glider trailer tires

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

thanks,
Ken

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

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

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

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

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

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

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

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

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