trailer sway mitigation TSM

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.

wrote on 12/21/2019 6:39 AM:
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.

The steel belted radial was well-established in 1987. I've discussed tires,
particularly trailer tires, with Nelson many times since then, including recently
about the specific tires to get for my trailer. He has never mentioned any changes
to tire technology that would affect us, nor have I heard of anything.

Also, there is nothing in his paper that depends directly on tire technology. It's
the lateral stiffness of the tire tread that is important; then and now, radial
tires have significantly more stiffness that a comparable bias ply tire.

--
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 Saturday, December 21, 2019 at 7:56:08 AM UTC-8, Eric Greenwell wrote:
wrote on 12/21/2019 6:39 AM:
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.

The steel belted radial was well-established in 1987. I've discussed tires,
particularly trailer tires, with Nelson many times since then, including recently
about the specific tires to get for my trailer. He has never mentioned any changes
to tire technology that would affect us, nor have I heard of anything.

Also, there is nothing in his paper that depends directly on tire technology. It's
the lateral stiffness of the tire tread that is important; then and now, radial
tires have significantly more stiffness that a comparable bias ply tire.

--
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

Light truck tires are not available in a size that fits Cobra trailers. Found that out this last summer when I had to replace a blown tire.

Tom

On Saturday, December 21, 2019 at 5:51:26 PM UTC-8, 2G wrote:
On Saturday, December 21, 2019 at 7:56:08 AM UTC-8, Eric Greenwell wrote:
wrote on 12/21/2019 6:39 AM:
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.

The steel belted radial was well-established in 1987. I've discussed tires,
particularly trailer tires, with Nelson many times since then, including recently
about the specific tires to get for my trailer. He has never mentioned any changes
to tire technology that would affect us, nor have I heard of anything.

Also, there is nothing in his paper that depends directly on tire technology. It's
the lateral stiffness of the tire tread that is important; then and now, radial
tires have significantly more stiffness that a comparable bias ply tire..

--
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

Light truck tires are not available in a size that fits Cobra trailers. Found that out this last summer when I had to replace a blown tire.

Tom

The curious thing in the LT vs ST debate is WHY would a tire company design a BETTER trailer tire intended to be put on a truck than a tire SPECIFICALLY and EXCLUSIVELY to be used on trailers? Just doesn't make any sense. Note that is a different question as to is it ok to use an LT tire on a trailer.

2G wrote on 12/21/2019 6:23 PM:
On Saturday, December 21, 2019 at 5:51:26 PM UTC-8, 2G wrote:
Light truck tires are not available in a size that fits Cobra trailers. Found that out this last summer when I had to replace a blown tire.

Tom

The curious thing in the LT vs ST debate is WHY would a tire company design a BETTER trailer tire intended to be put on a truck than a tire SPECIFICALLY and EXCLUSIVELY to be used on trailers? Just doesn't make any sense. Note that is a different question as to is it ok to use an LT tire on a trailer.

LT tires make fine trailer tires; after all, they can handle the more demanding
life on a truck. But! They cost more - often much more - than a trailer tire, due
in part to the much higher speed rating, and that's why the tire companies make
trailer tires. Who would buy a $124 LT tire when they can get an ST tire for $80?

--
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

2G wrote on 12/21/2019 5:51 PM:
On Saturday, December 21, 2019 at 7:56:08 AM UTC-8, Eric Greenwell wrote:
wrote on 12/21/2019 6:39 AM:
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.

The steel belted radial was well-established in 1987. I've discussed tires,
particularly trailer tires, with Nelson many times since then, including recently
about the specific tires to get for my trailer. He has never mentioned any changes
to tire technology that would affect us, nor have I heard of anything.

Also, there is nothing in his paper that depends directly on tire technology. It's
the lateral stiffness of the tire tread that is important; then and now, radial
tires have significantly more stiffness that a comparable bias ply tire.



Light truck tires are not available in a size that fits Cobra trailers. Found that out this last summer when I had to replace a blown tire.

Yokohama Supervan Y356 LT195/75R14 fit my ASH 26 E trailer. I got them from
Tirerack.com, and they still carry them. Walmart has them, too, but you might have
to order them first if you want to pick them up locally.

--
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 Friday, December 20, 2019 at 11:56:12 PM UTC-5, Eric Greenwell wrote:
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

Hi Eric,

Thanks for your reply. I hear you and accept what you say.

Many sources out there on the www (wild, wild web) with advice on trailer towing say that bias-ply tires have stiffer sidewalls and reduce trailer sway--just one example being https://www.westmarine.com/WestAdvis...er-Tire-Basics. Not arguing, just sayin'.

I am be interested in reading your test results. Please email at iandotgrant12atgmaildotcom

Many thanks!
IN

On Friday, December 20, 2019 at 11:56:12 PM UTC-5, Eric Greenwell wrote:
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

Hi Eric,

Thanks for your reply. I hear you and accept what you say.

Many sources out there on the www (wild, wild web) with advice on trailer towing say that bias-ply tires have stiffer sidewalls and reduce trailer sway--just one example being https://www.westmarine.com/WestAdvis...er-Tire-Basics. Not arguing, just sayin'.

I am interested in reading your test results. Please email me at iandotgrant12atgmaildotcom

Many thanks!
IN