Drawbar Length - How Long?
 

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.

Drawbar Length - How Long?
 

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

Drawbar Length - How Long?
 

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.

Drawbar Length - How Long?
 

Drawbar Length - How Long?
 

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

Drawbar Length - How Long?
 

Drawbar Length - How Long?
 

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?

Drawbar Length - How Long?
 

"Ken Harrison" wrote in message
.net...
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.

Drawbar Length - How Long?
 

"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

Drawbar Length - How Long?
 

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

Drawbar Length - How Long?
 

Lengthening the trailer tongue is a different matter from lengthening the
distance from the ball on the ball mount to the tow vehicle.

In the former, the center of gravity of the boat/trailer is farther from the
center of gravity of the tow vehicle, but that by itself doesn't make much
difference in towing and handling (all else being equal).

However, if the distance from the tow vehicle to the ball mount is longer,
any sway in the trailer has much more of an effect on the handling of the
tow vehicle. Think of a lever and fulcrum. The longer the lever from the
fulcrum, the more movements are magnified.

Common lengths, from the hitch pin hole to the ball hole, are around 8
inches, with the longest I have commonly seen about 11 inches (and the
shortest something like 6 inches). Not all hitches have the same distance
from the back end of the hitch to the end of the vewhicle (bumper...), and,
of course, not all vehicles have the same distance from the center of
gravity or the rear axle to the hitch. Therefore, I would imagine that the
length of the ball mount in the ranges commonly available will not have much
effect on towing. The most important factor is probably tight turns, with
the trailer not running into the tow vehicle (pretty hard to do with a
standard pop-up configuration!).

Note that there are hitch ball mount 'extenders' available in lengths up to
18". These usually state in the fine print that the maximum towed weight
should be reduced by 1/3 if using these, and I would also imagine that any
sway in the trailer could be dangerously amplified.

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.

Drawbar Length - How Long?
 

"tobe" wrote in message
. ..
Lengthening the trailer tongue is a different matter from lengthening the
distance from the ball on the ball mount to the tow vehicle.

In the former, the center of gravity of the boat/trailer is farther from
the center of gravity of the tow vehicle, but that by itself doesn't make
much difference in towing and handling (all else being equal).

However, if the distance from the tow vehicle to the ball mount is longer,
any sway in the trailer has much more of an effect on the handling of the
tow vehicle. Think of a lever and fulcrum. The longer the lever from the
fulcrum, the more movements are magnified.

Common lengths, from the hitch pin hole to the ball hole, are around 8
inches, with the longest I have commonly seen about 11 inches (and the
shortest something like 6 inches). Not all hitches have the same distance
from the back end of the hitch to the end of the vewhicle (bumper...),
and, of course, not all vehicles have the same distance from the center of
gravity or the rear axle to the hitch. Therefore, I would imagine that
the length of the ball mount in the ranges commonly available will not
have much effect on towing. The most important factor is probably tight
turns, with the trailer not running into the tow vehicle (pretty hard to
do with a standard pop-up configuration!).

Note that there are hitch ball mount 'extenders' available in lengths up
to 18". These usually state in the fine print that the maximum towed
weight should be reduced by 1/3 if using these, and I would also imagine
that any sway in the trailer could be dangerously amplified.


Agreed. Ideally, you want the actual ball mounting position as close to the
rear axle of the tow vehicle as practically possible. If you ever take note
of the guys who transport mobile homes for a living, they are generally
driving a single axle road tractor that has been modified to put the ball
mount as close to the rear axle as possible. Someone in this thread
mentioned an "obscenely expensive" hitch that makes believe the hitch point
is @ or near the rear axle, good thinking.

This is why, with an OTR history, I chose to go 5th wheel. I've seen too
many trailers towed by ball hitch where the tail started wagging the dog.

I wasn't aware they made ball mount extenders, but the very thought scares
me. Same thought as going down the road with my 16K slider in the
maneuvering position.

Ladies & gentlemen, I haven't lurked here long, so if my statements are
objectionable, feel free to fire away. Cut my teeth in Usenet & always wear
the flame retardant undies. I'm making statements about things I think I can
contribute to, but there's a whole lot about RVing I DON'T know, and may
likely ask some stupid(to some) questions(then again, the only stupid
question is . . . ).

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

Drawbar Length - How Long?
 

"Will Sill" wrote in message
- I'm far too blunt for the PC crowd,

How about the Mac guys??

Drawbar Length - How Long?
 

Dave Lee wrote:
"Will Sill" wrote in message
- I'm far too blunt for the PC crowd,

How about the Mac guys??

################################################

MY RESPONSE IS "WILL SILL FOR PRESIDENT!"

+++Now that our current President "Shrub" has demonstrated his complete
lack of ability to govern a complex nation of intellectuals such as
ourselves, it is obviously time for a change. And who better to step
in and fill the void than the omnipotent and incredible storehouse of
human knowledge called Will Sill.

+++The length and breadth of Will's massive intellect is just what this
nation needs to extricate us from the depths of mismanagement and
horror in which we now reside. Mr. Sill, the mental giant of Usenet,
could use those same all-encompassing skills to bring us to a new
dawning of consciousness.

+++His astute and crystal-clear concept of reality could forge a "new"
nation capable of surmounting any and all previous apices of success
and perhaps even provide us with a new nickname --- "The Nation That
RVs Built." Not only would the power of his intelligence be of use but
his drop-dead, adonis-like muscular looks would present an image to the
world that we are a country not to be "messed with."

+++Pay heed, America, listen to the new voiceof reason. In the next
presidential election write in the name ofour beloved Will Sill and
prepare thyself for a new and better tomorrow.

-RV Mama

(PS--And ladies, remember, Will is one hot and sexy dude too...that
should count for something!)

Drawbar Length - How Long?
 

Will Sill wrote:
I see where contributed:
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?

You appear to misunderstand. "Drawbar" is a farm implement term
irrelevant to rv use. Your hitch ball should be as close as possible
to the tow vehicle, regardless of "trailer weight, size, and axle
positions" The best hitches (PullRite and the obscenely expensive
Hensley) make the pivot point seem to be at/near the rear axle like a
fifth wheel setup.

Will Sill
The Curmudgeon of Sill Hill

+++++++++++++++++++++++++++++++++++

AllI can say Will, darling, is that you can show me your drawbar and
hitch ball anytime big boy. I think you are such a sexy fox! I'm
soooooooooooooooo hot for you and drool over every word you utter on
Usenet. Bye sweetie...

-RV Mama

Drawbar Length - How Long?
 

Dave Lee wrote:
I assume the weight distribution of the boats differ, in that an outboard,
or I/O board has significant weight in the ass end for the engine, wheras
the sailboat would be different.

Of course! That should have occurred to me.

Ken

Drawbar Length - How Long?
 

"JerryD\(upstateNY\)" wrote in
:

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.


Hm.. I would have thought the opposite.
A longer tongue length inceases the cantalever leverage.
Therefore since the Sailboat does not have a heavy motor over the wheels,
or hanging off the back (if it was an outboard), you are now carrying more
weight in front of the axle making for a heavier tongue.
Extend the length out to increase the leverage and reduce the tongue
loading?