glider trailer tires

[Ken Ward]

what's the story on tires? is it OK to use regular automotive radial
tires or are ST tires required?

thanks,
Ken

[[email protected]]

Ken Ward wrote:
> what's the story on tires? is it OK to use regular automotive radial
> tires or are ST tires required?
>
> thanks,
> Ken

Use the heavist duty tires that will fit your rims (or get bigger
rims). There is something about trailer duty that is hard on tires.
Myself and several friends have had tire blow-outs in recent years on
tires that should have been ok. It might be the (slight) fish-tailing
that you see on all trailers in tow is extra hard on the side walls,
but I really don't know for sure. I am refering to single axle trailers
(no experience with dual axle).

Tom Seim
2G
Richland, WA

[[email protected]]

Trailer tires are preferred, especially on single axels, trailer tires
have heavier built side walls and withstand side torque better.


wrote:
> Ken Ward wrote:
> > what's the story on tires? is it OK to use regular automotive radial
> > tires or are ST tires required?
> >
> > thanks,
> > Ken
>
> Use the heavist duty tires that will fit your rims (or get bigger
> rims). There is something about trailer duty that is hard on tires.
> Myself and several friends have had tire blow-outs in recent years on
> tires that should have been ok. It might be the (slight) fish-tailing
> that you see on all trailers in tow is extra hard on the side walls,
> but I really don't know for sure. I am refering to single axle trailers
> (no experience with dual axle).
>
> Tom Seim
> 2G
> Richland, WA

[01-- Zero One]

Ken,



Check the archives on RAS. This has come up several times over the past
several years and there is some very good discussion in there.



Larry

"01" USA





"Ken Ward" > wrote in message
:

> what's the story on tires? is it OK to use regular automotive radial
> tires or are ST tires required?
>
> thanks,
> Ken

[[email protected]]

Ken Ward wrote:
> what's the story on tires? is it OK to use regular automotive radial
> tires or are ST tires required?
>
> thanks,
> Ken

Almost no trailer loads a tire as much as a car.
That said- a couple things to consider-
A slightly lower profile tire can go a long way toward reducing
sidewall flex which does feed back to the towing vehicle as sway. Paul
Cordell found some cool inexpensive wheels for his Cobra trailer that
were larger in diameter allowing low profile tires and retaining ride
height.
MOST IMPORTANT- A not well know fact is that materials of tire
construction have changed and the usefull safe life is less due to
aging affects. Car manufacturers now specify replacement after 5 years.
This is mostly due to changes made to get long wear life and better
fuel economy.
The bottom line is it probably less important what you change to than
that you change.
Good luck UH

[Ray Lovinggood]

Whether it is a $10,000 HP or a $100,000+ ASG/DG/LS/S-H/Antares/wh
atever, I think I would err on the side of the 'ST'
tire. It's precious cargo back there and I don't want
to 'skimp' on the tire. Sure, I might get a car tire
for $30 or $40 vs. the 'ST' for $80 or $90, but I still
go back to thinking about the cargo I'm hauling. And
in the case of a nice trailer, the cargo and the trailer
itself!

The last time I bought tires for my homebuilt trailer,
I bought the 'ST' tires from Goodyear. Now I have
new trailer and when the five or six years have come
and gone, I'll put 'ST' tires on it. Sway was not
a problem with the old ugly homebuilt (it towed extremely
easily) and it isn't a problem with the factory trailer.
It too tows well, both empty and loaded, behind a
Honda Accord V6.

Amazing that we can drop thousands of dollars (or whatever
currency) on instruments and gel coats and winglets
and fuzzy dice or whatever, but we want to skimp on
the trailer tires.

Ray Lovinggood
Carrboro, North Carolina, USA


At 12:48 27 September 2006,
wrote:
>
>Ken Ward wrote:
>> what's the story on tires? is it OK to use regular
>>automotive radial
>> tires or are ST tires required?
>>
>> thanks,
>> Ken
>
>Almost no trailer loads a tire as much as a car.
>That said- a couple things to consider-
>A slightly lower profile tire can go a long way toward
>reducing
>sidewall flex which does feed back to the towing vehicle
>as sway. Paul
>Cordell found some cool inexpensive wheels for his
>Cobra trailer that
>were larger in diameter allowing low profile tires
>and retaining ride
>height.
>MOST IMPORTANT- A not well know fact is that materials
>of tire
>construction have changed and the usefull safe life
>is less due to
>aging affects. Car manufacturers now specify replacement
>after 5 years.
>This is mostly due to changes made to get long wear
>life and better
>fuel economy.
>The bottom line is it probably less important what
>you change to than
>that you change.
>Good luck UH
>
>

[Ray Lovinggood]

Whether it is a $10,000 HP or a $100,000+ ASG/DG/LS/S-H/Antares/wh
atever, I think I would err on the side of the 'ST'
tire. It's precious cargo back there and I don't want
to 'skimp' on the tire. Sure, I might get a car tire
for $30 or $40 vs. the 'ST' for $80 or $90, but I still
go back to thinking about the cargo I'm hauling. And
in the case of a nice trailer, the cargo and the trailer
itself!

The last time I bought tires for my homebuilt trailer,
I bought the 'ST' tires from Goodyear. Now I have
new trailer and when the five or six years have come
and gone, I'll put 'ST' tires on it. Sway was not
a problem with the old ugly homebuilt (it towed extremely
easily) and it isn't a problem with the factory trailer.
It too tows well, both empty and loaded, behind a
Honda Accord V6.

Amazing that we can drop thousands of dollars (or whatever
currency) on instruments and gel coats and winglets
and fuzzy dice or whatever, but we want to skimp on
the trailer tires.

Ray Lovinggood
Carrboro, North Carolina, USA


At 12:48 27 September 2006,
wrote:
>
>Ken Ward wrote:
>> what's the story on tires? is it OK to use regular
>>automotive radial
>> tires or are ST tires required?
>>
>> thanks,
>> Ken
>
>Almost no trailer loads a tire as much as a car.
>That said- a couple things to consider-
>A slightly lower profile tire can go a long way toward
>reducing
>sidewall flex which does feed back to the towing vehicle
>as sway. Paul
>Cordell found some cool inexpensive wheels for his
>Cobra trailer that
>were larger in diameter allowing low profile tires
>and retaining ride
>height.
>MOST IMPORTANT- A not well know fact is that materials
>of tire
>construction have changed and the usefull safe life
>is less due to
>aging affects. Car manufacturers now specify replacement
>after 5 years.
>This is mostly due to changes made to get long wear
>life and better
>fuel economy.
>The bottom line is it probably less important what
>you change to than
>that you change.
>Good luck UH
>
>

[Cliff Hilty]

Directly from Dicount Tier web page:

http://www.discounttire.com/dtcs/infoTrailerTireFacts.dos

Trailer Tire Applications
Trailer tires are designed for use on trailer axle
positions only, not for the loads applied to or the
traction required by drive or steering axles.
An 'LT' designation on a trailer tire size specifies
load range only. It is not designed for use on light
trucks.
Do not mount 'ST' or 'LT' trailer tires on passenger
cars or light trucks.
Inflation
Always inflate trailer tires to the maximum inflation
indicated on the sidewall.
Check inflation when the tires are cool and have not
been exposed to the sun.
If the tires are hot to the touch from operation, add
3 psi to the max inflation.
Underinflation is the number 1 cause of trailer tire
failure.
Load Carrying Capacity
All tires must be identical in size for the tires to
properly manage the weight of the trailer.
The combined capacity of the tires must equal or exceed
the GVW of the axle.
The combined capacity of all of the tires should exceed
the loaded trailer weight by 20 percent.
If the actual weight is not available, use the trailer
GVW. If a tire fails on a tandem axle trailer, you
should replace both tires on that side. The remaining
tire was likely subjected to excessive loading.
If the tires are replaced with tires of larger diameter,
the tongue height may need to be adjusted to maintain
proper weight distribution.
Speed
All 'ST' tires have a maximum speed rating of 65 mph.

As heat builds up, the tire's structure starts to disintegrate
and weaken.
The load carrying capacity gradually decreases as the
heat and stresses generated by higher speed increases.

Time
Time and the elements weaken a trailer tire.
In about 3 years roughly one third of the tire's strength
is gone.
Three to five years is the projected life of a normal
trailer tire.
It is suggested that trailer tires be replaced after
3 to 4 years of service regardless of tread depth or
tire appearance.
Mileage
Trailer tires are not designed to wear out.
The life of a trailer tire is limited by time and duty
cycles.
The mileage expectation of a trailer tire would be
5,000 to 12,000 miles.
Why Use An 'ST' Tire
'ST' tires feature materials and construction to meet
the higher load requirements and demands of trailering.

The polyester cords are bigger than they would be for
a comparable 'P' or 'LT' tire.
The steel cords have a larger diameter and greater
tensile strength to meet the additional load requirements.

'ST' tire rubber compounds contain more chemicals to
resist weather and ozone cracking.
Storage
The ideal storage is in a cool, dark garage at maximum
inflation.
Use tire covers to protect the tires from direct sunlight.

Use thin plywood sections between the tire and the
pavement.
For long term storage: Put the trailer on blocks to
take the weight off the tires, lower the air pressure
and cover tires to protect from direct sunlight.
Maintenance
Clean the tires using mild soap and water.
Do not use tire-care products containing alcohol or
petroleum distillates.
Inspect for any cuts, snags, bulges or punctures.
Check the inflation before towing and again before
the return trip.
Three Keys to Avoiding Trouble
Make sure your rig is equipped with the proper tires.

Maintain the tires meticulously.
Replace trailer tires every three to five years, whether
they look like they're worn out or not.

[Eric Greenwell]

wrote:
> Ken Ward wrote:
>> what's the story on tires? is it OK to use regular automotive radial
>> tires or are ST tires required?

Ken, what trailer do you have, what tires are on it now, and is the
towing stability satisfacory?

> Almost no trailer loads a tire as much as a car.

This might lead the unwary to think they can get by with a lesser tire
than they could on their car, yet glider trailers seem to suffer far
more tread separations than cars do (mile for mile). You need to match
the tire to the load, and trailer tires are rated differently than car
tires. Generally, passenger car tires need to be derated about 10% from
their load rating to be equivalent to a trailer tire rating.

> That said- a couple things to consider-
> A slightly lower profile tire can go a long way toward reducing
> sidewall flex which does feed back to the towing vehicle as sway. Paul
> Cordell found some cool inexpensive wheels for his Cobra trailer that
> were larger in diameter allowing low profile tires and retaining ride
> height.

It's not sidewall flex that's the important factor, but "lateral slip
stiffness", but enough of the technobabble - it's not something you can
read on the tire spec sheet in any case. Lower profiles tend to have
this, as do higher speed ratings. So, if stability was an issue, going
to a lower profile and higher speed rating will help. Lower profile
tires tend to ride harder, and may be more susceptible to impact damage
from potholes, road hazards, and things like curbs, so they should be
checked more often.

Speaking of speed, ST tires are rated for 65 mph, unless you run them at
a much higher pressure than the load rating tables show. Be careful if
you plan to tow at 65+ with an ST rated tire. For towing above 65, I'd
use a high speed rated tire instead of an ST tire, and (somewhat
arbitrarily) pick one rated for at least 20 mph higher than I intended
to tow.

> MOST IMPORTANT- A not well know fact is that materials of tire
> construction have changed and the usefull safe life is less due to
> aging affects. Car manufacturers now specify replacement after 5 years.
> This is mostly due to changes made to get long wear life and better
> fuel economy.
> The bottom line is it probably less important what you change to than
> that you change.

Indeed.


--
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[[email protected]]

In the USA I have had good luck buying my trailer tires from:
www.tirerack.com

They ship same or next day and you get them installed locally for
cheap. You get exactly what you want every time. I think I paid $58
each for Goodyear Marathon trailer tires last time. Not more than I
would expect to pay for auto/LT tires if bought from a shop.

I always change my trailer tires after 3 years of use no matter how
they look. It's not worth the risk of a blowout to take them much
beyond that.

Pat Russette
CQ

[Ken Ward]

What I found is that a previous owner used 165R15 tires (common
automotive radial tires). These tires sidewalls were bulging and
cracking in an ugly fashion. With the help of a trailer shop we
realized that the rims should have something like a 205D15 ST or a
ST205/75D-15 tire, which I got today.

When I started to put them on the drums, I found out why the previous
tires were the smaller diameter automotive tires; fender clearance.
They will clear the inside of the fender, but only under no-load
conditions. As soon as I took the jack stand out and lowered the axle,
the tire is nearly rubbing inside the fender. Any bouncing and it's
going to chirp.

Rather than go back to the smaller incorrect tires, I'm going to take a
Sawzall to the fender mounts tomorrow, and remove the fenders. I'm
going to figure out where the fender really should be mounted, add a
little clearance, then get the fenders welded back on.

Judging from the spare, I think the trailer originally come with three
6.00x15 tires. These will fit in the fender space, but are no longer
available. The date stamp on the spare is 1988.

Thanks to everyone for the advice to get the right tires!

Ken

PS: while I had the wheels off I checked the axle bearings and the
bearings in the drums; all are good. that's more than I can say about
the brakes, which are nasty. I'm going to completely replace the brake
backing plates with a new plate which has fresh slave cylinders and
brake shoes. I used a micrometer on the drums today and if I have them
turned 0.010", they'll be at the discard limit. I probably need a new
Atwood master cylinder on the tongue as well, or at least a rebuild.

In article . com>,
" > wrote:

> Trailer tires are preferred, especially on single axels, trailer tires
> have heavier built side walls and withstand side torque better.
>
>
> wrote:
> > Ken Ward wrote:
> > > what's the story on tires? is it OK to use regular automotive radial
> > > tires or are ST tires required?
> > >
> > > thanks,
> > > Ken
> >
> > Use the heavist duty tires that will fit your rims (or get bigger
> > rims). There is something about trailer duty that is hard on tires.
> > Myself and several friends have had tire blow-outs in recent years on
> > tires that should have been ok. It might be the (slight) fish-tailing
> > that you see on all trailers in tow is extra hard on the side walls,
> > but I really don't know for sure. I am refering to single axle trailers
> > (no experience with dual axle).
> >
> > Tom Seim
> > 2G
> > Richland, WA

[Papa3]

Ken Ward wrote:
> >
> Rather than go back to the smaller incorrect tires, I'm going to take a
> Sawzall to the fender mounts tomorrow, and remove the fenders. I'm
> going to figure out where the fender really should be mounted, add a
> little clearance, then get the fenders welded back on.
>
>
>
> Ken
>
Ken,

Just a thought. I've seen several people go to the trouble of raising
the trailer slightly by putting in a spacer (steel I or C section)
between the axle and the trailer floor. This has the beneficial
effect of increasing clearance at the back end to avoid bottoming out
when crossing depressions (as well as taking care of your fender
clearance issue). It does require a little more effort (perhaps) than
remounting the fenders, but it may make some sense depending on the
type of trailer you have. I've seen this done very nicely on an older
Cobra trailer housing a Ventus.

P3

[jb92563]

Ken Ward wrote:
> what's the story on tires? is it OK to use regular automotive radial
> tires or are ST tires required?

Trailer tires should be the non-steel belted variety, because these
other nylon? belts withstand the excessive side loading better and do
not cause the belt to come out of the sidewall of tires like the steel
belted car tires will.

Also since the trailer frequently sits in one position on the tire for
long periods, it can cause a deformation in the steel belted variety
that the non-metal belted variety are more resistant to.

Bigger tires = less rotations for a given distance which also save wear
and tear on the rubber and more importantly, the bearings.

Be sure your bearings are good before long trips.....I had to replace
an entire axle/bearing/tire assembly on my tow from St Pete's FL to
Riverside, CA.....3500 miles (picking up a Monerai glider).

Unfortunately my right side bearing died a hundred feet from a Welcome
Center in Louisiana about 3 miles from a trailer repair
place.......lucky me...I decided to replace the entire axle/bearings
assembly(Champion Trailers) and a pair of Walmart trailer tire/rims for
under $250 and about 4 hours of driving, waiting and replacement work
at the rest stop......and the rain held off until I had time to put
everything away and get cleaned up......more lucky!

Ray

[Big John]

Ken

Will use your posting to add a comment on trailers.

My SIL and daughter have a medium length TT and use a "Hensley" hitch
(well know in the Travel Trailer Comunity). They experience no fish
tailing with that hitch at any speed or weather conditions.

Costs a little more than a ball and socket but safety towing makes it
worth while.

There is a cheaper rip off of design also on the market but I'm not
sure how well it works?


Big John
USAF Heavy Iron Driver but looking at gliders :o)
`````````````````````````````````````````````````` `````````````````````


On Mon, 25 Sep 2006 18:58:57 GMT, Ken Ward >
wrote:

>what's the story on tires? is it OK to use regular automotive radial
>tires or are ST tires required?
>
>thanks,
>Ken

[Eric Greenwell]

jb92563 wrote:
> Ken Ward wrote:
>> what's the story on tires? is it OK to use regular automotive radial
>> tires or are ST tires required?
>
> Trailer tires should be the non-steel belted variety, because these
> other nylon? belts withstand the excessive side loading better and do
> not cause the belt to come out of the sidewall of tires like the steel
> belted car tires will.
>
> Also since the trailer frequently sits in one position on the tire for
> long periods, it can cause a deformation in the steel belted variety
> that the non-metal belted variety are more resistant to.

Do you have references for this deformation and advantages of non-metal
belts? It's such surprising information, I'd like to look into it further.

--
Eric Greenwell - Washington State, USA
Change "netto" to "net" to email me directly

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org

[[email protected]]

A few tips on tires and bearings from the big rig world:

At the start of any trip (within the first hour or so) stop and bring
the back of your hand close to the tire sidewall and the bearing caps.
If you feel excessive heat, identify and correct the problem before
continuing. Don't actually touch either; if they are failing, you will
burn your hand. For the rest of the trip, perform this check at every
fuel stop and/or the start of each day.

Check tire pressures at the start of each trip and at the start of each
day of the trip if it's a long one. Use a gauge for checking
pressures. It's impossible to tell if the pressures are right by
looking or by thumping. Perform these checks on both the tow vehicle
and the trailer. Everything that's been said in this thread about
underinflated trailer tires is true of the car/truck tires as well.

In addition to the potential for damage, underinflated tires decrease
fuel milage. If the tire pressures don't match closely, side to side,
the handling of the combination could be compromised. Over-inflation,
while usually not as dangerous as underinflation, can cause tires to
wear more quickly at the center of the tread, compromise braking, and
pound the cargo.

Tighten the valve stem cores periodically and be sure to use valve stem
caps to reduce deterioration of the seals due to oxidation. When
replacing tires, be sure that the valve stems are replaced as well.
Some shops will try to save time by reusing them.

Ray Warshaw
1LK







Cliff Hilty wrote:
> Directly from Dicount Tier web page:
>
> http://www.discounttire.com/dtcs/infoTrailerTireFacts.dos
>
> Trailer Tire Applications
> Trailer tires are designed for use on trailer axle
> positions only, not for the loads applied to or the
> traction required by drive or steering axles.
> An 'LT' designation on a trailer tire size specifies
> load range only. It is not designed for use on light
> trucks.
> Do not mount 'ST' or 'LT' trailer tires on passenger
> cars or light trucks.
> Inflation
> Always inflate trailer tires to the maximum inflation
> indicated on the sidewall.
> Check inflation when the tires are cool and have not
> been exposed to the sun.
> If the tires are hot to the touch from operation, add
> 3 psi to the max inflation.
> Underinflation is the number 1 cause of trailer tire
> failure.
> Load Carrying Capacity
> All tires must be identical in size for the tires to
> properly manage the weight of the trailer.
> The combined capacity of the tires must equal or exceed
> the GVW of the axle.
> The combined capacity of all of the tires should exceed
> the loaded trailer weight by 20 percent.
> If the actual weight is not available, use the trailer
> GVW. If a tire fails on a tandem axle trailer, you
> should replace both tires on that side. The remaining
> tire was likely subjected to excessive loading.
> If the tires are replaced with tires of larger diameter,
> the tongue height may need to be adjusted to maintain
> proper weight distribution.
> Speed
> All 'ST' tires have a maximum speed rating of 65 mph.
>
> As heat builds up, the tire's structure starts to disintegrate
> and weaken.
> The load carrying capacity gradually decreases as the
> heat and stresses generated by higher speed increases.
>
> Time
> Time and the elements weaken a trailer tire.
> In about 3 years roughly one third of the tire's strength
> is gone.
> Three to five years is the projected life of a normal
> trailer tire.
> It is suggested that trailer tires be replaced after
> 3 to 4 years of service regardless of tread depth or
> tire appearance.
> Mileage
> Trailer tires are not designed to wear out.
> The life of a trailer tire is limited by time and duty
> cycles.
> The mileage expectation of a trailer tire would be
> 5,000 to 12,000 miles.
> Why Use An 'ST' Tire
> 'ST' tires feature materials and construction to meet
> the higher load requirements and demands of trailering.
>
> The polyester cords are bigger than they would be for
> a comparable 'P' or 'LT' tire.
> The steel cords have a larger diameter and greater
> tensile strength to meet the additional load requirements.
>
> 'ST' tire rubber compounds contain more chemicals to
> resist weather and ozone cracking.
> Storage
> The ideal storage is in a cool, dark garage at maximum
> inflation.
> Use tire covers to protect the tires from direct sunlight.
>
> Use thin plywood sections between the tire and the
> pavement.
> For long term storage: Put the trailer on blocks to
> take the weight off the tires, lower the air pressure
> and cover tires to protect from direct sunlight.
> Maintenance
> Clean the tires using mild soap and water.
> Do not use tire-care products containing alcohol or
> petroleum distillates.
> Inspect for any cuts, snags, bulges or punctures.
> Check the inflation before towing and again before
> the return trip.
> Three Keys to Avoiding Trouble
> Make sure your rig is equipped with the proper tires.
>
> Maintain the tires meticulously.
> Replace trailer tires every three to five years, whether
> they look like they're worn out or not.

[jb92563]

Check out these articles:

http://www.advanceautoparts.com/english/youcan/html/ccr/ccr20040501tt.html

http://www.championtrailers.com/tire_art.html

Basically you need ST tires of the Bias variety for a glider trailer:

The Bias and Bias Belted (nylon) tires give you better sway and load
control, where radial
gives you longer treadlife and more flexible sidewalls(less sway
resistance).

The radials with weaker sidewalls sway more, and eventually all that
sidewall flexing could cause steel belt fractures, once fractures the
belts migrate out through the sidewall weakening it further and
contributing to a sidewall blowout.

Generally people keep radials far to long since they last longer in
terms of tread wear, but to risk your glider and trailer, and perhaps
much more is not wise.

As far as the material memory.....try this test.....deflate your
radials and let them sit for a year.......now inflate them and take the
trailer for a spin......that horible bouncing drive down the road is
due to bent steel in your steel belted tires.....sure it will smooth
out after a while, but its because the belts are broken now and after a
while you will notice steel wire exiting your tire sidewall.

Do the same with nylon tires and you wont even notice anything and the
integrity of the tire is maintained through out the exercise because
nothing actually broke internally.

(More simply....bend some nylon (comb?) a bit and release...how long
before it straightens out on its own?....now try with a peice of
steel...how long for the steel to straighten on its own?......theres
the POINT!)

Im frankly amazed that this is not common knowledge about the Bias
tires being best for glider trailers because of the way we treat our
trailers, leaving them alone, deflated and neglected frequently !

Ray

[jb92563]

Check out these articles:

http://www.advanceautoparts.com/english/youcan/html/ccr/ccr20040501tt.html

http://www.championtrailers.com/tire_art.html

Basically you need ST tires of the Bias variety for a glider trailer:

The Bias and Bias Belted (nylon) tires give you better sway and load
control, where radial
gives you longer treadlife and more flexible sidewalls(less sway
resistance).

The radials with weaker sidewalls sway more, and eventually all that
sidewall flexing could cause steel belt fractures, once fractures the
belts migrate out through the sidewall weakening it further and
contributing to a sidewall blowout.

Generally people keep radials far to long since they last longer in
terms of tread wear, but to risk your glider and trailer, and perhaps
much more is not wise.

As far as the material memory.....try this test.....deflate your
radials and let them sit for a year.......now inflate them and take the
trailer for a spin......that horible bouncing drive down the road is
due to bent steel in your steel belted tires.....sure it will smooth
out after a while, but its because the belts are broken now and after a
while you will notice steel wire exiting your tire sidewall.

Do the same with nylon tires and you wont even notice anything and the
integrity of the tire is maintained through out the exercise because
nothing actually broke internally.

(More simply....bend some nylon (comb?) a bit and release...how long
before it straightens out on its own?....now try with a peice of
steel...how long for the steel to straighten on its own?......theres
the POINT!)

Im frankly amazed that this is not common knowledge about the Bias
tires being best for glider trailers because of the way we treat our
trailers, leaving them alone an neglected frequently !

Ray

[Eric Greenwell]

jb92563 wrote:
> Check out these articles:
>
> http://www.advanceautoparts.com/english/youcan/html/ccr/ccr20040501tt.html
>
>
> http://www.championtrailers.com/tire_art.html
>
> Basically you need ST tires of the Bias variety for a glider trailer:
>
>
> The Bias and Bias Belted (nylon) tires give you better sway and load
> control, where radial gives you longer treadlife and more flexible
> sidewalls(less sway resistance).

I read the articles, but I'm very skeptical. When I go to an RV show
and look at tires on the travel trailers and 5th wheels, they all have
radials on them. Ditto for when I go to a boat show and look at the
tires on the boat trailers.

The other thing I notice is a major tire company like Goodyear offers
only radial ST tires, for example, either steel/steel or steel/fabric
construction. If radial ST tires are such a poor choice, and the fact
that they are more expensive, it sure makes me wonder why they are so
popular.

Here's a quote from a 2002 Trailer life article (http://tinyurl.com/9jesg):

> Trailer-tire sidewall stiffness is a compromise between P and LT
> designs. The desire for stiffer sidewalls is still occasionally cited
> as the reason for choosing a bias-belted trailer tire. While
> passenger-car tires are nearly all radials these days, ST tires are
> still available in bias-belted construction. Radial trailer tires are
> superior in all respects to bias-belted tires except in sidewall
> stiffness. Reduced tire heat, lower rolling resistance and softer
> ride are among the benefits of radials, not to mention extended wear.

It doesn't sound like they share your concerns about radial ST tires.
Steel belted radials also have superior impact resistance compared to
tires with fabric belts.

> The radials with weaker sidewalls sway more, and eventually all that
> sidewall flexing could cause steel belt fractures, once fractures the
> belts migrate out through the sidewall weakening it further and
> contributing to a sidewall blowout.
>
> Generally people keep radials far to long since they last longer in
> terms of tread wear, but to risk your glider and trailer, and perhaps
> much more is not wise.

I agree with this, because I know a lot of pilots keep their tires
(radial or not) too long, because they are going tread depth instead of
age.

>
> As far as the material memory.....try this test.....deflate your
> radials and let them sit for a year.......now inflate them and take
> the trailer for a spin......that horible bouncing drive down the road
> is due to bent steel in your steel belted tires.....sure it will
> smooth out after a while, but its because the belts are broken now
> and after a while you will notice steel wire exiting your tire
> sidewall.
>
> Do the same with nylon tires and you wont even notice anything and
> the integrity of the tire is maintained through out the exercise
> because nothing actually broke internally.

Deflating ANY tire and letting the load sit on it for a year is very bad
practice. It's irrelevant whether steel or fabric tires are better at
it. It's dangerous - toss the tires, regardless of type, if it happens
to you.

>
> (More simply....bend some nylon (comb?) a bit and release...how long
> before it straightens out on its own?....now try with a peice of
> steel...how long for the steel to straighten on its own?......theres
> the POINT!)

I tried that with a nylon comb and a steel cable like they use in tires.
Gosh, the cable straightened right out and comb didn't! This is a
worthless test.

Besides, don't you remember how badly nylon tires use to thump when
you'd first drive off? It's because nylon takes a "set" very easily, and
that is why polyester and steel are the popular materials for tires for
the last few decades. They don't take a set.
>
> Im frankly amazed that this is not common knowledge about the Bias
> tires being best for glider trailers because of the way we treat our
> trailers, leaving them alone, deflated and neglected frequently !

I believe the main advantage of a bias ply tire is it's lower cost.

--
Eric Greenwell - Washington State, USA
Change "netto" to "net" to email me directly

"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html

"A Guide to Self-launching Sailplane Operation" at www.motorglider.org