Tire Stiffness & trailer swaying

[chris]

Several people have had good luck towing a glider with a Subaru
Forester.
I do not know why mine is different.
I just bought a 2004 Forester tried to tow with it. Mine is a
nightmare. It is unstable above 50mph. It has a lot of side to side
sway above 50mph if there is any steering input. It is almost
harmonic in nature – it does not dampen out quickly. If feels like
you are driving on Jello. It feels like the problem is much more the
tires than the suspension. Though that is hard to prove.

Even when parked if you push on the hitch with your foot the Forester
will sway side to side [right and left] a lot. You can watch the rim
move right and left in and out of the tire. I think the sidewalls are
just really weak. The tread is probably relatively soft also.

The Forester's tires are Yokohama Geolander G900 P215/60 R16 94H.
Even in normal driving the steering response and cornering are poor.
[Other Foresters may be equipped with 15" tires, and other models of
Geolander tires – rather than the G900].

My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H – it
is stable, and if you push sideways it does not sway side to side
anywhere near the degree that the Forester does. Steering response
and cornering are good.

The Geolander G900 has a tall soft sidewall, it is 4.500" above the
rim rather than 3.625" for the P4000 [24%higher].

My best idea right now is to change to a shorter and stiffer sidewall
tire.
I am considering changing from P215/60 R16 94H
- an "H" rate tire with 60% width/height ratio, to
Bridgestone Turanza LS-V 225/50R16 92V - this is a V rate tire so the
sidewall is stiffer and at a 50 or 55 ratio it is shorter.
This is the V rated version of the tire that some other Forester
owners have [LS-H]. The tread should also be a harder sports car like
compound.



Some of these tires are rated and discussed on www.tirerack.com. It
seems that Steering response and cornering stability are good
expressions of my issue.
On tirerack there are a mass of good comments on the Turanza tire –
though I doubt anyone is towing. As far as I can tell everyone on
"tirerack" hates the geolander 900 like on mine.


Does anyone else have any Experience changing to a shorter V rated
tire for better stability?


My trailer does great and stable to 85+mph behind my Mazda MX-6, so I
do not think it is the trailer. The trailer is a 1979 Komet with a
Mosquito. It weighs ~1800lbs [816kg]. The tongue weight is 153lbs
[69kg]. The Forester's manual says to keep the tongue weight between
8-11% of the trailer. 8%=144lbs [65kg] 11%=198lbs [90kg].
[the max allowed is 200lbs on the tongue] The manual transmission
version of the Forester is rated for 2400lbs [1088kg] towing capacity.


I have already tried raising the tire pressure on the rear tires to
41psi [2.8bar] as recommended by the manual. The trailer tires are
about 40psi.


Chris Ruf

[Bill Daniels]

"chris" > wrote in message
om...
> Several people have had good luck towing a glider with a Subaru
> Forester.
> I do not know why mine is different.
> I just bought a 2004 Forester tried to tow with it. Mine is a
> nightmare. It is unstable above 50mph. It has a lot of side to side
> sway above 50mph if there is any steering input. It is almost
> harmonic in nature - it does not dampen out quickly. If feels like
> you are driving on Jello. It feels like the problem is much more the
> tires than the suspension. Though that is hard to prove.
>
> Even when parked if you push on the hitch with your foot the Forester
> will sway side to side [right and left] a lot. You can watch the rim
> move right and left in and out of the tire. I think the sidewalls are
> just really weak. The tread is probably relatively soft also.
>
> The Forester's tires are Yokohama Geolander G900 P215/60 R16 94H.
> Even in normal driving the steering response and cornering are poor.
> [Other Foresters may be equipped with 15" tires, and other models of
> Geolander tires - rather than the G900].
>
> My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> is stable, and if you push sideways it does not sway side to side
> anywhere near the degree that the Forester does. Steering response
> and cornering are good.
>
> The Geolander G900 has a tall soft sidewall, it is 4.500" above the
> rim rather than 3.625" for the P4000 [24%higher].
>
> My best idea right now is to change to a shorter and stiffer sidewall
> tire.
> I am considering changing from P215/60 R16 94H
> - an "H" rate tire with 60% width/height ratio, to
> Bridgestone Turanza LS-V 225/50R16 92V - this is a V rate tire so the
> sidewall is stiffer and at a 50 or 55 ratio it is shorter.
> This is the V rated version of the tire that some other Forester
> owners have [LS-H]. The tread should also be a harder sports car like
> compound.
>
>
>
> Some of these tires are rated and discussed on www.tirerack.com. It
> seems that Steering response and cornering stability are good
> expressions of my issue.
> On tirerack there are a mass of good comments on the Turanza tire -
> though I doubt anyone is towing. As far as I can tell everyone on
> "tirerack" hates the geolander 900 like on mine.
>
>
> Does anyone else have any Experience changing to a shorter V rated
> tire for better stability?
>
>
> My trailer does great and stable to 85+mph behind my Mazda MX-6, so I
> do not think it is the trailer. The trailer is a 1979 Komet with a
> Mosquito. It weighs ~1800lbs [816kg]. The tongue weight is 153lbs
> [69kg]. The Forester's manual says to keep the tongue weight between
> 8-11% of the trailer. 8%=144lbs [65kg] 11%=198lbs [90kg].
> [the max allowed is 200lbs on the tongue] The manual transmission
> version of the Forester is rated for 2400lbs [1088kg] towing capacity.
>
>
> I have already tried raising the tire pressure on the rear tires to
> 41psi [2.8bar] as recommended by the manual. The trailer tires are
> about 40psi.
>
>
> Chris Ruf
>

You're right that tow vehicles often get overlooked when trailer sway is an
issue.

You can increase the stiffness of a tire a lot by just increasing the air
pressure. Try adding another 10PSI to the normal inflation pressure and see
what happens. If that helps, sidewall stiffness is likely to be the
problem - if not, the problem may be elsewhere.

There is another issue with SUV's suspensions that are intended for real
offroad operation. Often roll stiffness is greatly reduced compared to
normal passenger vehicles to minimize the neck-snapping side-to-side motion
on rough trails. This softer roll compliance combined with a higher CG also
means that trailer sway will induce a side-to-side rolling motion in the SUV
that, in turn, augments the trailer sway in a nasty feedback loop.

The fix is to replace the wimpy rear sway bar with a stiffer aftermarket one
from a company like Addco. Depending on the vehicle, you may also want to
replace the soft rubber sway bar bushings with a harder material like
urethane. The penalty for this modification is that the ride will be less
comfortable on rough surfaces.

Bill Daniels

[Scott Correa]

"chris" > wrote in message
om...
> The Forester's tires are Yokohama Geolander G900 P215/60 R16 94H.
> Even in normal driving the steering response and cornering are poor.
> [Other Foresters may be equipped with 15" tires, and other models of
> Geolander tires - rather than the G900].
>

Chris.
My Tahoe on Geolanders (nice tire) handles very poorly at less than
44 psi all 4 corners. This is a truck rated tire and very succeptable to
underfilled type of problems. The symptoms sound like low tire pressure.
First, have a tire shop check the pressures. THEN use your gauge to make
sure
it is in the ballpark. I've seen cheapo gauges read way off after being
dropped,
not to mention not being very close to begin with.

Does your hitch have sufficient drop. If you are using the same
reciever/ball
you probably need to change top a lower dropped unit. If the ball is too
high
and the trailer is appreciably "nose up" they seem to want to oscillate
back and forth
without much provocation.

Just thiinking out loud................

Scott Correa

[Chris Ruf]

Since my original write up I have learned the following:
The dealer told me that the 2004 model is the first to be equipped with the
Geolander G900 tires, previous years had a different model tire. This is
the only change to the suspension that he is aware of between the 2003 and
2004 model.

The Maximum tire pressure on the tires is 44psi, so I upped the rear
pressure to 44psi and the fronts to 41. [for towing the manual says 29psi
front, 41psi rear]. I also changed the hitch from a straight one to a "drop
hitch" it is now 1.5" lower than the straight one. The drop hitch is about
4.0" shorter than the "lift hitch" [bent receiver hitch] that I originally
tried. The hitch ball is on a short receiver.
A test drive showed that the lower hitch/ball placement and the higher tire
pressures are an improvement. However still not acceptable. I think the
higher pressure stiffened the tires but not enough and the tread is still
too soft.

I have heard another Forester owner has had good luck with 75-100lbs of
tongue weight. An additional test drive was done after I moved several items
out of the front of the trailer to the back of the Forester. This reduced
the tongue weight to 118lbs [down 35lbs from 153]. The swaying seemed worse
with the lower tongue weight. [This follows the logic I have heard many
times].

Chris Ruf

[CH]

I don't know how long it does take for certain people
to recognise, that SUV's and 4-wheel drive cars

- are built for use in the outback and not for driving in towns
- have a high CG and are handling worse on windy roads than
any normal cars with good suspension (European/Japan cars)
- have big tires to suit off road driving, which are worse on
normal roads, worse than normal or low profile tires.
- often do not have independent side stable suspension on the
back which give them bad side stability (push the car sideways
on the rear bumper and let it go - if the hole car swings around
the vertical yaw axis then it does not suit towing)
- have bad aerodynamics and produce more turbulence behind,
which has again bad influence on the trailers stability.

Conclusions:
Quite any car is better for towing, in handling and safety than
a SUV.

I prefer to rent a 4-wheel drive for holiday in the outback,
own a small car with common rail turbo diesel engine
(2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
per 100km consumption).
Like that I can pay many tows with the saved money I do not
spend on petrol.
I can tow any trailer with brakes up to 1500kg stable with
100km/.
And on a windy road the SUV just disappear in the rear mirror.
But I cannot compete offroad with these monsters. I don't mind
because I only need offroad function perhaps 7 days a year.
How often do you need offroad capability?
Think of it when you buy the next car.
Chris


"chris" > wrote in message
om...
> Several people have had good luck towing a glider with a Subaru
> Forester.

> My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> is stable, and if you push sideways it does not sway side to side
> anywhere near the degree that the Forester does. Steering response
> and cornering are good.

> Chris Ruf
>

[tango4]

Heresy! Devil out, be gone.

You are preaching to the 'hit it with a bigger sledgehammer' mob here lad.
If it aint got 5 litres of V8 petrol engine and 200kgs of tongue weight it
aint right!

:-)

Ian - 2300cc ( petrol I will admit ) Ford MPV and about 53 kgs tongue weight
a proven 100mph combination!


"CH" > wrote in message
...
> I don't know how long it does take for certain people
> to recognise, that SUV's and 4-wheel drive cars
>
> - are built for use in the outback and not for driving in towns
> - have a high CG and are handling worse on windy roads than
> any normal cars with good suspension (European/Japan cars)
> - have big tires to suit off road driving, which are worse on
> normal roads, worse than normal or low profile tires.
> - often do not have independent side stable suspension on the
> back which give them bad side stability (push the car sideways
> on the rear bumper and let it go - if the hole car swings around
> the vertical yaw axis then it does not suit towing)
> - have bad aerodynamics and produce more turbulence behind,
> which has again bad influence on the trailers stability.
>
> Conclusions:
> Quite any car is better for towing, in handling and safety than
> a SUV.
>
> I prefer to rent a 4-wheel drive for holiday in the outback,
> own a small car with common rail turbo diesel engine
> (2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
> per 100km consumption).
> Like that I can pay many tows with the saved money I do not
> spend on petrol.
> I can tow any trailer with brakes up to 1500kg stable with
> 100km/.
> And on a windy road the SUV just disappear in the rear mirror.
> But I cannot compete offroad with these monsters. I don't mind
> because I only need offroad function perhaps 7 days a year.
> How often do you need offroad capability?
> Think of it when you buy the next car.
> Chris
>
>
> "chris" > wrote in message
> om...
> > Several people have had good luck towing a glider with a Subaru
> > Forester.
>
> > My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> > is stable, and if you push sideways it does not sway side to side
> > anywhere near the degree that the Forester does. Steering response
> > and cornering are good.
>
> > Chris Ruf
> >
>
>

[Doug Hoffman]

Not all SUVs are created equal (I won't get into all-wheel-drive cars,
many of which are *not* designed for offroad use). My Jeep Liberty is
nicely sized for my purposes. I had a landout last year in a freshly
plowed field. Nothing but a very off-road-capable 4WD vehicle could
have performed the retrieve. I was sure glad I had the Jeep! Then
there are the cars I've pulled out of ditches with it during the
winter.

But you are right about the issues with high CG, off-road tires, etc.
Anyone who drives such an SUV like a sports car is a fool.

-Doug


"CH" > wrote in message >...
> I don't know how long it does take for certain people
> to recognise, that SUV's and 4-wheel drive cars
>
> - are built for use in the outback and not for driving in towns
> - have a high CG and are handling worse on windy roads than
> any normal cars with good suspension (European/Japan cars)
> - have big tires to suit off road driving, which are worse on
> normal roads, worse than normal or low profile tires.
> - often do not have independent side stable suspension on the
> back which give them bad side stability (push the car sideways
> on the rear bumper and let it go - if the hole car swings around
> the vertical yaw axis then it does not suit towing)
> - have bad aerodynamics and produce more turbulence behind,
> which has again bad influence on the trailers stability.
>
> Conclusions:
> Quite any car is better for towing, in handling and safety than
> a SUV.
>
> I prefer to rent a 4-wheel drive for holiday in the outback,
> own a small car with common rail turbo diesel engine
> (2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
> per 100km consumption).
> Like that I can pay many tows with the saved money I do not
> spend on petrol.
> I can tow any trailer with brakes up to 1500kg stable with
> 100km/.
> And on a windy road the SUV just disappear in the rear mirror.
> But I cannot compete offroad with these monsters. I don't mind
> because I only need offroad function perhaps 7 days a year.
> How often do you need offroad capability?
> Think of it when you buy the next car.
> Chris

[Bill Daniels]

"GeorgeB" > wrote in message
...
> On Fri, 26 Sep 2003 03:04:36 GMT, "Chris Ruf"
> > wrote:
>
> >The Maximum tire pressure on the tires is 44psi, so I upped the rear
> >pressure to 44psi and the fronts to 41. [for towing the manual says
29psi
> >front, 41psi rear].
>
> Generally, you don't want to harden up the fronts ... the sideways
> force from the hitch doesn't generate much torque to bother them.
> Hard fronts, even not pulling a trailer, often cause high steering
> sensitivity. Tongue weight lightens the load on them. That is one of
> the reasons for a weight-distributing hitch.
>

Be careful here to understand the four wheel drive system in your vehicle.
(I think the Subaru uses a central differential and not a viscous coupling
for its full-time 4WD.) However, any full-time 4WD vehicle will suffer very
expensive damage to the transfer case if the front and rear axles turn at
different speeds for an extended time as they would with different tire
pressures.

My Jeep uses and central viscous coupling instead of a center differential
so all four tires must always be the same diameter else very expensive
repairs are in the offing.

Bill Daniels

[Tim]

"tango4" >s comments read:
>
>Ian - 2300cc ( petrol I will admit ) Ford MPV and about 53 kgs tongue weight
>a proven 100mph combination!

Ian a proven TINSFOS man

Tim - Peugeot 106 1100cc
A legal 60mph combination ;)

--
Tim - ASW20CL "20"

[ADP]

I guess the "Ariana Wussies" have hit this forum - even if they aren't from
the US
Give me a break, there are so-called SUVs that can blow the doors off of
anything less than a
new Ferrari and out corner anything built in Japan.
In fact, I'll take my two wheel drive pickup truck and challenge you in
whatever 1000 cc turkey you drive
and race you an any road, any track, anywhere and drub you soundly - and
I'll drub you in a straightaway towing a 2000# load.
And, yes folks, I really can do it!

If you want to push this BS, go to Green Peace. Drive what you want where
and when you want.

The other responses to this thread were on point, what will make his vehicle
handle better while towing.
Please get with it.

Let the games begin!

ADP


"CH" > wrote in message
...
> I don't know how long it does take for certain people
> to recognise, that SUV's and 4-wheel drive cars
>
> - are built for use in the outback and not for driving in towns
> - have a high CG and are handling worse on windy roads than
> any normal cars with good suspension (European/Japan cars)
> - have big tires to suit off road driving, which are worse on
> normal roads, worse than normal or low profile tires.
> - often do not have independent side stable suspension on the
> back which give them bad side stability (push the car sideways
> on the rear bumper and let it go - if the hole car swings around
> the vertical yaw axis then it does not suit towing)
> - have bad aerodynamics and produce more turbulence behind,
> which has again bad influence on the trailers stability.
>
> Conclusions:
> Quite any car is better for towing, in handling and safety than
> a SUV.
>
>

[GeorgeB]

On Fri, 26 Sep 2003 12:57:44 GMT, "Bill Daniels"
> wrote:

>However, any full-time 4WD vehicle will suffer very
>expensive damage to the transfer case if the front and rear axles turn at
>different speeds for an extended time as they would with different tire
>pressures.

That is what I thought for a long time, and it may be true, but 2
friends of mine who are tire engineers at Michelin tell me that
inflation pressure has almost no effect on revolutions per mile ...
the belt lenght doesn't change and thus the pressure affects flexing,
sidewall height, but not effective circumference.

That said, the revolution per mile numbers on manufacturers' websites
always give a pressure ...

I don't know.

[BPattonsoa]

>I guess the "Ariana Wussies" have hit this forum - even if they aren't from
>the US
>Give me a break, there are so-called SUVs that can blow the doors off of
>anything less than a
>new Ferrari and out corner anything built in Japan.
>In fact, I'll take my two wheel drive pickup truck and challenge you in
>whatever 1000 cc turkey you drive
>and race you an any road, any track, anywhere and drub you soundly - and
>I'll drub you in a straightaway towing a 2000# load.
>And, yes folks, I really can do it!
>

Now here is a man who loves 1 mile start circles and 6 inch finishes. Man
after my own heart.
(Please include me in you will)

Bruce Patton

[Larry Goddard]

Chris,

Another often overlooked issue is the length of the hitch (i.e., the
distance it protrudes from the back of the car). Shortening the hitch
even a couple of inches can drastically improve the handling. Think about
it... if you could mount the hitch ball on top center of the rear axle,
then any sort of steering induced oscillations would be non-existent.
Obviously that cannot be done with a standard vehicle. But at times you
can find a hitch that will fit into the receiver that can be cut down
shorter. I did that on one of my hitches and it made a world of
difference.

Larry Goddard
"01" USA

PS> You might even be able to mount the hitch assembly further forward.

chris wrote:

> Several people have had good luck towing a glider with a Subaru
> Forester.
> I do not know why mine is different.
> I just bought a 2004 Forester tried to tow with it. Mine is a
> nightmare. It is unstable above 50mph. It has a lot of side to side
> sway above 50mph if there is any steering input. It is almost
> harmonic in nature – it does not dampen out quickly. If feels like
> you are driving on Jello. It feels like the problem is much more the
> tires than the suspension. Though that is hard to prove.
>
> Even when parked if you push on the hitch with your foot the Forester
> will sway side to side [right and left] a lot. You can watch the rim
> move right and left in and out of the tire. I think the sidewalls are
> just really weak. The tread is probably relatively soft also.
>
> The Forester's tires are Yokohama Geolander G900 P215/60 R16 94H.
> Even in normal driving the steering response and cornering are poor.
> [Other Foresters may be equipped with 15" tires, and other models of
> Geolander tires – rather than the G900].
>
> My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H – it
> is stable, and if you push sideways it does not sway side to side
> anywhere near the degree that the Forester does. Steering response
> and cornering are good.
>
> The Geolander G900 has a tall soft sidewall, it is 4.500" above the
> rim rather than 3.625" for the P4000 [24%higher].
>
> My best idea right now is to change to a shorter and stiffer sidewall
> tire.
> I am considering changing from P215/60 R16 94H
> - an "H" rate tire with 60% width/height ratio, to
> Bridgestone Turanza LS-V 225/50R16 92V - this is a V rate tire so the
> sidewall is stiffer and at a 50 or 55 ratio it is shorter.
> This is the V rated version of the tire that some other Forester
> owners have [LS-H]. The tread should also be a harder sports car like
> compound.
>
> Some of these tires are rated and discussed on www.tirerack.com. It
> seems that Steering response and cornering stability are good
> expressions of my issue.
> On tirerack there are a mass of good comments on the Turanza tire –
> though I doubt anyone is towing. As far as I can tell everyone on
> "tirerack" hates the geolander 900 like on mine.
>
> Does anyone else have any Experience changing to a shorter V rated
> tire for better stability?
>
> My trailer does great and stable to 85+mph behind my Mazda MX-6, so I
> do not think it is the trailer. The trailer is a 1979 Komet with a
> Mosquito. It weighs ~1800lbs [816kg]. The tongue weight is 153lbs
> [69kg]. The Forester's manual says to keep the tongue weight between
> 8-11% of the trailer. 8%=144lbs [65kg] 11%=198lbs [90kg].
> [the max allowed is 200lbs on the tongue] The manual transmission
> version of the Forester is rated for 2400lbs [1088kg] towing capacity.
>
> I have already tried raising the tire pressure on the rear tires to
> 41psi [2.8bar] as recommended by the manual. The trailer tires are
> about 40psi.
>
> Chris Ruf
>

[Chris OCallaghan]

100kph? Do you drive backwards on retrieves for sport? Or perhaps you
always land close enough to the airport that there's no hurry...

Sing what praises you may, they echo hollow among the leather clad
comforts of my 7000 lbs of 4x4 SUV... the best you can achieve with
your little brand-name putt-putt is "adequacy." If you want to excel,
be the envy of every man and the desire of every woman, there's no
substitute for SIZE, POWER, and TRACTION.

But fear not, I'm sure you'll find friends for whom "adeqaute" is
enough.

[tango4]

Tim

You are truly a SIFOW proponent. An 1100cc 106 and an ASW20 is an impressive
combination! I salute you sir!

Ian


"Tim" > wrote in message
...
> "tango4" >s comments read:
> >
> >Ian - 2300cc ( petrol I will admit ) Ford MPV and about 53 kgs tongue
weight
> >a proven 100mph combination!
>
> Ian a proven TINSFOS man
>
> Tim - Peugeot 106 1100cc
> A legal 60mph combination ;)
>
> --
> Tim - ASW20CL "20"

[Shaber CJ]

>Then
>there are the cars I've pulled out of ditches with it during the
>winter.

I just returned from visiting Idaho, where I grew up. I was feeling home sick
until I read your comment above. I just remembered why I like San Diego so
much.

[szd41a]

Bingo!!!
I never had a better ride puliing my glider-trailer than with My Honda Civic
(90 H.P). Drove it all the way from Montreal to the ridge in Pensylvania, up
the steep mountain roads of Lake Placid, or Sugarbush, many outlandings and
800 km drives to the repair shop. Very steady drive at 110 km/h. I had this
car for eleven years, and I miss my Civic sinceI bought a new car with more
horse power, and a higher c.g. !!!! I guess you want the shortest distance
between rear axle and hitch point (obviously) and the lowest c.g (automobile
engeneering is regeressing) and also all what is mentioned below. It amazes
me mucho to see all theese people driving SUV thinking they are safer!!!
BQ
"CH" > a écrit dans le message de
...
> I don't know how long it does take for certain people
> to recognise, that SUV's and 4-wheel drive cars
>
> - are built for use in the outback and not for driving in towns
> - have a high CG and are handling worse on windy roads than
> any normal cars with good suspension (European/Japan cars)
> - have big tires to suit off road driving, which are worse on
> normal roads, worse than normal or low profile tires.
> - often do not have independent side stable suspension on the
> back which give them bad side stability (push the car sideways
> on the rear bumper and let it go - if the hole car swings around
> the vertical yaw axis then it does not suit towing)
> - have bad aerodynamics and produce more turbulence behind,
> which has again bad influence on the trailers stability.
>
> Conclusions:
> Quite any car is better for towing, in handling and safety than
> a SUV.
>
> I prefer to rent a 4-wheel drive for holiday in the outback,
> own a small car with common rail turbo diesel engine
> (2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
> per 100km consumption).
> Like that I can pay many tows with the saved money I do not
> spend on petrol.
> I can tow any trailer with brakes up to 1500kg stable with
> 100km/.
> And on a windy road the SUV just disappear in the rear mirror.
> But I cannot compete offroad with these monsters. I don't mind
> because I only need offroad function perhaps 7 days a year.
> How often do you need offroad capability?
> Think of it when you buy the next car.
> Chris
>
>
> "chris" > wrote in message
> om...
> > Several people have had good luck towing a glider with a Subaru
> > Forester.
>
> > My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> > is stable, and if you push sideways it does not sway side to side
> > anywhere near the degree that the Forester does. Steering response
> > and cornering are good.
>
> > Chris Ruf
> >
>
>

[Larry Johnson]

"szd41a" > wrote in message >...
> Bingo!!!
> I never had a better ride puliing my glider-trailer than with My Honda Civic
> (90 H.P). Drove it all the way from Montreal to the ridge in Pensylvania, up
> the steep mountain roads of Lake Placid, or Sugarbush, many outlandings and
> 800 km drives to the repair shop. Very steady drive at 110 km/h. I had this
> car for eleven years, and I miss my Civic sinceI bought a new car with more
> horse power, and a higher c.g. !!!! I guess you want the shortest distance
> between rear axle and hitch point (obviously) and the lowest c.g (automobile
> engeneering is regeressing) and also all what is mentioned below. It amazes
> me mucho to see all theese people driving SUV thinking they are safer!!!
> BQ
> "CH" > a écrit dans le message de
> ...
> > I don't know how long it does take for certain people
> > to recognise, that SUV's and 4-wheel drive cars
> >
> > - are built for use in the outback and not for driving in towns
> > - have a high CG and are handling worse on windy roads than
> > any normal cars with good suspension (European/Japan cars)
> > - have big tires to suit off road driving, which are worse on
> > normal roads, worse than normal or low profile tires.
> > - often do not have independent side stable suspension on the
> > back which give them bad side stability (push the car sideways
> > on the rear bumper and let it go - if the hole car swings around
> > the vertical yaw axis then it does not suit towing)
> > - have bad aerodynamics and produce more turbulence behind,
> > which has again bad influence on the trailers stability.
> >
> > Conclusions:
> > Quite any car is better for towing, in handling and safety than
> > a SUV.
> >
> > I prefer to rent a 4-wheel drive for holiday in the outback,
> > own a small car with common rail turbo diesel engine
> > (2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
> > per 100km consumption).
> > Like that I can pay many tows with the saved money I do not
> > spend on petrol.
> > I can tow any trailer with brakes up to 1500kg stable with
> > 100km/.
> > And on a windy road the SUV just disappear in the rear mirror.
> > But I cannot compete offroad with these monsters. I don't mind
> > because I only need offroad function perhaps 7 days a year.
> > How often do you need offroad capability?
> > Think of it when you buy the next car.
> > Chris
> >
> >
> > "chris" > wrote in message
> > om...
> > > Several people have had good luck towing a glider with a Subaru
> > > Forester.
>
> > > My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> > > is stable, and if you push sideways it does not sway side to side
> > > anywhere near the degree that the Forester does. Steering response
> > > and cornering are good.
>
> > > Chris Ruf
> > >
> >
> >
So, pulling anything at 55-65 mph should be fairly safe. What I
want to see is pulling a trailer beyond the rating of a
vehicle-happens more than it should. Yes, many might have an suv but,
given the situation of having to get somewhere where there are
actually grades to climb and areas of less than perfect roads, an suv
is useful. I own one and have used it several times on a "retrieve"
without having to worry about where I'm going.
Personal choice is acceptable in both driving and soaring.

[JohnD]

I have a Chev. Tahoe 4x4 and it pulls my trailer very, very well thank
you. At 75mph going up 395 to Bishop it doesn't sway much at all. When
I need to pass a motorhome (caravan)I can accelerate and pass with in
a minimum of time and maximum of safety. When there are cross-winds on
the trip I have the knowledge that I will be directing it down the
road rather than the other way around. Anyone who believes it is ok to
pull a trailer with a car that is smaller and lighter has never been
in a serious wind situation in the western U.S.

It has great ground clearance and if I land somewhere where it can't
get me, well I had better just hire a helicopter. I also use it to
pull my tent trailer off road in Baja California fully loaded with
dive gear, water, etc. Same story. Over the dunes onto the beach
campsites. I think I will leave the Civic to the people who want to
dodge 18 wheelers on the freeway in the city. Of course I DO have a
winch on it, just in case.

Hopefully our politicians will allow us the same freedom of choice for
vehicles as they want us to have for sex! (that wasn't well put, but
you get the message).

I do not support terrorists.

(Larry Johnson) wrote in message >...
> "szd41a" > wrote in message >...
> > Bingo!!!
> > I never had a better ride puliing my glider-trailer than with My Honda Civic
> > (90 H.P). Drove it all the way from Montreal to the ridge in Pensylvania, up
> > the steep mountain roads of Lake Placid, or Sugarbush, many outlandings and
> > 800 km drives to the repair shop. Very steady drive at 110 km/h. I had this
> > car for eleven years, and I miss my Civic sinceI bought a new car with more
> > horse power, and a higher c.g. !!!! I guess you want the shortest distance
> > between rear axle and hitch point (obviously) and the lowest c.g (automobile
> > engeneering is regeressing) and also all what is mentioned below. It amazes
> > me mucho to see all theese people driving SUV thinking they are safer!!!
> > BQ
> > "CH" > a écrit dans le message de
> > ...
> > > I don't know how long it does take for certain people
> > > to recognise, that SUV's and 4-wheel drive cars
> > >
> > > - are built for use in the outback and not for driving in towns
> > > - have a high CG and are handling worse on windy roads than
> > > any normal cars with good suspension (European/Japan cars)
> > > - have big tires to suit off road driving, which are worse on
> > > normal roads, worse than normal or low profile tires.
> > > - often do not have independent side stable suspension on the
> > > back which give them bad side stability (push the car sideways
> > > on the rear bumper and let it go - if the hole car swings around
> > > the vertical yaw axis then it does not suit towing)
> > > - have bad aerodynamics and produce more turbulence behind,
> > > which has again bad influence on the trailers stability.
> > >
> > > Conclusions:
> > > Quite any car is better for towing, in handling and safety than
> > > a SUV.
> > >
> > > I prefer to rent a 4-wheel drive for holiday in the outback,
> > > own a small car with common rail turbo diesel engine
> > > (2000 ccm, 110kW, 250Nm at 1750 rpm, and 4.5 to 6 liters
> > > per 100km consumption).
> > > Like that I can pay many tows with the saved money I do not
> > > spend on petrol.
> > > I can tow any trailer with brakes up to 1500kg stable with
> > > 100km/.
> > > And on a windy road the SUV just disappear in the rear mirror.
> > > But I cannot compete offroad with these monsters. I don't mind
> > > because I only need offroad function perhaps 7 days a year.
> > > How often do you need offroad capability?
> > > Think of it when you buy the next car.
> > > Chris
> > >
> > >
> > > "chris" > wrote in message
> > > om...
> > > > Several people have had good luck towing a glider with a Subaru
> > > > Forester.
>
> > > > My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
> > > > is stable, and if you push sideways it does not sway side to side
> > > > anywhere near the degree that the Forester does. Steering response
> > > > and cornering are good.
>
> > > > Chris Ruf
> > > >
> > >
> > >
> So, pulling anything at 55-65 mph should be fairly safe. What I
> want to see is pulling a trailer beyond the rating of a
> vehicle-happens more than it should. Yes, many might have an suv but,
> given the situation of having to get somewhere where there are
> actually grades to climb and areas of less than perfect roads, an suv
> is useful. I own one and have used it several times on a "retrieve"
> without having to worry about where I'm going.
> Personal choice is acceptable in both driving and soaring.

[Bruce Greeff]

Now that is a sensible argument for having the big lump. I just fail to
understand the "bigger is always better" argument.

I most situations that the average driver experiences - an SUV or "full
size" sedan is more liability than advantage. At least the guy with the
compact sedan can dodge the 18 wheeler - in something as nimble as the
agerage big SUV it comes down to trying to intimidate your way on the
road. Problem is that does not work with the average 18 wheeler (at
least where I come from) Fact is that these jobs are less safe, less
economical and more work to drive in most situations. I know the average
US male has never had the opportunity to experience the convenience of
driving a spacious, comfortable and compact car.

If you have a situation that justifies the inconvenience - like having
real need of off road capability - drive the SUV. If you can afford it,
as a couple of my friends can, have the SUV for when you need it and a
more practical vehicle for the commute. (As an extreme - one member at
our club drives a 2ton Landrover Discovery for gliding and
mountaineering, and Scuba expeditions, but commutes in a Mini Cooper S)

Whatever works for you. I just fail to understand those who have to
justify emotional / ego / social purchases by somehow trying to
construct a reasoned argument for why bigger is better. If you take that
to it's logical conclusion you should be buying Peterbilt (Or Mercedes,
or Renault...) horses for commuting in- I mean there is no shortage of
power, leather upholstery, aircon, air suspension, power everything, and
the best thing is you don't have to dodge the 18 wheelers, you are on
their level so to speak.

For what it is worth I have driven military 10ton 6 wheel drives through
Damaraland in Namibia - really needed the traction, power and ground
clearance, especially in case we hit a landmine, but I would hate to put
this on my list of fun vehicles to drive. Also driven all over South
Africa in ordinary sedans and MPVs, most with front wheel drive. Towed
retrieves with vehicles ranging from a Jeep Cherokee, to a 1600 hatch.
Have to say that for comfort, safety, good stability and everyday
convenience the best I have met is a small MPV. The current crop has
adequate power, excellent aerodynamics for stability in those windy
situations and certainly beats driving a truck all day.

Problem is the US carmakers can't make small cars profitably, SUVs are
very profitable because they are made on cheaper "truck" platforms. Once
again we have the victory of marketing and corporate profit over common
sense.

[Tim]

Cheers!

I've decided that the combination isn't the best.

So do I trade the 20 for a PW5? Or do I sell the wife and get a Mondeo
????


Decisions, decisions.....

"tango4" >s comments read:

>Tim
>
>You are truly a SIFOW proponent. An 1100cc 106 and an ASW20 is an impressive
>combination! I salute you sir!
>
>Ian
>
>
>"Tim" > wrote in message
...
>> "tango4" >s comments read:
>> >
>> >Ian - 2300cc ( petrol I will admit ) Ford MPV and about 53 kgs tongue
>weight
>> >a proven 100mph combination!
>>
>> Ian a proven TINSFOS man
>>
>> Tim - Peugeot 106 1100cc
>> A legal 60mph combination ;)
>>
>> --
>> Tim - ASW20CL "20"
>

--
Tim - ASW20CL "20"

[Chris OCallaghan]

Ah yes... well, God grants one, hard work the other. At least I can
wrap myself in a metaphor.

"Simon Waddell" > wrote in message >...
> Yes - but I find that SIZE, POWER and TRACTION of the p***s always excites
> more envy and desire than that of 7000 lbs of Detroit p***s substitute.
>
>
> "Chris OCallaghan" > wrote in message
> om...
> > 100kph? Do you drive backwards on retrieves for sport? Or perhaps you
> > always land close enough to the airport that there's no hurry...
> >
> > Sing what praises you may, they echo hollow among the leather clad
> > comforts of my 7000 lbs of 4x4 SUV... the best you can achieve with
> > your little brand-name putt-putt is "adequacy." If you want to excel,
> > be the envy of every man and the desire of every woman, there's no
> > substitute for SIZE, POWER, and TRACTION.
> >
> > But fear not, I'm sure you'll find friends for whom "adeqaute" is
> > enough.

[Graeme Cant]

Tim wrote:
> Cheers!
>
> I've decided that the combination isn't the best.
>
> So do I trade the 20 for a PW5? Or do I sell the wife and get a Mondeo
> ????

Post photos of all four and we'll help you decide. :)

GC

[Kevin Neave]

Stick with the 20, fly PW5 tasks, then you won't ever
land out & won't need to tow at all!

At 12:12 29 September 2003, Graeme Cant wrote:
>Tim wrote:
>> Cheers!
>>
>> I've decided that the combination isn't the best.
>>
>> So do I trade the 20 for a PW5? Or do I sell the wife
>>and get a Mondeo
>> ????
>
>

[Graeme Cant]

Bruce Greeff wrote:
> Now that is a sensible argument for having the big lump. I just fail to
> understand the "bigger is always better" argument.
>
> I most situations that the average driver experiences - an SUV or "full
> size" sedan is more liability than advantage. At least the guy with the
> compact sedan can dodge the 18 wheeler...

How about the 34-wheeler, 42-tonne, B-double passing you at 110k on a
narrow, single lane road in a 30knot crosswind gust at the top of the
Great Dividing Range? Or a road train with 500 sheep on it? The guy in
the Civic can have his nimble, comfortable, economical car but he'll
scare himself witless and it'll nimble him right off the road with the
blast from the truck. Cars are just the same as aeroplanes. More
nimble = less stable.

I prefer two and a half tonnes with under a metre from towball to back
axle. They don't take crap from glider trailers and they don't get
blown off the road.

- in something as nimble as the
> agerage big SUV it comes down to trying to intimidate your way on the
> road. Problem is that does not work with the average 18 wheeler (at
> least where I come from) Fact is that these jobs are less safe, less
> economical and more work to drive in most situations. I know the average
> US male has never had the opportunity to experience the convenience of
> driving a spacious, comfortable and compact car.

Wow!! I didn't know so many prejudices could co-exist in one small
jaapie - and all at the same time!

> If you have a situation that justifies the inconvenience - like having
> real need of off road capability - drive the SUV.

I drove mine 2 kms to the shops today on a smooth bitumen road. It was
quiet, smooth, relaxing - and with its 6-stacker, I could play both
kinds - country AND western! Last week I drove 800kms a day for a
couple of days with a two-seater glider behind. It was still quiet,
smooth, relaxing AND the music was just as good! How can that be
inconvenient?

Get your hands above the desk, Bruce baby.

> ...If you can afford it,
> as a couple of my friends can, have the SUV for when you need it and a
> more practical vehicle for the commute. (As an extreme - one member at
> our club drives a 2ton Landrover Discovery for gliding and
> mountaineering, and Scuba expeditions, but commutes in a Mini Cooper S)
>
> Whatever works for you.

Ah! That sounds a bit more tolerant.

>...I just fail to understand those who have to
> justify emotional / ego / social purchases by somehow trying to
> construct a reasoned argument for why bigger is better. If you take that
> to it's logical conclusion you should be buying Peterbilt (Or Mercedes,
> or Renault...) horses for commuting in- I mean there is no shortage of
> power, leather upholstery, aircon, air suspension, power everything, and
> the best thing is you don't have to dodge the 18 wheelers, you are on
> their level so to speak.

No, Bruce, that's dopey. All anyone said was that a 1 1/2 tonne glider
trailer is best controlled by something a little larger than it is. 2
1/2 stable tonnes will do fine. If you want to do it (tow) with a
little car, go ahead, but you'd be much more relaxed, comfortable, safe
and in control in my 4WD.

> For what it is worth I have driven military 10ton 6 wheel drives through
> Damaraland in Namibia - really needed the traction, power and ground
> clearance, especially in case we hit a landmine, but I would hate to put
> this on my list of fun vehicles to drive. Also driven all over South
> Africa in ordinary sedans and MPVs, most with front wheel drive. Towed
> retrieves with vehicles ranging from a Jeep Cherokee, to a 1600 hatch.
> Have to say that for comfort, safety, good stability and everyday
> convenience the best I have met is a small MPV. The current crop has
> adequate power, excellent aerodynamics for stability in those windy
> situations and certainly beats driving a truck all day.

Well, Brucie, we can all claim our experience. After 40 years towing
all over Oz, here's mine in a nutshell: I've towed with big and I've
towed with small and believe me big is better (with apologies to Pearl
Bailey(?)).

> Problem is the US carmakers can't make small cars profitably, SUVs are
> very profitable because they are made on cheaper "truck" platforms. Once
> again we have the victory of marketing and corporate profit over common
> sense.

Now, Bruce, watch those prejudices! They sneak out and show your true
colours just when you're sounding all pompous and solemn. :)

GC

[Eric Greenwell]

In article >,
says...
>Cheers!
>
>I've decided that the combination isn't the best.
>
>So do I trade the 20 for a PW5? Or do I sell the wife and get a Mondeo
>????

How about a SparrowHawk instead? Unless it's World Class competition you
are interested in, you'll find it has higher performance and lower
weight. The glider is about 160 pounds, and with their composite trailer
and the usual stuff in it, you're looking a less 1000 streamlined pounds
(453 kg). You could tow with the original Mini!
--
-----
Eric Greenwell USA

[Bruce Greeff]

Hi Graeme

Lots of prejudices here mate, sorry if I offended.

Maybe it is a SIFOW thing, I prefer not driving trucks.

Again each to his own.

[Alex Chappell]

As long as it's stable who cares?
I know people who have walked away from pretty scary
accidents - punctures at speed limit whilst towing
on dual carriageway and the like - when it has been
a sensible, well behaved combination, SUV or otherwise.
Equally, there are combinations which are just an
accident waiting to happen. Once it gets out of control,
the soggy suspension and high C of G just make an SUV
dead easy for the trailer to flip, however heavy it
is (ever watched wrestling?)
Light cars are easily steered by big trailers.

Don't know about in the US, but here in the UK you
could probably put all trailer smashes down to one
of three things:

1. lightweight cars with a large distance betweeen
the rear axle and hitch. Plenty of these around here.
The trailer does the steering especially if it is heavy.

2. Rogue trailers. Most trailers are perfectly OK towed
within the limits. Some change dramatically between
empty and loaded. I remember a ? homebuilt two-seater
trailer which loaded was a nightmare and empty was
almost impossible. I know of trailers which use old
caravan suspension components or car tyres, which are
almost always not stiff enough. Get one of these on
an SUV and it would be interesting.


3. Bad driving.Self explanatory.

Have a nice day

Al

At 16:12 29 September 2003, Bruce Greeff wrote:
>Hi Graeme
>
>Lots of prejudices here mate, sorry if I offended.
>
>Maybe it is a SIFOW thing, I prefer not driving trucks.
>
>Again each to his own.
>
>

[JJ Sinclair]

CHRIS WROTE>>>>>>>>>>>>>...
> Mine is a
>nightmare. It is unstable above 50mph. It has a lot of side to side
>sway above 50mph if there is any steering input. It is almost
>harmonic in nature – it does not dampen out quickly. If feels like
>you are driving on Jello.

There was a lot said on the *Komet Trailer Fin* causing instability, about a
year ago. I typed in *Komet Trailer* into Google and found a good report by,
Dan Dunkel. He was able to tame the beast by adding turbulators on each side of
his trailer fin. This report is on page 3 of Google, under Komet Trailer.
Hope this helps,

JJ Sinclair

[Tom Seim]

Amen to the Tahoo. I just bought my second one. Calling the Civic a
safe tow vehicle is like saying a 12 ft row boat is OK for the north
Atlantic. I've seen enough crumpled trailers & tow cars along side the
roadway to know that my butt is worth the extra price of the Tahoe.
You other guys can take your chances for all I care. I just hope I
don't find your crumpled mess along the way (but at least you know
you've save a few bucks on gas).

Tom Seim
Richland, WA

[chris]

(JJ Sinclair) wrote in message
> There was a lot said on the *Komet Trailer Fin* causing instability, about a
> year ago. I typed in *Komet Trailer* into Google and found a good report by,
> Dan Dunkel. He was able to tame the beast by adding turbulators on each side of
> his trailer fin. This report is on page 3 of Google, under Komet Trailer.
> Hope this helps,
>
> JJ Sinclair

JJ,

Last year I installed the turbulator strip on my Komet fin. It is
about .75" [19mm] high and about 3" [75mm] back from the front of the
fin. [aluminum extrusion]. It has made a very noticeable difference,
and stablilzed the trailer at higher speeds, especially behind the
disturbed flow of 18wheel trucks. This cured an aerodynamic problem
that felt aerodynamic.

I also did a short test drive with the rear hatch of the Forester
open. This should have significantly altered the airflow between the
tow vehicle and the trailer. This had no impact on the swaying issue.
The swaying issue begins with a steering input, does not appear/feel
to be aerodynamic in nature. [And even if it were the Forester does
not seem to have much steering response on these tires to counteract
the motion].

Also the swaying starts at about 45mph [72km/h] which is low for this
much force to be generated aerodynamically.

Thanks for the feedback,
Chris

[JJ Sinclair]

Chris wrote>>>>>>>>>>>>>>>>>>>>
>Also the swaying starts at about 45mph

Have you tried adding shock absorbers? Don't jump my sierra, if this has been
covered, I haven't been following along. I had a utility trailer that would
sway so much I was afraid it would dump its load, adding shocks did the trick.


JJ Sinclair

[Bill Daniels]

"chris" > wrote in message
om...
> (JJ Sinclair) wrote in message
> > There was a lot said on the *Komet Trailer Fin* causing instability,
about a
> > year ago. I typed in *Komet Trailer* into Google and found a good report
by,
> > Dan Dunkel. He was able to tame the beast by adding turbulators on each
side of
> > his trailer fin. This report is on page 3 of Google, under Komet
Trailer.
> > Hope this helps,
> >
> > JJ Sinclair
>
> JJ,
>
> Last year I installed the turbulator strip on my Komet fin. It is
> about .75" [19mm] high and about 3" [75mm] back from the front of the
> fin. [aluminum extrusion]. It has made a very noticeable difference,
> and stablilzed the trailer at higher speeds, especially behind the
> disturbed flow of 18wheel trucks. This cured an aerodynamic problem
> that felt aerodynamic.
>
> I also did a short test drive with the rear hatch of the Forester
> open. This should have significantly altered the airflow between the
> tow vehicle and the trailer. This had no impact on the swaying issue.
> The swaying issue begins with a steering input, does not appear/feel
> to be aerodynamic in nature. [And even if it were the Forester does
> not seem to have much steering response on these tires to counteract
> the motion].
>
> Also the swaying starts at about 45mph [72km/h] which is low for this
> much force to be generated aerodynamically.
>
> Thanks for the feedback,
> Chris

My Komet trailer has the aluminum spoilers on the fin and it seems to tow
well up to 75MPH - unless there is a sharp steering input like Chris says.
My feeling is that the problem is suspension/tire related. I tow with a
Jeep Grand Cherokee and below 65 MPH the handling is perfect.

I'm pretty sure that the problem is with the Jeep. (Despite remarks to the
contrary, the older Jeep Grand Cherokee (ZJ) is a lightweight among the
current crop of SUV's and not much heavier than the Forester.) I've had
similar but worse problems towing other trailers.

I deliberately started the sway on an empty stretch of interstate highway
and observed that the trailer sways back and forth rotating about the
vertical axis while the Jeep rolls side to side rotating about the
longitudinal axis. In other words the trailer fishtails while the towing
vehicle rolls back and forth. The period of the trailer's sway is the same
as the Jeeps natural roll frequency so there seems to be a destructive
resonance going on. The Jeep rolls in the direction of the travel of the
front of the trailer which suggests that the Jeeps roll center is much lower
than the tow hitch. Lowering the tow ball is not an option for ground
clearance reasons so increasing the Jeep's roll stiffness seems a good way
to go.

So far, I've increased the Jeep's tire pressure up to the point that the
ride is too stiff for comfort and, while it does help, that's not the
solution I want because of the harsh ride. The next try is to replace the
13mm stock rear sway bar with a 25mm diameter ADDCO bar. Since the
handling with the trailer is really quite good below 65 MPH, this is not a
high priority issue with me since slowing down saves a lot of fuel anyway.

Bill Daniels

[Jose M. Alvarez]

Definite.
Mondeo and ASW-20
Wonder why you ever had a doubt.

"Tim" > escribió en el mensaje
...
> Graeme Cant >s comments read:
>
> >Tim wrote:
> >> Cheers!
> >>
> >> I've decided that the combination isn't the best.
> >>
> >> So do I trade the 20 for a PW5? Or do I sell the wife and get a Mondeo
> >> ????
> >
> >Post photos of all four and we'll help you decide. :)
>
> ASW20
> http://www.gliderforum.com/photos/show-album.asp?albumid=59&currentpos=3
>
> PW5
> http://www.hotornot.com/r/?eid=N8KRKES&key=WPU
>
> Wife
> http://my.tenforward.com/rozebud/button/2/kysmy.jpg
>
> Mondeo
> http://www.tiscali.co.uk/motoring/roadtests/roadtest_14_1.html
>
> So what do you think?
> --
> Tim - ASW20CL "20"

[Graeme Cant]

chris wrote:
> ...This had no impact on the swaying issue.
> The swaying issue begins with a steering input, does not appear/feel
> to be aerodynamic in nature. [And even if it were the Forester does
> not seem to have much steering response on these tires to counteract
> the motion].
>
> Also the swaying starts at about 45mph [72km/h] which is low for this
> much force to be generated aerodynamically.

I owned a Forester for a short time a few years ago and I think the
steering is either over-assisted or inadequately self-centreing (or
both!). I suppose you'd say the force gradient is too flat. Whatever
the cause, it always seemed to me to be too sensitive to small inputs.
Unless I rested at least one elbow, the car would readily set up a
slight wander from side to side. It was easy to set up a rhythmical
roll which had very little natural damping even with no trailer
attached. It would drift off line easily with a moment's inattention.

The tyres were probably Bridgestones but I can't be sure now. They
certainly weren't low profile - probably 75-80 (this was the unblown 2
litre - not the GT)

I towed a Blanik about 800kms with the Forester. I certainly didn't
have chris's problems - I drove happily at speeds up to 110km/h with no
trailer instability but I remember it wasn't a relaxing drive and winds
did affect it. I recall carefully keeping my elbows on the armrests to
damp the steering. The drawbar load would have been about 60-70kg and I
followed the book on tyre pressures for max load.

My thought would be that the main problem is the trailer but it's
exacerbated by a car with sensitive steering and inadequate roll
damping. Check the drawbar load and suspension of the trailer first.
It's probably cheaper to move the trailer axle back than to change cars!

I'd agree with the guy who said boost the tyre pressure at the rear but
not the front. Stiffer rear roll bar would be useful. The GT version
probably has lower profile tyres and rims which would help - check if it
has a stiffer roll bar.

The Forester steering is similar to a SAAB I once owned. Audi are a bit
like it too. I think largish FWD cars tend to have dead, over-assisted
steering and Subaru is a 4WD which comes from a FWD tradition. 4WDs
which come from the other end - Land Cruiser, Land Rover - seem to have
better weighted steering and are less sensitive and more stable.

GC

[Eric Greenwell]

In article et>,
says...
>So far, I've increased the Jeep's tire pressure up to the point that the
>ride is too stiff for comfort and, while it does help, that's not the
>solution I want because of the harsh ride. The next try is to replace the
>13mm stock rear sway bar with a 25mm diameter ADDCO bar. Since the
>handling with the trailer is really quite good below 65 MPH, this is not a
>high priority issue with me since slowing down saves a lot of fuel anyway.

This stiffer bar will tend to move the handling towards oversteer (less
stable in turns) because it increases the load on the outside rear tire
in a turn. Be cautious checking out the handling, and be prepared to
also increase the size of the front sway bar to move the handling
towards understeer (more stable in turns).

--
-------
Eric Greenwell USA

[Deputy Dog]

Trailer tires can make a big difference also. In the USA, they are
noted as "ST" (special trailer) rated. My last cobra really swayed
bad until I changed the regular car radials (not cheap ones)on it for
"ST" rated tires.
Since they are made for trailers and thus non-steering, the sidewalls
are stiffer. They did the trick for me. My new cobra has european
radials and it does not do as well, but I've not gotten around to
changing
them. My tow vehicle is a 4WD Tahoe which is no lightweight. High CG
may account for some of the problem also. High quality
tires on the tow vehicle also make a difference.

I can't go along with advocating overinflation of the tires. Up to
the max. allowable yes, but beyond that you become the test driver.

-Deputy Dog


(RHWOODY) wrote in message >...
> This may be helpful - over inflate the
> rear vehicle tires - at least maximum
> pressure - leave the front vehicle tires
> at normal pressure (dampening) -
> and at least maximum pressure in the
> trailer tires - over inflation is better.
> This is the most stable configuration.
> Additionally, buy a couple 5 gallon
> canisters and fill them with water and
> place them in the front of the trailer.
> Good luck, and drive safe.

[JohnD]

Personal choice and the sensible matching of the tow vehicle to the
trailer is what it is all about.

I should explain that here in California where we are recalling our
Governor one of the over 140 candidates is placing tv ads stating that
if you drive an SUV you support terrorism. This candidate now also
supports the governor who made it legal for illegal immigrants to
obtain a drivers license. Go figure. Other people label SUV drivers as
antisocial. Give me a break. You can be just as 'antisocial' on the
road in a Civic as well as in a Tahoe; or flying a Ventus as well as a
PW5. So some of SUV drivers here are just a bit touchy about all that!

Alex Chappell > wrote in message >...
> As long as it's stable who cares?
> I know people who have walked away from pretty scary
> accidents - punctures at speed limit whilst towing
> on dual carriageway and the like - when it has been
> a sensible, well behaved combination, SUV or otherwise.
> Equally, there are combinations which are just an
> accident waiting to happen. Once it gets out of control,
> the soggy suspension and high C of G just make an SUV
> dead easy for the trailer to flip, however heavy it
> is (ever watched wrestling?)
> Light cars are easily steered by big trailers.
>
> Don't know about in the US, but here in the UK you
> could probably put all trailer smashes down to one
> of three things:
>
> 1. lightweight cars with a large distance betweeen
> the rear axle and hitch. Plenty of these around here.
> The trailer does the steering especially if it is heavy.
>
> 2. Rogue trailers. Most trailers are perfectly OK towed
> within the limits. Some change dramatically between
> empty and loaded. I remember a ? homebuilt two-seater
> trailer which loaded was a nightmare and empty was
> almost impossible. I know of trailers which use old
> caravan suspension components or car tyres, which are
> almost always not stiff enough. Get one of these on
> an SUV and it would be interesting.
>
>
> 3. Bad driving.Self explanatory.
>
> Have a nice day
>
> Al
>
> At 16:12 29 September 2003, Bruce Greeff wrote:
> >Hi Graeme
> >
> >Lots of prejudices here mate, sorry if I offended.
> >
> >Maybe it is a SIFOW thing, I prefer not driving trucks.
> >
> >Again each to his own.
> >
> >

[Eric Greenwell]

In article . net>,
says...
>Absolutely true Eric. Anyone contemplating such a modification should be
>quite careful.
>
>The Jeep GC comes stock with a 1.25" front bar and a .5" rear bar which
>results in extreme understeer. The word on the Jeep forums is that the
>ADDCO 1" rear bar improves on-road handling a lot while hurting the off-road
>capability a bit.

I just recalled that years ago I improved the handling of my '89 Dodge
Grand Caravan by adding a rear sway bar, because it had way too much
understeer. It didn't noticeably affect the stability while trailering,
or hurt the ride except for speed bumps taken diagonally. Let us know
how the bigger bar works out.
--
-------
Eric Greenwell USA

[Bill Daniels]

"Eric Greenwell" > wrote in message
t...
> In article . net>,
> says...
> >Absolutely true Eric. Anyone contemplating such a modification should be
> >quite careful.
> >
> >The Jeep GC comes stock with a 1.25" front bar and a .5" rear bar which
> >results in extreme understeer. The word on the Jeep forums is that the
> >ADDCO 1" rear bar improves on-road handling a lot while hurting the
off-road
> >capability a bit.
>
> I just recalled that years ago I improved the handling of my '89 Dodge
> Grand Caravan by adding a rear sway bar, because it had way too much
> understeer. It didn't noticeably affect the stability while trailering,
> or hurt the ride except for speed bumps taken diagonally. Let us know
> how the bigger bar works out.
> --
> -------
> Eric Greenwell USA

Way back when I was dabbling in sports car racing, there was a saying about
understeer and oversteer. They said that if a Jaguar (understeer) driver
lost control and went off the race course, he would make a hole in the
boundary fence rolling forwards. If a Porsche (oversteer) driver lost
control, he would go through the same hole in the fence the Jag made but
going backwards.

Bill Daniels

[tango4]

I hate you!

Ian

"Clint" > wrote in message
om...
> Bruce - forget the tow vehicle - have you seen the weather forecast
> for the weekend for the Free State. 32 deg C - Sunny. Considering they
> are predicting 5m/s thermals and 16000ft thermal tops for today and it
> is just 27 deg C - the weekend should be even better. Isn't it great
> that summer is almost here!! (Sorry to all those in the north who have
> a bleak winter to look forward to - maybe use the SUV to get through
> the snow to the ski resorts).
>
> Clinton
> LAK 12 (who needs a smallish SUV to tow the largest trailer out there
> - but also tow it with my 1.6 Golf)

[Tim]

I've wimped out ... and bought an Audi 80 Estate to tow with. So I've
still got the 106, the 20 and the wife ... now if I can make her buy
the 106 <eg>

"Jose M. Alvarez" >s comments read:

>Definite.
>Mondeo and ASW-20
>Wonder why you ever had a doubt.
>
>"Tim" > escribió en el mensaje
...
>> Graeme Cant >s comments read:
>>
>> >Tim wrote:
>> >> Cheers!
>> >>
>> >> I've decided that the combination isn't the best.
>> >>
>> >> So do I trade the 20 for a PW5? Or do I sell the wife and get a Mondeo
>> >> ????
>> >
>> >Post photos of all four and we'll help you decide. :)
>>
>> ASW20
>> http://www.gliderforum.com/photos/show-album.asp?albumid=59&currentpos=3
>>
>> PW5
>> http://www.hotornot.com/r/?eid=N8KRKES&key=WPU
>>
>> Wife
>> http://my.tenforward.com/rozebud/button/2/kysmy.jpg
>>
>> Mondeo
>> http://www.tiscali.co.uk/motoring/roadtests/roadtest_14_1.html
>>
>> So what do you think?
>> --
>> Tim - ASW20CL "20"
>

--
Tim - ASW20CL "20"

[chris]

Here is the feedback on my trailer towing problem.
I thought I'd make a detailed write up to share what I learned with
others.

I was waiting until I gave a real towing trip as proof that this fix
worked. I recently drove from Atlanta up to the Sequatchie Valley in
TN. This included highway driving as well as crossing Signal Mountain
on a steep winding road. The Forester XT now is a good safe tow
vehicle. The turbocharged engine is really powerful, during hill
climbs I had to downshift not because it was too weak, but because it
wanted to race up the hills.

As I suspected it was indeed the tires at fault. For some reasons
the auto manufacturers insist on pinching pennies and putting on lousy
tires when for ~$20 of cost to them they could impress their customers
with a much higher quality ride.

The original tires were Yokohama Geolander G900 P215/60 R16 94H.
These are really poor quality, I suspect that they are the very
minimum standard of the H speed rating. This is an all season tire.

I replaced them with Toyo Proxes TPT P225/55 R16 95V.
These are much higher quality overall, [as well as the ratings for
treadwear, temperature & traction]. The key was switching from poor
"H" to good "V" rated tires. This gave a much stiffer sidewall.
The tire size is also 10mm wider [225 vs 215 with a 5% shorter
sidewall 55 vs 60]. [2% net reduction in diameter].
The tread compound is also harder, more like a sports car tire.

All these changes eliminated the uncontrolled harmonic
swaying/fishtailing that I experienced when towing my trailer with the
tall tires on the tow vehicle. During normal driving the ride is
stiffer, this is fine with me, the cornering is much improved.


Years ago I read that every force your car generates, acceleration,
braking and cornering etc. is transmitted through the tires - don't
skimp, they are one of the most components of the vehicle.
My advice to others that are experiencing swaying:
Invest in good quality tires.
Upgrade the speed rating to get a stiffer sidewall. [from S or T to H,
from H to V]
Consider shortening the sidewall with a lower ratio.
Increase the tire pressure.

Other advice that helped included lowering the hitch position and
shortening the hitch to reduce the distance from the ball to the rear
axle. Tongue weight is critical, 150lbs, around 10% works for me.

ok, I'm done typing, lets go fly!
regards,
Chris



---------------------

Original message
Tire Stiffness & trailer swaying

Several people have had good luck towing a glider with a Subaru
Forester. I do not know why mine is different.
I just bought a 2004 Forester tried to tow with it. Mine is a
nightmare. It is unstable above 50mph. It has a lot of side to side
sway above 50mph if there is any steering input. It is almost
harmonic in nature - it does not dampen out quickly. It feels like
you are driving on Jello. It feels like the problem is much more the
tires than the suspension. Though that is hard to prove.

Even when parked if you push on the hitch with your foot the Forester
will sway side to side [right and left] a lot. You can watch the rim
move right and left in and out of the tire. I think the sidewalls are
just really weak. The tread is probably relatively soft also.

The Forester's tires are Yokohama Geolander G900 P215/60 R16 94H.
Even in normal driving the steering response and cornering are poor.
[Other Foresters may be equipped with 15" tires, and other models of
Geolander tires - rather than the G900].

My Mazda MX-6 [much lower car] has Pirelli P4000 P205/55 R15 87H - it
is stable, and if you push sideways it does not sway side to side
anywhere near the degree that the Forester does. Steering response
and cornering are good.

The Geolander G900 has a tall soft sidewall, it is 4.500" above the
rim rather than 3.625" for the P4000 [24%higher].

My best idea right now is to change to a shorter and stiffer sidewall
tire.
I am considering changing from P215/60 R16 94H
- an "H" rate tire with 60% width/height ratio, to
Bridgestone Turanza LS-V 225/50R16 92V - this is a V rate tire so the
sidewall is stiffer and at a 50 or 55 ratio it is shorter.
This is the V rated version of the tire that some other Forester
owners have [LS-H]. The tread should also be a harder sports car like
compound.



Some of these tires are rated and discussed on www.tirerack.com. It
seems that Steering response and cornering stability are good
expressions of my issue.
On tirerack there are a mass of good comments on the Turanza tire -
though I doubt anyone is towing. As far as I can tell everyone on
"tirerack" hates the geolander 900 like on mine.


Does anyone else have any Experience changing to a shorter V rated
tire for better stability?


My trailer does great and stable to 85+mph behind my Mazda MX-6, so I
do not think it is the trailer. The trailer is a 1979 Komet with a
Mosquito. It weighs ~1800lbs [816kg]. The tongue weight is 153lbs
[69kg]. The Forester's manual says to keep the tongue weight between
8-11% of the trailer. 8%=144lbs [65kg] 11%=198lbs [90kg].
[the max allowed is 200lbs on the tongue] The manual transmission
version of the Forester is rated for 2400lbs [1088kg] towing capacity.


I have already tried raising the tire pressure on the rear tires to
41psi [2.8bar] as recommended by the manual. The trailer tires are
about 40psi.



Since my original write up I have learned the following:
The dealer told me that the 2004 model is the first to be equipped
with the Geolander G900 tires, previous years had a different model
tire. This is the only change to the suspension that he is aware of
between the 2002 and 2003/2004 model.

The Maximum tire pressure on the tires is 44psi, so I upped the rear
pressure to 44psi and the fronts to 41. [for towing the manual says
29psi front, 41psi rear]. I also changed the hitch from a straight
one to a "drop hitch" it is now 1.5" lower than the straight one.
The drop hitch is about 4.0" shorter than the "lift hitch" [bent
receiver hitch] that I originally tried. The hitch ball is on a short
receiver.
A test drive showed that the lower hitch/ball placement and the higher
tire pressures are an improvement. However still not acceptable. I
think the higher pressure stiffened the tires but not enough and the
tread is still too soft.

I have heard another Forester owner has had good luck with 75-100lbs
of tongue weight. An additional test drive was done after I moved
several items out of the front of the trailer to the back of the
Forester. This reduced the tongue weight to 118lbs [down 35lbs from
153]. The swaying seemed worse with the lower tongue weight. [This
follows the logic I have heard many times].

Chris Ruf