Graham,
If the additional weight were so-called “sprung weight”, the issue you raise would be valid.  But, we’re talking about adding pieces/parts that are mostly unsprung weight, (i.e. not supported by the trailer’s springs).  The weight of the axles, most of the leaf springs, wheels, brakes, and tires is supported only by the tires.  Therefore, these pieces/parts do not contribute to tongue weight.  In the case of Slim’s trailer, adding the second axle behind the original axle caused a fraction of the total load to be taken up by the new axle.  In the case of tandem axles, you have calculate the position of an imaginary radius of pitch rotation, i.e. a point in space which defines the radius of the moment arm thru which the load is applied.  A rigorous calculation is quite involved; but, the approximate solution is midway between the two axles.  Since the radius moved aft, more of the load is carried forward of the radius, resulting in more tongue weight.

Roger Pihlaja
S/V Dynamic Equilibrium

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

From: Graham Stewart<mailto:gstewart8 at cogeco.ca>
Sent: Wednesday, May 19, 2021 9:33 AM
To: 'The Rhodes 22 Email List'<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Fwd: Trailer

Roger:
A technical question about adding an axel: I can see how moving the front axle forward so that the existing pivot point is midway between the axles would maintain the existing pivot point. However, you say that adding an axle to the trailer without moving the first axle would "move the pitch radius from the original center of the single axle back to ~ halfway between the centers of the tandem wheels". Is not adding the second axle and wheels also adding weight behind the pivot point thereby reducing the weight on the tongue? I am wondering how one would calculate where the new pivot point is in this scenario.

Graham Stewart
Agile, Rodes 22, 1976
Kingston Ontario

-----Original Message-----
From: Rhodes22-list [mailto:rhodes22-list-bounces at rhodes22.org] On Behalf Of ROGER PIHLAJA
Sent: Wednesday, May 19, 2021 8:26 AM
To: The Rhodes 22 Email List
Subject: Re: [Rhodes22-list] Fwd: Trailer

Slim,

So, your shop effectively moved the pitch radius from the original center of the single axle back to ~ halfway between the centers of the tandem wheels.  This will increase the tongue weight, fortunately in your case not enough to be dangerous.  I bet if you were to measure the tire loading, you would find your two front wheels are carrying considerable more load vs. the two back wheels.  Again, as long as you don’t exceed the tire load rating, this is not dangerous.  Have you noticed more tread wear on the front tires vs. the rear tires?  My four tires wear pretty evenly and I don’t rotate them or anything like that.  In fact, I tend to have to replace trailer tires most often due to cracking in the sidewalls due to oxygen and UV exposure after several years.  I have had a blowout and a steel wheel failure on my boat trailer in the 34 years I’ve owned it.  In both cases, I was extremely glad I had a tandem axle trailer!

Roger Pihlaja
S/V Dynamic Equilibrium

Sent from Mail<https://go.microsoft.com/fwlink/?LinkId=550986> for Windows 10

From: Steven Alm<mailto:stevenalm at gmail.com>
Sent: Tuesday, May 18, 2021 7:37 PM
To: The Rhodes 22 Email List<mailto:rhodes22-list at rhodes22.org>
Subject: Re: [Rhodes22-list] Fwd: Trailer

When I added the second axle to my trailer I did not reposition the first
axle. The second one was put on behind it. I did not do this work myself. I
checked with several  shops in my area until I found one who I felt would
do it right. They also fabricated new fenders over the wheels — single long
fenders covering both wheels. I don’t know what the tongue weight is but it
weighs down the back of the vehicle about two inches, so at least a couple
hundred pounds, probably more. They added electric breaks to the front
wheels and installed the controller up next to the steering column. In the
last 25 years  I’ve owned four different tow vehicles ranging from a 3/4
ton Ford E250 to a 6 cylinder Toyota 4Runner. All towed it fine without any
issues.

Slim
Fandango


On Tue, May 18, 2021 at 4:33 PM Jesse Shumaker <
jesse.laten.shumaker at gmail.com> wrote:

> I leave my Tohatsu 9.8 motor on the transom while trailering because it is
> heavy.  However, I take my rudder off and put that in the v-berth since
> that helps put more weight forward and takes stress off the transom.  I
> help support my motor with 3 separate straps that hang off the stern rail.
>
> My most recent process is to remove the tiller and connector to the motor
> so it's easy to handle the components rather than the whole assembly.  I
> had a cover made for the rudder so it's easy to maneuver through the cabin
> without scraping anything.  The cover is made such that I can put on and
> take it off while the rudder is mounted on the boat.
>
> The ramp at the lake where I sail is quite gradual so it's easy to get the
> boat far enough forward.  I'm still a novice when it comes to towing but
> haven't had any issues when towing around 60 MPH on my 2011 Triad single
> axle trailer.
>
> Jesse Shumaker
> S/V Zephyr
>
> On Wed, Apr 28, 2021 at 8:10 PM THOMAS POLISE via Rhodes22-list <
> rhodes22-list at rhodes22.org> wrote:
>
> > I have very little weight on my hitch and inquired to Triad trailer with
> > the response that I needed to remove motor.   Has anyone else had this
> > problem and resolved without having to take motor off?
> >
> >
> > Begin forwarded message:
> >
> > > From: Michael Orro <mike at triadtrailers.com>
> > > Date: April 28, 2021 at 3:16:51 PM EDT
> > > To: THOMAS POLISE <tvpolise at aol.com>
> > > Subject: RE: Polise trailer
> > >
> > > ?
> > > Hello Mr. Polise,
> > >
> > > Thank you for this information and for the measurements.   According to
> > the measurements, the trailer is built correctly.   I’ve attached a
> > photograph of a Rhodes 22 sitting on her Triad Trailer.   The boats
> appear
> > to be loaded in the same spot.  It looks like you have a motor hanging
> off
> > the back of the boat.  Do you?  If so, that motor needs to be loaded in
> the
> > boat as far forward as possible.   Other than this, I’m not sure what’s
> > going on.  I’m surprised they can’t move the boat a bit more forward on
> the
> > trailer.
> > >
> > > Best wishes,
> > > Mike Orro
> > > Triad Trailers LLC
> > > 5831 Triangle Drive
> > > Raleigh NC 27617
> > > Phone: 919.782.6007
> > > Fax: 919.782.6009
> > > email: Mike at TriadTrailers.com
> > > Web:  www.TriadTrailers.com<http://www.TriadTrailers.com<http://www.TriadTrailers.com%3chttp:/www.TriadTrailers.com>>
> > >
> > >
> > >
> > > From: THOMAS POLISE <tvpolise at aol.com>
> > > Sent: Wednesday, April 28, 2021 12:13 PM
> > > To: Michael Orro <mike at triadtrailers.com>
> > > Subject: Polise trailer
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
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