Trailer tires

In article f8aea33b-9947-4af8-9f65-092874f2dbb7
@x37g2000yqj.googlegroups.com, says...
Gang,

I'm leaving this Friday to pick up a glider that I purchased 1100
miles away. The trailer looks brand new, but is about 12 years old,
as are its tires. The glider and trailer weigh in the vicinity of 950
#. The tire spec from the owner is :
Carlisle Sure Trail ST
ST205/75014 (replaces F78-14ST)
Max Load 1760 lbs @ 50 PSI (actual load will be under 500 lbs)

I plan to buy 2 new tires before the trip, and stop at the first
service station after the pickup and have them mounted. Question is,
what to buy. It does not appear that the trailer has any suspension,
so I think I'd run the tires slightly soft, maybe 25-30 psi. I was
wondering about whether it should be radial or bias ply? Any
particular brands?

Thanks in advance,

If I were you I'd use LT tires (light truck), and run 'em at their rated
60psi (60-65 is about normal for LT tires (should be written on them,
often is)).

I'd also double-check the suspension, could in "in-axle" type, as is
popular in NZ - a Co. makes 'em here and call 'em Duro-torque (sp?).

--
Duncan

On Jan 20, 4:30*pm, Dave Doe wrote:

If I were you I'd use LT tires (light truck), and run 'em at their rated
60psi (60-65 is about normal for LT tires (should be written on them,
often is)).

The LTX tires on my van has a max pressure of 35 psi so be careful
what you select.

I ran radials at 35 psi on my Minden trailer and it was far better on
rough roads and uneven freeway pavement than my new Cobra which has
smaller wheels and higher pressure tires. I sometimes think getting
the heavy duty suspension was a mistake. It seems too stiff for the
trailer weight.

Andy

Andy wrote:
On Jan 20, 4:30 pm, Dave Doe wrote:

If I were you I'd use LT tires (light truck), and run 'em at their rated
60psi (60-65 is about normal for LT tires (should be written on them,
often is)).

The LTX tires on my van has a max pressure of 35 psi so be careful
what you select.

LTX is a Michelin designation, and does not mean it's an "LT" (Light
Truck) tire; e.g. Michelin makes passenger car tires in the LTX series.

So, it's a good warning: make sure you are not confusing the name of the
tire with it's type. The type will be in letters at the beginning of the
tire designation: P = passenger, LT = light truck, ST = special trailer.
For example, Michelin Pilot LTX P275/65R-18 114H RBL is a passenger car
tire.

--
Eric Greenwell - Washington State, USA
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Hi Gang
There is another important consideration that has not been
thoroughly dealt with in this thread and that is trailer sway with
depends critically on the tires used and their pressures. What is
trailer sway? Well you are tootling down the highway at 50mph and
everything is great and then as you go through 65mph your trailer
begins to swing from side to side much to the consternation of anyone
following you. The only way to reduce this low frequency oscillation
is to slow down fast before the situation can get away from you. So
what are the factors affecting sway? Well the weight of the trailer is
one, the weight of the vehicle hauling, where the trailer wheels are
placed (front, middle or rear) but probably the most critical factor
is the lateral flex of the sidewalls of the tires, wand of course, the
pressure of the tires. When I received my Cobra trailer from Germany
the tire pressures were low about 25psi and what I described above is
a true story. So I pumped the tires up to 40psi and no sway to 70mph
when towing with a heavy vehicle.
In researching trailer sway more fully I found the general consensus
was to use tires with very stiff side walls such as 10 ply non radial
tires (truck tires) and to keep tire pressures up close to the
manufacturers maximum pressures especially if you are going to tow
with a small vehicle. I hope this is of some help.
Dave

On Jan 21, 10:38*am, kd6veb wrote:
Hi Gang
* There is another important consideration that has not been
thoroughly dealt with in this thread and that is trailer sway with
depends critically on the tires used and their pressures. What is
trailer sway? Well you are tootling down the highway at 50mph and
everything is great and then as you go through 65mph your trailer
begins to swing from side to side much to the consternation of anyone
following you. The only way to reduce this low frequency oscillation
is to slow down fast before the situation can get away from you. So
what are the factors affecting sway? Well the weight of the trailer is
one, the weight of the vehicle hauling, where the trailer wheels are
placed (front, middle or rear) but probably the most critical *factor
is the lateral flex of the sidewalls of the tires, wand of course, the
pressure of the tires. When I received my Cobra trailer from Germany
the tire pressures were low about 25psi and what I described above is
a true story. So I pumped the tires up to 40psi and no sway to 70mph
when towing with a heavy vehicle.
* In researching trailer sway more fully I found the general consensus
was to use tires with very stiff side walls such as 10 ply non radial
tires (truck tires) and to keep tire pressures up close to the
manufacturers maximum pressures especially if you are going to tow
with a small vehicle. I hope this is of some help.
Dave

Some people believe that the lateral stiffness of the towing vehicle
rear suspension and tires (tyres) is more important for sway control
than the stiffness in the trailer.

When observing a sway oscillation of a trailer and tow vehicle do you
see translation or rotation at the trailer axle? If both, which is
dominant?

Andy

On Jan 22, 6:52*am, Andy wrote:
On Jan 21, 10:38*am, kd6veb wrote:





Hi Gang
* There is another important consideration that has not been
thoroughly dealt with in this thread and that is trailer sway with
depends critically on the tires used and their pressures. What is
trailer sway? Well you are tootling down the highway at 50mph and
everything is great and then as you go through 65mph your trailer
begins to swing from side to side much to the consternation of anyone
following you. The only way to reduce this low frequency oscillation
is to slow down fast before the situation can get away from you. So
what are the factors affecting sway? Well the weight of the trailer is
one, the weight of the vehicle hauling, where the trailer wheels are
placed (front, middle or rear) but probably the most critical *factor
is the lateral flex of the sidewalls of the tires, wand of course, the
pressure of the tires. When I received my Cobra trailer from Germany
the tire pressures were low about 25psi and what I described above is
a true story. So I pumped the tires up to 40psi and no sway to 70mph
when towing with a heavy vehicle.
* In researching trailer sway more fully I found the general consensus
was to use tires with very stiff side walls such as 10 ply non radial
tires (truck tires) and to keep tire pressures up close to the
manufacturers maximum pressures especially if you are going to tow
with a small vehicle. I hope this is of some help.
Dave

Some people believe that the lateral stiffness of the towing vehicle
rear suspension and tires (tyres) is more important for sway control
than the stiffness in the trailer.

When observing a sway oscillation of a trailer and tow vehicle do you
see translation or rotation at the trailer axle? If both, which is
dominant?

Andy- Hide quoted text -

- Show quoted text -

I'm a big believer in tow vehicle stiffness as THE solution. I've got
a fair amount of experience hauling long (sometimes heavy) trailers.
You can do all you want to the trailer tires, but you'll get the best
effect by stiffening the tow vehicle. Just adding tires with higher
load rating (stiffer sidewalls) yields a huge improvement in sway
control. The downside is harsher ride for passenger cars.