Trailer tires

[flying_monkey]

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,
Ed

[jcarlyle]

Ed,

My research into this question resulted in me concluding that one
should look at the Duro, Maxxis, Denman (in that order) tire brands.
Goodyear Marathons are variable. Carlisle are not recommended (note
that Carlisle also owns Titan). I chose Duros.

Whatever you choose, make SURE that it is an ST tire - this stands for
Special Trailer. And DO NOT run them at low pressure - run them at
whatever the pressure is that is stamped on the sidewall to get
maximum load carrying ability with minimum heat build up.

As for the radial/bias question, radial tires are *not* recommended
when lateral sway is a problem. However, radials do run cooler, and
they provide a softer ride. I chose radials for my Cobra trailer,
since sway has never been an issue, and there is no suspension.

As for longevity, it's recommended that you replace trailer tires
every 5 years. Although they may look "new", the sun and atmosphere
damage the rubber.

Finally, what kind of glider did you buy?

-John

On Jan 20, 10:14 am, flying_monkey > wrote:
> 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,
> Ed

[[email protected]]

Get ready for some great advice on this topic. My pennies worth are to
never run tires below reco. pressure unless you want more traction out
of a mud pit or to lower your vehicle to get it below a bridge. Low
pressure will cause more sidewall flex and lead to an overheat
failure. Get Trailer tires only as they will have an extra sidewall
layer needed for trailer sway that will wear on car tires. I learned
from Charlie Spratt that you want 10% min. of the total tow weight on
the ball to help prevent excessive rear end swaying. Finally, Walmart
sells mounted trailer tires, that's tires and rims together, ready to
go in 13", 14", 15" size that have a C rating. $79, not bad. You can
mount them at the pickpoint and be ready to haul.
Next.....

[KevinFinke]

I'd also check the axle bearings. If they haven't been repacked in the
past couple of years, you'll want to repack them before your trip.

-Kevin

[flying_monkey]

On Jan 20, 10:43*am, " > wrote:
---snip
>Finally, Walmart
> sells mounted trailer tires, that's tires and rims together, ready to
> go in 13", 14", 15" size that have a C rating. $79, not bad. You can
> mount them at the pickpoint and be ready to haul.

Great idea, except that I have no idea what lug spacing is on there,
and there are many possibilities.

[Jim Beckman[_2_]]

At 15:14 20 January 2009, flying_monkey wrote:
>Gang,
>
> It does not appear that the trailer has any suspension,
>so I think I'd run the tires slightly soft, maybe 25-30 psi.

Hard to imagine a trailer without any kind of suspension. Seems to me it
would bounce like crazy over any kind of rough road, not to mention
beating the glider to pieces.

Jim Beckman

[Doug Hoffman]

Jim Beckman wrote:
> At 15:14 20 January 2009, flying_monkey wrote:
>> Gang,
>>
>> It does not appear that the trailer has any suspension,
>> so I think I'd run the tires slightly soft, maybe 25-30 psi.
>
> Hard to imagine a trailer without any kind of suspension. Seems to me it
> would bounce like crazy over any kind of rough road, not to mention
> beating the glider to pieces.

Agreed. An axle using torsion arms for sprung suspension may "look"
like it has no springs, i.e. no leaf springs or coil springs, when in
fact it does.

Regards,

-Doug

[Nigel Pocock]

At 15:27 20 January 2009, jcarlyle wrote:
>Ed,
>
>My research into this question resulted in me concluding that one
>should look at the Duro, Maxxis, Denman (in that order) tire brands.
>Goodyear Marathons are variable. Carlisle are not recommended (note
>that Carlisle also owns Titan). I chose Duros.
>
>Whatever you choose, make SURE that it is an ST tire - this stands for
>Special Trailer. And DO NOT run them at low pressure - run them at
>whatever the pressure is that is stamped on the sidewall to get
>maximum load carrying ability with minimum heat build up.

I would Not do this. The pressure marked on the tyre is the maximum
permitted inflation pressure. This would not allow the tyre to flex and
only the central part of the tyre would be in contact with the road. It
would also bounce all over the place on a rough surface. Inflate to the
reccomended pressure for the trailer. If not available try 35-40psi If the
trailer weighs considerably less than the max tyre load heat build up will
not be a problem.

Nigel

[Dave Doe]

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

[Eric Greenwell]

jcarlyle wrote:

> Whatever you choose, make SURE that it is an ST tire - this stands for
> Special Trailer. And DO NOT run them at low pressure - run them at
> whatever the pressure is that is stamped on the sidewall to get
> maximum load carrying ability with minimum heat build up.

Be aware ST tires have a 60 mph speed rating at the standard pressures.
You can raise the rating to 70 mph if you inflate to required pressure
for this higher speed.

>
> As for the radial/bias question, radial tires are *not* recommended
> when lateral sway is a problem.

Cobra delivers all their trailers with radials. Go to the RV dealers and
look at all travel trailers and 5th wheel trailers, and you will find
out they are all riding on radials. That's because radial tires are far
better tires, even for trailers. The bias ply tire's only advantage is
it's a few dollars cheaper.

If you compare a passenger car radial to a bias ply ST trailer tire, you
might be right.

> However, radials do run cooler, and
> they provide a softer ride.

And they are more road hazard resistant.

>> 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
>> #.

What is in it? It is worth weighing it if you are at all suspicious
about the claimed weight.

Assuming the 950 pounds is right... Unless you are towing this with a
Volkswagen Beetle, it seems unlikely such a light trailer will cause any
problems, regardless of the tires.

>> 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)

The ST inflation chart show a load rating of 850 pounds at 15 psi! This
tire is serious overkill for the weight of your trailer. Even the
smaller ST175/R13 has a 670 pound rating at 15 psi.

If it were my trailer, I'd just put on passenger car tires with a speed
rating about 20 mph higher than I planned to tow, and a 1000 or so pound
load rating, then use the correct pressure for a 600-700 pound load.

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

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

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

[Werner Schmidt]

Hello Doug Hoffman, you wrote at 01.20.2009 23:59

> Jim Beckman wrote:
>> At 15:14 20 January 2009, flying_monkey wrote:
>>> Gang,
>>>
>>> It does not appear that the trailer has any suspension,
>>> so I think I'd run the tires slightly soft, maybe 25-30 psi.
>>
>> Hard to imagine a trailer without any kind of suspension. Seems to me it
>> would bounce like crazy over any kind of rough road, not to mention
>> beating the glider to pieces.
>
> Agreed. An axle using torsion arms for sprung suspension may "look"
> like it has no springs, i.e. no leaf springs or coil springs, when in
> fact it does.

NACK.

Our club owns self-built (in late 60s and early 70s) trailers for our
K-6, K-8, and K-13 without any suspension except the air in the tires.
None of them is bouncing "like crazy over any kind of rough road", and
none of our planes was "beat to pieces" as well.

However, it's strongly recommendend to drive rough roads more slowly
than with a Suspension.

regards
Werner

[Doug Hoffman]

Werner Schmidt wrote:

> NACK.
>
> Our club owns self-built (in late 60s and early 70s) trailers for our
> K-6, K-8, and K-13 without any suspension except the air in the tires.
> None of them is bouncing "like crazy over any kind of rough road", and
> none of our planes was "beat to pieces" as well.

Interesting. But that would be a deal breaker for me when looking to
purchase a used glider.

Regards,

-Doug

[flying_monkey]

Eric,

Thanks for the input. I've seen your helpful and enlightening posts
on many subjects in this forum, so I'm certainly paying attention to
your advice. My comments are inline below.

On Jan 21, 12:34*am, Eric Greenwell > wrote:
> >> 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
> >> #.
>
> What is in it? It is worth weighing it if you are at all suspicious
> about the claimed weight.

What's in it is a Russia AC4C, which weighs 330#. I've seen several
pictures, and am not suspicious of the weight. The owner who I've
talked to on the phone had no doubt of the weight, so I'm assuming he
weighed it at some point.

>
> Assuming the 950 pounds is right... Unless you are towing this with a
> Volkswagen Beetle, it seems unlikely such a light trailer will cause any
> problems, regardless of the tires.
>
> >> *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)
>
> The ST inflation chart show a load rating of 850 pounds at 15 psi! This
> tire is serious overkill for the weight of your trailer. Even the
> smaller ST175/R13 has a 670 pound rating at 15 psi.
>
> If it were my trailer, I'd just put on passenger car tires with a speed
> rating about 20 mph higher than I planned to tow, and a 1000 or so pound
> load rating, then use the correct pressure for a 600-700 pound load.
>

From my experience towing things, some of which is a glider, that's
about where I was thinking of going. I have to buy the tires tonight,
and unless I see some serious refutation of this idea here today,
that's what I'll do. As far as the tire size, I'll probably try to
get around the same rolling radius, as we've already bought a drop
hitch to set the trailer level with the original tires. I'm sure I
can have the dealer look up the recommended inflation pressure for
that load.

I've only seen some pictures of the trailer, and I was inferring that
it had no suspension because there is probably only about 1-2" of
fender clearance, and in the picture, I can't see that the fenders are
free to move with the tires.

Ed

[Andy[_1_]]

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

[Jim Beckman[_2_]]

At 12:26 21 January 2009, flying_monkey wrote:
>
>I've only seen some pictures of the trailer, and I was inferring that
>it had no suspension because there is probably only about 1-2" of
>fender clearance, and in the picture, I can't see that the fenders are
>free to move with the tires.

It seems unlikely, but still possible, that the trailer suspension
has collapsed. More likely with one of those internal torsion
setups - guys at the field have had trouble with fixing those.
You might want to make sure what the situation is, because
the fix could be expensive.

Jim Beckman

[jcarlyle]

Eric has a point - this is an unusually low weight glider/trailer
combination, and thus warrants a different approach.

For the more typical glider trailer with 15m glider, though, I stick
by my suggestion to use ST radials, as they have sidewalls
specifically designed with trailers in mind. Their sidewalls are
stiffer than a passenger (P) or light truck (LT) tire, are more
flexible when cornering and backing, and are designed for extended,
non-stop towing. Note that LT tires are also designed to carry higher
loads than ST tires, so they're going in the wrong direction for a
glider trailer.

-John

On Jan 21, 12:34 am, Eric Greenwell > wrote:
>
> Assuming the 950 pounds is right... Unless you are towing this with a
> Volkswagen Beetle, it seems unlikely such a light trailer will cause any
> problems, regardless of the tires.
>
> The ST inflation chart show a load rating of 850 pounds at 15 psi! This
> tire is serious overkill for the weight of your trailer. Even the
> smaller ST175/R13 has a 670 pound rating at 15 psi.
>
> If it were my trailer, I'd just put on passenger car tires with a speed
> rating about 20 mph higher than I planned to tow, and a 1000 or so pound
> load rating, then use the correct pressure for a 600-700 pound load.

[Eric Greenwell]

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
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

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

[kd6veb]

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

[Eric Greenwell]

Eric Greenwell wrote:
> jcarlyle wrote:
>
>> Whatever you choose, make SURE that it is an ST tire - this stands
>> for Special Trailer. And DO NOT run them at low pressure - run them
>> at whatever the pressure is that is stamped on the sidewall to get
>> maximum load carrying ability with minimum heat build up.
>
> Be aware ST tires have a 60 mph speed rating at the standard
> pressures. You can raise the rating to 70 mph if you inflate to
> required pressure for this higher speed.

I didn't remember this correctly: According to a Goodyear general
information sheet:

> Based on industry standards, if tires with the ST designation are
> used at speeds between 66 and 75 mph, it is necessary to increase the
> cold inflation pressures by 10 psi above the recommended pressure for
> the load.
> o Do not exceed the maximum pressure for the wheel.
> o If the maximum pressure for the wheel prohibits the increase of air
> pressure, then the maximum speed must be restricted to 65 mph.
> o The cold inflation pressure must not exceed 10 psi beyond the inflation
> specified for the maximum load of the tire.
>
--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

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

[Eric Greenwell]

jcarlyle wrote:
> Eric has a point - this is an unusually low weight glider/trailer
> combination, and thus warrants a different approach.
>
> For the more typical glider trailer with 15m glider, though, I stick
> by my suggestion to use ST radials, as they have sidewalls
> specifically designed with trailers in mind. Their sidewalls are
> stiffer than a passenger (P) or light truck (LT) tire,

According to this page on the Subaru.com website about trailer tires,
the ST is in between the passenger (P) or light truck (LT) tire in
sidewall stiffness.

http://tinyurl.com/9jesg

They also mention ST tires better withstand storage and deterioration
from the elements,including sunlight and ozone, due to the rubber
formulations.

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

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

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

[flying_monkey]

Well, folks, the die is cast. Last night I bought 2 Carlisle ST
205R75 tires. I'll let you know what happens.

Ed

[Andy[_1_]]

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

[flying_monkey]

On Jan 22, 7:24*am, flying_monkey > wrote:
> Well, folks, the die is cast. *Last night I bought 2 Carlisle ST
> 205R75 tires. *I'll let you know what happens.
>
> Ed

Well, the trip's complete, no problems. We stopped at a WalMart about
5 miles from the glider pickup location, and had the tires changed,
setting the pressure at 40psi. Their max pressure was 50, but we
thought that with the load as low as it was, somewhat lower would be
better. With the above described tires, the trailer towed flawlessly
at speeds of 70-75 mph for miles at a time, and probably intermittent
80 mph stretches. The tires and bearings stayed completely cool.

Regarding the suspension, it turns out that there is torsion bar
suspension, which hooks some way into the arm which supports the hub.
This arm a casting about 9 inches long welded onto the end of the
torsion rod. The suspension is totally sacked out, so is just a solid
ride. Even with both wheels off the ground, the suspension just sits
in the maximally compressed position. The tire man said that usually
there is an adjustment bolt somewhere on the axle near the center
which adjusts the ride height, but nothing like that was seen here.
I'm almost thinking that we'll have to grind off the axle and weld on
a new one to solve this problem. Anybody seen this before, or have
any ideas?

I see that NorthernTool has some axles similar to this, but the lowest
capacity is 2000#. If something similar to this was on our trailer,
it might seem as if it was locked up but be just sitting at the
beginning of its travel and there's not enough weight to make it
move. I doubt that, though, because the trailer tire sits within 1/2
inch of contacting the fixed fender, and in the whole trip, there's no
evidence that it ever touched the fender.

TIA,
Ed

[[email protected]]

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.

[Dave Doe]

In article <1af7d33b-3bbe-42a6-bb11-1b8c67ba13e9
@r28g2000vbp.googlegroups.com>, says...
> On Jan 22, 7:24*am, flying_monkey > wrote:
> > Well, folks, the die is cast. *Last night I bought 2 Carlisle ST
> > 205R75 tires. *I'll let you know what happens.
> >
> > Ed
>
> Well, the trip's complete, no problems. We stopped at a WalMart about
> 5 miles from the glider pickup location, and had the tires changed,
> setting the pressure at 40psi. Their max pressure was 50, but we
> thought that with the load as low as it was, somewhat lower would be
> better. With the above described tires, the trailer towed flawlessly
> at speeds of 70-75 mph for miles at a time, and probably intermittent
> 80 mph stretches. The tires and bearings stayed completely cool.
>
> Regarding the suspension, it turns out that there is torsion bar
> suspension, which hooks some way into the arm which supports the hub.
> This arm a casting about 9 inches long welded onto the end of the
> torsion rod. The suspension is totally sacked out, so is just a solid
> ride. Even with both wheels off the ground, the suspension just sits
> in the maximally compressed position. The tire man said that usually
> there is an adjustment bolt somewhere on the axle near the center
> which adjusts the ride height, but nothing like that was seen here.
> I'm almost thinking that we'll have to grind off the axle and weld on
> a new one to solve this problem. Anybody seen this before, or have
> any ideas?

Torson bar suspension is typically adjusted quite easily. The end of the
torsion bar should be splined. You should be able to take out the bar
with the trailer "de-loaded" (jack the weight off it), and reset it in -
turned around some - and let the weight back on. Hopefully, you now
have suspension again.

--
Duncan

[flying_monkey]

I never thought of that. Thanks. But what holds the removable part
into the axle? I can't see anything. I don't see any kind of
setscrew anywhere. The outside end is just the end of a square tube,
and the part attached to the wheel is welded to the torsion element.

Ed

> Torson bar suspension is typically adjusted quite easily. The end of the
> torsion bar should be splined. *You should be able to take out the bar
> with the trailer "de-loaded" (jack the weight off it), and reset it in -
> turned around some - and let the weight back on. *Hopefully, you now
> have suspension again.
>
> --
> Duncan

[sisu1a]

> Regarding the suspension, it turns out that there is torsion bar
> suspension, which hooks some way into the arm which supports the hub.
> This arm a casting about 9 inches long welded onto the end of the
> torsion rod. *The suspension is totally sacked out, so is just a solid
> ride. *Even with both wheels off the ground, the suspension just sits
> in the maximally compressed position. *The tire man said that usually
> there is an adjustment bolt somewhere on the axle near the center
> which adjusts the ride *height, but nothing like that was seen here.
> I'm almost thinking that we'll have to grind off the axle and weld on
> a new one to solve this problem. *Anybody seen this before, or have
> any ideas?
> TIA,
> Ed

Ed, buy yourself a new Torflex axle of the correct size/rating (get
one with the electric brake flange on it so you can upgrade
someday...). It's an incredibly easy install, and your trailer will
ride like a dream with it's freshly recharged independent rubber-band
suspension and your ship will thank you for it. The elastomer bands in
these wear out over time (not as bad with newer techniques/
formulas...) and go flat as yours have. If you have elastomer
suspension (as it sounds like you have...) , there's no 'fix', there's
'replace'. The axle is only a couple hundred bucks though, and the
Dexter peeps are mighty helpful in the selection process should you
need to call them.
http://www.dexteraxle.com/torflex_axles I will not admit on this
forum how fast my trailer has been 'stability tested' up to with one
of these axles, so lets just say waaay too fast ;-)

-Paul

[Dave Doe]

OK, mayby I got yer wrong - maybe it's a different "torsion bar" setup,
quite common on trailers in New Zealand - they're called Duro-Torque
(made by Trojan I think) - and work like this...

Two square hollow bars (square tubes), one is smaller and inserted into
the other at a 45 degree offset. And set into the "gaps" - are big
rubber bits.

These are fixed, by way of the way they're contructed. Their downfall
is, that when the turn round to a point, they basically roll round and
fail . The only fix is usually to replace the rubber (and they're damn
hard to seperate the two box pieces, given the rubber jammed in there.

I'd find out who makes them, or who can service them, and see if you can
get 'em reconditioned, or replaced - typically not very expensive.

--
Duncan

In article <3d6a5cbb-6d19-4636-90bf-e56fb1f8a036
@o36g2000yqh.googlegroups.com>, says...
> I never thought of that. Thanks. But what holds the removable part
> into the axle? I can't see anything. I don't see any kind of
> setscrew anywhere. The outside end is just the end of a square tube,
> and the part attached to the wheel is welded to the torsion element.
>
> Ed
>
> > Torson bar suspension is typically adjusted quite easily. The end of the
> > torsion bar should be splined. *You should be able to take out the bar
> > with the trailer "de-loaded" (jack the weight off it), and reset it in -
> > turned around some - and let the weight back on. *Hopefully, you now
> > have suspension again.
> >
> > --
> > Duncan
>
>

[Dave Doe]

PS: the link that sisu1a posted...

http://www.dexteraxle.com/torflex_axles

Is exactly what I meant, re Duro-Torque suspension.

And my advice still stands, get 'em serviced (normally replaced as
that's typically the only option) by the maker or agent that can do it.

--
Duncan

In article <3d6a5cbb-6d19-4636-90bf-e56fb1f8a036
@o36g2000yqh.googlegroups.com>, says...
> I never thought of that. Thanks. But what holds the removable part
> into the axle? I can't see anything. I don't see any kind of
> setscrew anywhere. The outside end is just the end of a square tube,
> and the part attached to the wheel is welded to the torsion element.
>
> Ed
>
> > Torson bar suspension is typically adjusted quite easily. The end of the
> > torsion bar should be splined. *You should be able to take out the bar
> > with the trailer "de-loaded" (jack the weight off it), and reset it in -
> > turned around some - and let the weight back on. *Hopefully, you now
> > have suspension again.
> >
> > --
> > Duncan
>
>