trailer sway mitigation TSM

On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
Look out when moving trailer weight forward... Never exceed the maximum tongue weight!
Jim

Also tighten up the hitch in the receiver with one of these: they take out the slop that can add to sway, and quiet down the rig

Maximum allowed tire pressure in trailer and rear tow vehicle axle.

On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
Look out when moving trailer weight forward... Never exceed the maximum tongue weight!
Jim

Also tighten up the hitch in the receiver with one of these: they take out the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway problems.

On Tuesday, December 17, 2019 at 10:15:29 AM UTC-7, Jonathan St. Cloud wrote:
On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
I have used three different model year Jeep Grand Cherokees as tow cars for over 35 years. Nelson Funston (JN) is a tire and trailer expert with big heavy trailers. With my first Jeep, told me to do three things in following order:
-Move some weight forward,-stiffer sidewall trailer tires at max pressure, -vehicle tires at max pressure. Ancillary advice, maintain Jeep shocks... We have some interstate speeds of 80 mph in Idaho. No sway!! All my Jeeps were the 8cyl model so heavier than the old 4cyl and most currently available 6cly on the road. Also all had 4 wheel drive and the off road accessory that has different suspension and road clearance. Boise Pilot




Look out when moving trailer weight forward... Never exceed the maximum tongue weight!
Jim

Also tighten up the hitch in the receiver with one of these: they take out the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway problems.

Boise Pilot wrote on 12/17/2019 10:19 AM:
On Tuesday, December 17, 2019 at 10:15:29 AM UTC-7, Jonathan St. Cloud wrote:
On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
I have used three different model year Jeep Grand Cherokees as tow cars for
over 35 years. Nelson Funston (JN) is a tire and trailer expert with big heavy
trailers. With my first Jeep, told me to do three things in following order:
-Move some weight forward,-stiffer sidewall trailer tires at max pressure,
-vehicle tires at max pressure. Ancillary advice, maintain Jeep shocks... We
have some interstate speeds of 80 mph in Idaho. No sway!! All my Jeeps were
the 8cyl model so heavier than the old 4cyl and most currently available 6cly
on the road. Also all had 4 wheel drive and the off road accessory that has
different suspension and road clearance. Boise Pilot




Look out when moving trailer weight forward... Never exceed the maximum
tongue weight! Jim

Also tighten up the hitch in the receiver with one of these: they take out
the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway
problems.

Anyone that wants to hear more from Nelson Funston can download his OSTIV paper on
trailer stability he

http://journals.sfu.ca/ts/index.php/...wnload/779/737

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Tuesday, December 17, 2019 at 2:01:56 PM UTC-5, Eric Greenwell wrote:
Boise Pilot wrote on 12/17/2019 10:19 AM:
On Tuesday, December 17, 2019 at 10:15:29 AM UTC-7, Jonathan St. Cloud wrote:
On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
I have used three different model year Jeep Grand Cherokees as tow cars for
over 35 years. Nelson Funston (JN) is a tire and trailer expert with big heavy
trailers. With my first Jeep, told me to do three things in following order:
-Move some weight forward,-stiffer sidewall trailer tires at max pressure,
-vehicle tires at max pressure. Ancillary advice, maintain Jeep shocks... We
have some interstate speeds of 80 mph in Idaho. No sway!! All my Jeeps were
the 8cyl model so heavier than the old 4cyl and most currently available 6cly
on the road. Also all had 4 wheel drive and the off road accessory that has
different suspension and road clearance. Boise Pilot




Look out when moving trailer weight forward... Never exceed the maximum
tongue weight! Jim

Also tighten up the hitch in the receiver with one of these: they take out
the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway
problems.

Anyone that wants to hear more from Nelson Funston can download his OSTIV paper on
trailer stability he

http://journals.sfu.ca/ts/index.php/...wnload/779/737

Anybody convert that model to a nice Excel spreadsheet?

Dave Nadler wrote on 12/17/2019 11:30 AM:
On Tuesday, December 17, 2019 at 2:01:56 PM UTC-5, Eric Greenwell wrote:
Boise Pilot wrote on 12/17/2019 10:19 AM:
On Tuesday, December 17, 2019 at 10:15:29 AM UTC-7, Jonathan St. Cloud wrote:
On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
I have used three different model year Jeep Grand Cherokees as tow cars for
over 35 years. Nelson Funston (JN) is a tire and trailer expert with big heavy
trailers. With my first Jeep, told me to do three things in following order:
-Move some weight forward,-stiffer sidewall trailer tires at max pressure,
-vehicle tires at max pressure. Ancillary advice, maintain Jeep shocks... We
have some interstate speeds of 80 mph in Idaho. No sway!! All my Jeeps were
the 8cyl model so heavier than the old 4cyl and most currently available 6cly
on the road. Also all had 4 wheel drive and the off road accessory that has
different suspension and road clearance. Boise Pilot




Look out when moving trailer weight forward... Never exceed the maximum
tongue weight! Jim

Also tighten up the hitch in the receiver with one of these: they take out
the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway
problems.

Anyone that wants to hear more from Nelson Funston can download his OSTIV paper on
trailer stability he

http://journals.sfu.ca/ts/index.php/...wnload/779/737

Anybody convert that model to a nice Excel spreadsheet?

About 8 years ago, I talked to Nelson about using the code; problem was, it was
written in an old version of FORTRAN (IIRC) that hadn't been supported for a long
time, and he didn't know any way to easily ["easily" being the important word]
convert to something that was supported. I've sent you an email with his email
address, so you can discuss it with him. I'd like be able to run it, too.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

On Tuesday, December 17, 2019 at 2:01:56 PM UTC-5, Eric Greenwell wrote:
Boise Pilot wrote on 12/17/2019 10:19 AM:
On Tuesday, December 17, 2019 at 10:15:29 AM UTC-7, Jonathan St. Cloud wrote:
On Tuesday, December 17, 2019 at 8:06:29 AM UTC-8, Matt Herron Jr. wrote:
On Monday, December 16, 2019 at 4:43:23 PM UTC-8, JS wrote:
Good shocks seemed to have the biggest effect in my experience.
I have used three different model year Jeep Grand Cherokees as tow cars for
over 35 years. Nelson Funston (JN) is a tire and trailer expert with big heavy
trailers. With my first Jeep, told me to do three things in following order:
-Move some weight forward,-stiffer sidewall trailer tires at max pressure,
-vehicle tires at max pressure. Ancillary advice, maintain Jeep shocks... We
have some interstate speeds of 80 mph in Idaho. No sway!! All my Jeeps were
the 8cyl model so heavier than the old 4cyl and most currently available 6cly
on the road. Also all had 4 wheel drive and the off road accessory that has
different suspension and road clearance. Boise Pilot




Look out when moving trailer weight forward... Never exceed the maximum
tongue weight! Jim

Also tighten up the hitch in the receiver with one of these: they take out
the slop that can add to sway, and quiet down the rig

I found once I stopped towing with a Jeep Grand Cherokee I had no more sway
problems.

Anyone that wants to hear more from Nelson Funston can download his OSTIV paper on
trailer stability he

http://journals.sfu.ca/ts/index.php/...wnload/779/737

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...load-the-guide

Interesting paper, thanks for the link.

But I'm puzzled by Funston's remark at bottom of p34 that "Bias ply tires generally have 25 % io 30% lower lateral stiffness than radials and are not recommended for use on glider trailers".

Almost every other article I've seen on the web about trailer tires recommends the opposite: i.e. bias ply trailer tires (marked "D" on the sidewall) have stiffer sidewalls and cut down trailer sway.

What are others' opinions on bias vs radial trailer tires?

Ian "IN"

India November wrote on 12/20/2019 7:53 PM:
On Tuesday, December 17, 2019 at 2:01:56 PM UTC-5, Eric Greenwell wrote:

Anyone that wants to hear more from Nelson Funston can download his OSTIV paper on
trailer stability he

http://journals.sfu.ca/ts/index.php/...wnload/779/737

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...load-the-guide

Interesting paper, thanks for the link.

But I'm puzzled by Funston's remark at bottom of p34 that "Bias ply tires generally have 25 % io 30% lower lateral stiffness than radials and are not recommended for use on glider trailers".

Almost every other article I've seen on the web about trailer tires recommends the opposite: i.e. bias ply trailer tires (marked "D" on the sidewall) have stiffer sidewalls and cut down trailer sway.

What are others' opinions on bias vs radial trailer tires?

These claims are made by people that do not realize it is the tread stiffness
(resistance to lateral deflection) is the important factor in a tire's behavior.
The stiffer the tread, the smaller the slip angle, and small slip angles improve
vehicle stability.

https://suspensionsecrets.co.uk/tyre-slip-angle/

This is not opinion, but engineering fact. Instead of seeking opinions, I suggest
you look for facts; for example, look at tire company websites, tire
recommendations for things like travel trailers, or even wander about a RV trailer
lot, and note the radial tires on all the trailers. The only good feature of a
bias ply trailer tire is the lower price.

As a side note, bias ply trailer tires don't necessarily have the "stiffest"
sidewall (as measured by the "push" method). A few years ago, I measured that
stiffness on three similar sized tires, with the same load rating, for a glider
trailer. The stiffest was an LT (light truck tire), 2nd stiffest was the ST radial
tire, and least stiff was the ST bias ply tire. The LT tire was the most stable,
the ST bias ply tire was the least stable. I can send you a copy of the test
results if you want it.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Note that Nelson Funston's Trailer Dynamics paper was written in 1987. I would bet that tire technology has changed somewhat in the intervening 32 years. Still, the paper is interesting and informative.