anyone know of any software, web site, or formula that helps
determine how long a drawbar should be for a given trailer weight,
size, and axle positions?

Thanks in advance,
Dennis.

Does anyone know of any software, web site, or formula that helps
determine how long a drawbar should be for a given trailer weight,
size, and axle positions?

The correct term is 'ball mount'. There is a discussion about these
questions at:
http://www.timberman.com/RIG/trailer...omparisons.htm

Note that minimum 'ball mount' length has to be such that the tow and towed
vehicle will not collide during a maximum turn.

HTH

The welder who modified my power boat trailer into a sailboat trailer,
used a bathroom scale to see how long the trailer tongue had to be to
give a downward force of 200 pounds on the ball. He had to add 18
inches to the trailer tongue to get the rig to balance out but it was
really worth the effort and cost because the trailer & sailboat now
pull very well. The trailer tracks like it was on rails and the 18
inch addition means that, even in a very tight turn, the boat and tow
car never touch. In addition, the rig even backs much better than
previously.

I hope this helps.

Mike


wrote:
Does anyone know of any software, web site, or formula that helps
determine how long a drawbar should be for a given trailer weight,
size, and axle positions?

Thanks in advance,
Dennis.

wrote:
The welder who modified my power boat trailer into a sailboat trailer,
used a bathroom scale to see how long the trailer tongue had to be to
give a downward force of 200 pounds on the ball. He had to add 18
inches to the trailer tongue to get the rig to balance out but it was
really worth the effort and cost because the trailer & sailboat now
pull very well. The trailer tracks like it was on rails and the 18
inch addition means that, even in a very tight turn, the boat and tow
car never touch. In addition, the rig even backs much better than
previously.

I hope this helps.

Mike



Another advantage... you can back the trailer that much further into the
water without your tow vehicle wheels touching. Important for salt
water launching.

Will Sill wrote:

You appear to misunderstand. "Drawbar" is a farm implement term
irrelevant to rv use.

Actually, Will, a "drawbar" is used to semi-permanently connect two or
more pieces of rail equipment, such as a steam locomotive and its
tender, an EMD FTA and FTB pair as newly delivered, any number of well
cars in units of three to five, or those ubiquitous 85' flats drawbarred
in pairs so as to accommodate three 50' trailers.

Now tell this general lurker and occasional poster, why is (seemingly)
everybody on your case?

KH

wrote:
The welder who modified my power boat trailer into a sailboat trailer,
used a bathroom scale to see how long the trailer tongue had to be to
give a downward force of 200 pounds on the ball.

Serious questions coming up: How does a power boat trailer differ from
a sailboat trailer; isn't the "downward force" known as "tongue weight;"
and why could not the boat (whether power or sail) be repositioned on
the trailer so as to provide the (presumably) requisite tongue weight
regardless of type of load?

I ask the latter because, first of all, I do have a (ski) boat and
trailer (which I might like to use for a different boat), and I also
have an open frame trailer set up to haul several four-wheel rail
"speeders" (one at a time of course, but of varying weights), and I have
simply created wheel chocks to be placed at appropriate points on the
trailer frame depending on which speeder I am towing, so as to assure a
tongue weight of 150 pounds.

Ken Harrison

I would assume that the boat couldn't be loaded forward enough to get the
proper tongue weight without adding length to the front of the trailer.

--
JerryD(upstateNY)

Serious questions coming up: How does a power boat trailer differ from a
sailboat trailer; isn't the "downward force" known as "tongue weight;" and
why could not the boat (whether power or sail) be repositioned on the
trailer so as to provide the (presumably) requisite tongue weight
regardless of type of load?

"Ken Harrison" wrote in message
news
wrote:
The welder who modified my power boat trailer into a sailboat trailer,
used a bathroom scale to see how long the trailer tongue had to be to
give a downward force of 200 pounds on the ball.

Serious questions coming up: How does a power boat trailer differ from a
sailboat trailer; isn't the "downward force" known as "tongue weight;" and
why could not the boat (whether power or sail) be repositioned on the
trailer so as to provide the (presumably) requisite tongue weight
regardless of type of load?

I ask the latter because, first of all, I do have a (ski) boat and trailer
(which I might like to use for a different boat), and I also have an open
frame trailer set up to haul several four-wheel rail "speeders" (one at a
time of course, but of varying weights), and I have simply created wheel
chocks to be placed at appropriate points on the trailer frame depending
on which speeder I am towing, so as to assure a tongue weight of 150
pounds.


Sounds like you've got the problem cured on your "speeder" trailer! However,
boat trailers aren't quite so conducive to moving the weight around.
Difference between motor and sail(boat) trailers . . often the sail
trailer carries the boat much higher to account for a weighted keel. Doing a
complete rebuild of a trailer such as converting sail/motor you can do some
tongue weight shift in the design, but a longer tongue might be the more
practical way, plus giving you the advantage of the longer tongue.
To the guy who says his boat trailer tracks better and is "easier to
back" with the longer tongue . . absolutely! Many yrs. as an OTR driver
teaches you that a 48' trailer backs much nicer than a 45', and a 53' is
better yet. Never tried one of those 28-30' "pups" but know from talking to
others they are a "bi*ch" to back up.

--
Nahmie
The only road to success is always under construction.

"Will Sill" wrote in message
...

- I'm far too blunt for the PC crowd,

Why? Whatever happened to manners? It's not about PC, it's about what your
mother taught you about respecting other people.
--
Chris Cowles
Gainesville, FL

Norman D. Crow wrote:

trailer carries the boat much higher to account for a weighted keel.
Doing a complete rebuild of a trailer such as converting sail/motor
you can do some tongue weight shift in the design, but a longer
tongue might be the more practical way, plus giving you the
advantage
of the longer tongue. To the guy who says his boat trailer tracks
better and is "easier to back" with the longer tongue . .
absolutely! Many yrs. as an OTR
driver teaches you that a 48' trailer backs much nicer than a 45',
and a 53' is better yet. Never tried one of those 28-30' "pups" but
know from talking to others they are a "bi*ch" to back up.

I can attest to the fact that the 28' OTR trailers are a "bi*ch" to
back, UNLESS it's with a "yard jocker".

Tom J