Do trailers with coil springs and shock absorbers sway at higher speeds?

[son_of_flubber]

My Avionic trailer has leaf springs and no shocks and the rhythmic ass end sway that develops at higher speeds encourages me to keep the top speed at 60-65 mph. That speed is just fine with me except when interstate traffic if flying by at 80 mph. In that case I feel that I'm something of a hazard, especially if I'm trying to merge or change lanes.

I'm thinking that shocks might dampen out the rhythmic sway that seems to be self-reinforcing. Tow vehicle is 2004 Volvo XC70. Single seat glass glider.

[[email protected]]

On Friday, June 6, 2014 6:44:32 PM UTC-4, son_of_flubber wrote:
> My Avionic trailer has leaf springs and no shocks and the rhythmic ass end sway that develops at higher speeds encourages me to keep the top speed at 60-65 mph. That speed is just fine with me except when interstate traffic if flying by at 80 mph. In that case I feel that I'm something of a hazard, especially if I'm trying to merge or change lanes.
>
>
>
> I'm thinking that shocks might dampen out the rhythmic sway that seems to be self-reinforcing. Tow vehicle is 2004 Volvo XC70. Single seat glass glider.

If you see rolling associated with the motion,damping might help. I doubt that to be the case.
This topic has come up several times.
Easy improvements are:
Get any weight you can out of the back of the trailer.
Check your tires to see that they are properly inflated. Stiffer side walls that result from somewhat higher pressure sometimes helps.
One guy I know put "trip strips" on the leading edge of the dog house on his Avionic trailer and claimed it made a big difference. Color me skeptical but it may work.
UH

[Bob Kuykendall]

On Friday, June 6, 2014 3:44:32 PM UTC-7, son_of_flubber wrote:
> Tow vehicle is 2004 Volvo XC70. Single seat glass glider.

Every time I've had the problem you describe, the solution has been one of the following:

* Fix the suspension of the tow car. New shock absorbers, and replacement of any worn or crumbling suspension bushings. And, trust me, the AWD versions of the Volvo P2 chassis cars have plenty of opportunities for those. My next snow car is definitely gonna be a Subaru; I'll take a head gasket change over that clusterfutzery any day.

* Lengthen the trailer tongue. Glider trailer tongues are way too often too short; sometimes an extra 4" or so will make a huge difference in stability.

Thanks, Bob K.

[[email protected]]

On Friday, June 6, 2014 6:44:32 PM UTC-4, son_of_flubber wrote:
> My Avionic trailer has leaf springs and no shocks and the rhythmic ass end sway that develops at higher speeds encourages me to keep the top speed at 60-65 mph. That speed is just fine with me except when interstate traffic if flying by at 80 mph. In that case I feel that I'm something of a hazard, especially if I'm trying to merge or change lanes.
>
>
>
> I'm thinking that shocks might dampen out the rhythmic sway that seems to be self-reinforcing. Tow vehicle is 2004 Volvo XC70. Single seat glass glider.

My Komet swayed at highway speeds after weight was taken out of the front of it and items were also moved to the rear of the trailer. Shifted items back to the front and added about 25 pounds of weight to the front and swaying stopped at highway speeds. Previous owner had similar observations.

[Bill T]

Trailer weight is too far aft. Our Komet trailer with LS4 tows fine at highway speeds behind my old Ford Ranger and my newer Toyo Tundra Gen2.
We had that problem towing an empty Cobra Grob 103 trailer until we put a couple of tool boxes and spare tires in the front. Towed just fine with a 103 inside.
Factory Grob 103 trailer towed really bad with a glider inside. It took a lot of weight at the front end of the trailer to settle down.

BillT

[Vernon Brown]

Its always a good idea to fit Shock Absorber, if you have ever follow a
Glider trailer without shocks you can see the way trailers dance and move
about on any surface that’s less than perfect.
Proper loading of the trailer is very important as been said before,
another issue is crabbing, the trailer should run straight, check to see
that axle and tow hitch is true.

Vernon.


At 04:50 07 June 2014, Bill T wrote:
>Trailer weight is too far aft. Our Komet trailer with LS4 tows fine at
>highway speeds behind my old Ford Ranger and my newer Toyo Tundra Gen2.
>We had that problem towing an empty Cobra Grob 103 trailer until we put a
>couple of tool boxes and spare tires in the front. Towed just fine with a
>103 inside.
>Factory Grob 103 trailer towed really bad with a glider inside. It took a
>lot of weight at the front end of the trailer to settle down.
>
>BillT
>

[glidergeek]

Longer wheelbase tow vehicle

[Dan Daly[_2_]]

On Friday, June 6, 2014 6:44:32 PM UTC-4, son_of_flubber wrote:
> My Avionic trailer has leaf springs and no shocks and the rhythmic ass end sway that develops at higher speeds encourages me to keep the top speed at 60-65 mph.

When I got my Avionic trailer in 2009, I got the shocks as a 110Euro option - it is very well-behaved at speed - no sway. I tow with a Jetta TDI (7 l/100km - 32 mpUSg at 65 mph). Well worth the money. I'd check with windpath to see if they can be retrofit. Small price considering what's in the trailer.

2D

[Nick Kennedy]

Trailers are funny beasts, especially long trailers.
Shocks are important items as is using real trailer tires if your having problems; Trailer tires have stiffer sidewalls to help with the sway.
Make sure they are at max pressure.
The trailer C.G. is also very important; the C.G. must be well ahead of the axle, this where tongue weight comes into play. The tongue has to be heavy; how heavy? heavy enough to minimize the sway effect.
If you cannot picture this CG thing draw a picture of a trailer and move the CG ball aft of the axle and think about the CG being back there...When it starts moving back and forth it wants to go divergent, not good.
My Cobra trailer came with two large sandbags in the front of it and I cram all I can into the front storage space, self rigger, tow out gear etc and bungee it all down.
Flub, try and find a old school trailer man in your area, I bet he could look and your rig and have a solution.

[[email protected]]

Been towing gliders for some time.
Tongue weight is number one. You want significant forward CG in trailer.
Stiff sidewall tires is number two. Get trailer tires. Not car tires.
Keep it under 80mph.

[Dan Marotta]

Trailer, not glider, but...

Last week my wife and I were towing our utility trailer with two 17'
kayaks on the interstate. I've also been carrying 3 5-gallon cans of
water up front in the trailer as ballast. Last week one of the cans
developed a leak and suddenly, at 75 mph, the trailer began to sway
violently left to right. Slowing down to 60 mph would make the swaying
stop, but that's dangerous out west. So - first exit we got off and
loaded a bunch of rocks in the front of the trailer. Problem solved!

Dan Marotta

On 6/7/2014 7:39 PM, wrote:
> Been towing gliders for some time.
> Tongue weight is number one. You want significant forward CG in trailer.
> Stiff sidewall tires is number two. Get trailer tires. Not car tires.
> Keep it under 80mph.

[[email protected]]

There are three Avionics owned by members of my club. They all have the torsion type axle and tow quite nicely. Mine (a 2004) was not quite as good as the other ones though until I put 175 size tires on it in place on the 165's it came with. The newer ones came with 175's from the factory.

Shocks certainly wouldn't hurt but the suggestions about increasing the tongue weight are worth following. It may make a significant improvement and would be easy and inexpensive to try.

Trailer stability is weird though. The Pfeister trailer my club has for a Twin Astir has almost no tongue weight when loaded but towed nicely behind my old Nissan pickup. Once, when taking it through the Rockies it had been loaded the "proper" way by the club expert - he put ballast right up front so it had about 100 pounds tongue weight. Loaded like that it tried to throw me off the road at anything above 75 KMH towed by the same truck. Go figure.

[[email protected]]

On Wednesday, June 11, 2014 4:53:40 AM UTC-4, wrote:
> There are three Avionics owned by members of my club. They all have the torsion type axle and tow quite nicely. Mine (a 2004) was not quite as good as the other ones though until I put 175 size tires on it in place on the 165's it came with. The newer ones came with 175's from the factory.
>
>
>
> Shocks certainly wouldn't hurt but the suggestions about increasing the tongue weight are worth following. It may make a significant improvement and would be easy and inexpensive to try.
>
>
>
> Trailer stability is weird though. The Pfeister trailer my club has for a Twin Astir has almost no tongue weight when loaded but towed nicely behind my old Nissan pickup. Once, when taking it through the Rockies it had been loaded the "proper" way by the club expert - he put ballast right up front so it had about 100 pounds tongue weight. Loaded like that it tried to throw me off the road at anything above 75 KMH towed by the same truck. Go figure.

A very significant factor, mentioned by Bob above, is the vehicle and the quality of suspension and tires on the vehicle.
Generally said, a vehicle that handles very well, with good tires properly inflated, should be a decent tow machine.
It is important to not have the trailer tail heavy, but over loading the tongue on a bad vehicle- trailer combination won't solve much and can make a poor combination worse. Old tires and suspension, with low air pressures, and maybe some extra overhang on the tow hitch,and a really heavy tongue, will make a very uncomfortable situation.
Moving some heavy crap out of the trailer and into the tow vehicle, between the axles can make startling improvement in some cases.
Jaguar XJ6 towing Cobra trailer, is the best combination I ever used. Solid, comfortable, and safe at any speed you would want to drive the car. But not a desert rig. Never had more than 75 lb on the tongue.
UH

[Mike the Strike]

My 2001 Cobra trailer arrived from the previous owner with lead weights and dumbbells at the front to increase tongue weight. I removed them and found still plenty of tongue weight and no towing instability behind a Toyota 4Runner at speeds up to 85 mph (Arizona highway speed!) I replaced the tires last year with recommended trailer tires and have absolutely no problems except in very strong gusty side-winds, when I slow to 70 mph.

I suspect the geometry and suspension of the tow vehicle are an important part of the equation - I have always used robust, heavy four-wheel drive vehicles designed for towing and have never experienced severe instability problems.

Mike

[Papa3[_2_]]

On Wednesday, June 11, 2014 8:33:32 AM UTC-4, wrote:
> On Wednesday, June 11, 2014 4:53:40 AM UTC-4, wrote:
>
> A very significant factor, mentioned by Bob above, is the vehicle and the quality of suspension and tires on the vehicle.
>
> Generally said, a vehicle that handles very well, with good tires properly inflated, should be a decent tow machine.
>
> It is important to not have the trailer tail heavy, but over loading the tongue on a bad vehicle- trailer combination won't solve much and can make a poor combination worse. Old tires and suspension, with low air pressures, and maybe some extra overhang on the tow hitch,and a really heavy tongue, will make a very uncomfortable situation.
>
> Moving some heavy crap out of the trailer and into the tow vehicle, between the axles can make startling improvement in some cases.
>
> Jaguar XJ6 towing Cobra trailer, is the best combination I ever used. Solid, comfortable, and safe at any speed you would want to drive the car. But not a desert rig. Never had more than 75 lb on the tongue.
>
> UH

Quick and timely corroboration of the above. I sold my LS8 with 1990 Komet Euro Light trailer last week. Incredibly well behaved rig behind anything that's towed it over the last 14 years (Sprinter Van, Honda Odyssey, VW Sportwagen TDI). New buyer got only a few miles down the road on Interstate 95 before calling to ask about significant sway at highway speeds. What changed: 1) the tow vehicle 2) I took out a bunch of crap from the front of the trailer.

New buyer was towing with a Toyota Tacoma. The first/easiest thing to do was to up the tire pressure in the rear of the Tacoma to max recommended pressure. Calls back one hour later to report that everything is great. A simple fix with positive results.

FWIW, I've always towed with the rear tires at their max recommended pressure in the tow vehicle. Has worked well for me over the years.

[JohnDeRosa]

I'll talk about a homebuilt trailer with leaf springs. Towed OK but I got pretty good sway when a semi passed, oddly most noticeably when it passed in the same directly.

After doing all of the assorted things mentioned above by others (which did help some) I ended up installing a sway bar kit which significantly corrected the situation. Your mileage may vary.

See http://www.etrailer.com/Weight-Distribution/Pro-Series/83660.html

- John

[[email protected]]

a friction stabilizer works wonders, and it is very common in Europe.
http://www.al-ko.com/322.htm

aldo cernezzi
www.voloavela.it

[Mark628CA]

Aldo is correct- a friction anti-sway device is very effective. There are a couple of things to consider, though.

The Al-KO clamping hitch is an excellent piece of gear, BUT WILL ONLY WORK WITH A 50 MM BALL! Normal 1 7/8 or 2 inch balls are too small or too large for the clamp to handle. I have installed a few of these on Cobra trailers and the results are excellent. Note that the ball MUST be welded or otherwise fixed to the receiver extension to keep the clamp from loosening the nut on the ball shank. I machine a "flat" on the base of the ball and weld a piece of bar stock to the hitch to keep things from moving.

This is a rather expensive solution, and the AL-KO hitch is not available in the US, so I bought some from a supplier in the UK. Note that this design is the only one I have seen that will work with the usual European surge brake coupler.

For a tongue without a surge brake, there are several designs that are inexpensive and very effective. Most will require some welding and proper alignment is necessary, so a pro should be consulted. Here is a link to sway control devices from etrailer.com: http://accessories.etrailer.com/search?w=sway%20control

Mark Mocho
MM Fabrication

[[email protected]]

I tow an Avionic behind a BMW 325 with a 2 inch ball- no problems.

[son_of_flubber]

On Thursday, June 12, 2014 9:34:18 AM UTC-4, wrote:
> I tow an Avionic behind a BMW 325 with a 2 inch ball- no problems.

Lots of good ideas shared here. Thanks.

My goal is to achieve 70 mph stable towing for East Coast towing and 80 mph for western states towing.

From comments made here, it appears to be possible to achieve these numbers with the Avionic torsion bar suspension with a moderate sized vehicle like Volvo XC70.

Things to try:

1)Increase tongue weight which is a measure of how much the CG is forward of the axle.

2)Increase cargo mass close to the tow ball in both the trailer and the tow vehicle.

3)Trailer tires- use trailer type tires, use max pressure to increase sidewall stiffness. Avionic specific, increase tire size to 175 from 165.

4)Tow vehicle- increase cargo mass near tow ball, verify/upgrade suspension stiffness, increase rear tire pressure for sidewall stiffness. Possibly upgrade rear tires for side movement stiffness.

5)Check that the axle is perpendicular with the longitudinal axis of the trailer. Correct misalignment if possible.

My glider is assembled in a hangar, so I'll experiment to get the best performance with the empty trailer and expect things to change a bit with the glider. I'll replicate the best tongue weight when I put the glider back in and go from there. The trailer CG is close to neutral with the glider and nothing else in the front of the trailer. One of the best trailer sales/maintenance meccas in the region is within an hour's drive of the airport and I will get their help if I still have problems.

[[email protected]]

On Thursday, June 12, 2014 11:24:57 AM UTC-4, son_of_flubber wrote:
> On Thursday, June 12, 2014 9:34:18 AM UTC-4, wrote:
>
> > I tow an Avionic behind a BMW 325 with a 2 inch ball- no problems.
>
>
>
> Lots of good ideas shared here. Thanks.
>
>
>
> My goal is to achieve 70 mph stable towing for East Coast towing and 80 mph for western states towing.
>
>
>
> From comments made here, it appears to be possible to achieve these numbers with the Avionic torsion bar suspension with a moderate sized vehicle like Volvo XC70.
>
>
>
> Things to try:
>
>
>
> 1)Increase tongue weight which is a measure of how much the CG is forward of the axle.
>
>
>
> 2)Increase cargo mass close to the tow ball in both the trailer and the tow vehicle.
>
>
>
> 3)Trailer tires- use trailer type tires, use max pressure to increase sidewall stiffness. Avionic specific, increase tire size to 175 from 165.
>
>
>
> 4)Tow vehicle- increase cargo mass near tow ball, verify/upgrade suspension stiffness, increase rear tire pressure for sidewall stiffness. Possibly upgrade rear tires for side movement stiffness.
>
>
>
> 5)Check that the axle is perpendicular with the longitudinal axis of the trailer. Correct misalignment if possible.
>
>
>
> My glider is assembled in a hangar, so I'll experiment to get the best performance with the empty trailer and expect things to change a bit with the glider. I'll replicate the best tongue weight when I put the glider back in and go from there. The trailer CG is close to neutral with the glider and nothing else in the front of the trailer. One of the best trailer sales/maintenance meccas in the region is within an hour's drive of the airport and I will get their help if I still have problems.

1- Any tongue weight over about 100 lb is doing no good and possibly bad.
2 Is not correct. You want the mass in the vehicle between the axles, not behind the rear axle as this only adds to the extra load the rear suspension sees.

You may want to tow the trailer with a known good tow car to see how much is the trailer and how much is the car.
UB

[Six-Seven]

On Thursday, June 12, 2014 7:39:03 AM UTC-5, Mark628CA wrote:

> For a tongue without a surge brake, there are several designs that are inexpensive and very effective. Most will require some welding and proper alignment is necessary, so a pro should be consulted. Here is a link to sway control devices from etrailer.com: http://accessories.etrailer.com/search?w=sway%20control

I did install this item without welding.

- Basically the only think that you need to do is mount two small 1-1/4" diameter balls that come with the kit.
- The first 1-1/4" ball goes a few inches left or right of the main trailer ball. This looks exactly like a miniature "standard" ball. The easiest way to mount this is via an accessory plate that goes underneath the main trailer ball. http://www.etrailer.com/Accessories-and-Parts/Reese/RP26003.html
- The second 1-1/4" ball is provided already welded to a plate which is intended to be bolted to the trailer tongue. I bought a second ball (like the first one) and put that into a drilled and tapped hole in the tongue. http://www.etrailer.com/Accessories-and-Parts/Curt/C40093.html
- The two 1-1/4" balls are mounted 24" apart and 90 degrees from one another.

[Bob Kuykendall]

On Thursday, June 12, 2014 8:24:57 AM UTC-7, son_of_flubber wrote:

> My goal is to achieve 70 mph stable towing for East Coast towing and 80 mph for western states towing...

I'd advise a modicum of caution in this matter. In many states, the maximum speed for towing any trailer is lower than the normal speed limit.

Getting popped for towing a trailer above the applicable speed limit can be a pretty strong ticket in many states. The patrol officer will not care that your trailer is really light and tows like it isn't there. The presumption will be that the trailer substantially reduces maneuverability and increases braking distance (both technically true), and you are unlikely to make much headway convincing either the officer or the judge otherwise.

Thanks, Bob K.

[Karl Striedieck[_2_]]

On Friday, June 6, 2014 6:44:32 PM UTC-4, son_of_flubber wrote:
> My Avionic trailer has leaf springs and no shocks and the rhythmic ass end sway that develops at higher speeds encourages me to keep the top speed at 60-65 mph. That speed is just fine with me except when interstate traffic if flying by at 80 mph. In that case I feel that I'm something of a hazard, especially if I'm trying to merge or change lanes.
>
>
>
> I'm thinking that shocks might dampen out the rhythmic sway that seems to be self-reinforcing. Tow vehicle is 2004 Volvo XC70. Single seat glass glider.

2nd try. The most important factor affecting trailer stability is the distance of the tow ball to the rear axle with zero being the theoretical optimum. Wil Schumann modified this 1966 Olds Tornado just that way.

So if there is a choice of vehicles go with the least "overhang." A VW Touareg is good, an extended van or pickup not so good. And the ratio of tow vehicle to trailer weight is important too. Heavier vehicle is better, as in RV's (which aren't affected by the relatively light trailer.

[Mike the Strike]

No restriction on trailer towing speeds here out in Arizona and I believe most adjacent states are similar. Posted limits are generally 75 mph (except Utah and Texas which have some higher ones) and most of these states will give you 10 mph grace.

For those going to Region 9 in Moriarty, I can confirm that speeding fines in New Mexico are very affordable (I got $75 for a trailer-free 92 mph).

Mike

[[email protected]]

California is 55mph with a trailer.

[son_of_flubber]

Trailer towing speed limits by state:

http://drivinglaws.aaa.com/laws/trailer-speed-limits/

I was woefully ignorant of this law and I'd guess that others are too.

Inadvertantly omitted from my previously posted list of possible remedies would be the possibility of adding shocks to Avionic trailers that have torsion bar and leaf spring suspension.

[Frank Whiteley]

On Thursday, June 12, 2014 3:30:00 PM UTC-6, Bob Kuykendall wrote:
> On Thursday, June 12, 2014 8:24:57 AM UTC-7, son_of_flubber wrote:
>
>
>
> > My goal is to achieve 70 mph stable towing for East Coast towing and 80 mph for western states towing...
>
>
>
> I'd advise a modicum of caution in this matter. In many states, the maximum speed for towing any trailer is lower than the normal speed limit.
>
>
>
> Getting popped for towing a trailer above the applicable speed limit can be a pretty strong ticket in many states. The patrol officer will not care that your trailer is really light and tows like it isn't there. The presumption will be that the trailer substantially reduces maneuverability and increases braking distance (both technically true), and you are unlikely to make much headway convincing either the officer or the judge otherwise.
>
>
>
> Thanks, Bob K.

Especially Illinois.

Frank Whiteley

[Frank Whiteley]

On Thursday, June 12, 2014 9:24:57 AM UTC-6, son_of_flubber wrote:
> On Thursday, June 12, 2014 9:34:18 AM UTC-4, wrote:
>
> > I tow an Avionic behind a BMW 325 with a 2 inch ball- no problems.
>
>
>
> Lots of good ideas shared here. Thanks.
>
>
>
> My goal is to achieve 70 mph stable towing for East Coast towing and 80 mph for western states towing.
>
>
>
> From comments made here, it appears to be possible to achieve these numbers with the Avionic torsion bar suspension with a moderate sized vehicle like Volvo XC70.
>
>
>
> Things to try:
>
>
>
> 1)Increase tongue weight which is a measure of how much the CG is forward of the axle.
>
>
>
> 2)Increase cargo mass close to the tow ball in both the trailer and the tow vehicle.
>
>
>
> 3)Trailer tires- use trailer type tires, use max pressure to increase sidewall stiffness. Avionic specific, increase tire size to 175 from 165.
>
>
>
> 4)Tow vehicle- increase cargo mass near tow ball, verify/upgrade suspension stiffness, increase rear tire pressure for sidewall stiffness. Possibly upgrade rear tires for side movement stiffness.
>
>
>
> 5)Check that the axle is perpendicular with the longitudinal axis of the trailer. Correct misalignment if possible.
>
>
>
> My glider is assembled in a hangar, so I'll experiment to get the best performance with the empty trailer and expect things to change a bit with the glider. I'll replicate the best tongue weight when I put the glider back in and go from there. The trailer CG is close to neutral with the glider and nothing else in the front of the trailer. One of the best trailer sales/maintenance meccas in the region is within an hour's drive of the airport and I will get their help if I still have problems.

You're coming out west? Mountain passes in Colorado top 10,000 MSL. Snow recently on Berthoud pass for the Ride the Rockies Bicycle Tour. Wyoming and New Mexico not so bad. Montana's okay also. Arizona, Flagstaff to Tucson is interesting, both ways. Bring range, horsepower, and all or 4WD. Nevada and California are okay. Idaho, Washington, and Oregon are mostly easy. The Pendleton grade is fun, both ways, and interesting on ice. I'm presuming summer travel. Winter is a bit different when I'd recommend a big tow vehicle option.

Frank Whiteley

[son_of_flubber]

On Friday, June 13, 2014 12:23:47 AM UTC-4, Frank Whiteley wrote:

> You're coming out west? Mountain passes in Colorado top 10,000 MSL. Snow recently on Berthoud pass for the Ride the Rockies Bicycle Tour. Wyoming and New Mexico not so bad. Montana's okay also. Arizona, Flagstaff to Tucson is interesting, both ways. Bring range, horsepower, and all or 4WD. Nevada and California are okay. Idaho, Washington, and Oregon are mostly easy. The Pendleton grade is fun, both ways, and interesting on ice. I'm presuming summer travel. Winter is a bit different when I'd recommend a big tow vehicle option.

> Frank Whiteley

The earliest that I would tow my glider out west would be 2016. Getting ready now to tow from Vermont to Florida in Nov 2014 and back to Vermont in 2015.

>Bring range, horsepower, and all or 4WD.

My 2004 Volvo XC70 has all of that, highish ground clearance, comfortable seats and a 'safety cockpit'. It is a light truck trapped in a station wagon body (with a low CG compared to most light trucks/SUVs). That said, a two-wheel drive full size van tempts me.

[[email protected]]

On Friday, June 13, 2014 8:57:25 AM UTC-6, son_of_flubber wrote:
That said, a two-wheel drive full size van tempts me.

Like this one?

http://gallery2.jpmullan.com/v/scans/cars/myvan.jpg.html

[2G]

On Friday, June 13, 2014 7:57:25 AM UTC-7, son_of_flubber wrote:
> On Friday, June 13, 2014 12:23:47 AM UTC-4, Frank Whiteley wrote:
>
>
>
> > You're coming out west? Mountain passes in Colorado top 10,000 MSL. Snow recently on Berthoud pass for the Ride the Rockies Bicycle Tour. Wyoming and New Mexico not so bad. Montana's okay also. Arizona, Flagstaff to Tucson is interesting, both ways. Bring range, horsepower, and all or 4WD. Nevada and California are okay. Idaho, Washington, and Oregon are mostly easy. The Pendleton grade is fun, both ways, and interesting on ice. I'm presuming summer travel. Winter is a bit different when I'd recommend a big tow vehicle option.


>
>
>
> > Frank Whiteley
>
>
>
> The earliest that I would tow my glider out west would be 2016. Getting ready now to tow from Vermont to Florida in Nov 2014 and back to Vermont in 2015.
>
>
>
> >Bring range, horsepower, and all or 4WD.
>
>
>
> My 2004 Volvo XC70 has all of that, highish ground clearance, comfortable seats and a 'safety cockpit'. It is a light truck trapped in a station wagon body (with a low CG compared to most light trucks/SUVs). That said, a two-wheel drive full size van tempts me.

You never said what kind of tires you have on the trailer. Use ONLY trailer rated tires (they have stiffer sidewalls than car tires). As recommended previously, check alignment by measuring the distance from the ball to both wheel axles. Look at tire wear for signs of misalignment (uneven wear, scallops). Replace the tires if more than 4 years old. Believe me, a tire blowout at 75 mph is no fun and will likely cost you an extra day. Make sure you have a good spare, btw. Anti-sway friction devices are a bandaid and should be used only as a last resort (and reduce your speed: trailer towing upsets can, and have been, fatal). Measure (don't guess) your tongue weight. It should be a MINIMUM of 5% of the trailer weight, and closer to 10% (that will be 150 to 200 lbs!). You may have to add air shocks to your tow vehicle to support this weight (which is easy to do).

Your vehicle should be able to tow your trailer at all legal highway speeds, so something else is wrong.

Tom

[GC[_2_]]

On 14-Jun-14 00:57, son_of_flubber wrote:
> On Friday, June 13, 2014 12:23:47 AM UTC-4, Frank Whiteley wrote:
....
>> Bring range, horsepower, and all or 4WD.
>
> My 2004 Volvo XC70 has all of that, highish ground clearance,
> comfortable seats and a 'safety cockpit'.

No, it doesn't. Karl gave the 2 main rules and the XC70 doesn't follow
either.

> It is a light truck
> trapped in a station wagon body (with a low CG compared to most light
> trucks/SUVs).

1. I haven't measured it but my eye tells me that there is too big a
distance from the towball to the axle - because of its station wagon
heritage.

2. It's too light. TINSFOM - there is no substitute for mass. My 4WD
is 2.2 tonnes and doesn't take crap from glider trailers.

GC

[Bill D]

On Sunday, June 15, 2014 8:01:30 AM UTC-6, GC wrote:
> On 14-Jun-14 00:57, son_of_flubber wrote:
>
> > On Friday, June 13, 2014 12:23:47 AM UTC-4, Frank Whiteley wrote:
>
> ...
>
> >> Bring range, horsepower, and all or 4WD.
>
> >
>
> > My 2004 Volvo XC70 has all of that, highish ground clearance,
>
> > comfortable seats and a 'safety cockpit'.
>
>
>
> No, it doesn't. Karl gave the 2 main rules and the XC70 doesn't follow
>
> either.
>
>
>
> > It is a light truck
>
> > trapped in a station wagon body (with a low CG compared to most light
>
> > trucks/SUVs).
>
>
>
> 1. I haven't measured it but my eye tells me that there is too big a
>
> distance from the towball to the axle - because of its station wagon
>
> heritage.
>
>
>
> 2. It's too light. TINSFOM - there is no substitute for mass. My 4WD
>
> is 2.2 tonnes and doesn't take crap from glider trailers.
>
>
>
> GC

There is a test for tow vehicle suitability. Just push the rear of the tow vehicle sideways with your hands in a rhythmic manner until you find its natural resonant frequency. My old Jeep Grand Cherokee's resonant sway exactly matched my Komet trailer's - no wonder the rig would weave all over the highway above 65MPH.

My theory is every tow vehicle/trailer rig is dynamically unstable above some speed. All one can hope to do is try to raise that speed high enough it isn't a practical limitation - then never exceed that speed.

[Mike the Strike]

....and if you live somewhere warm don't buy cheap Chinese trailer tires - they are made from a low melting point mystery plastic!

Mike

[Eric Greenwell[_4_]]

Mike the Strike wrote, On 6/11/2014 6:17 AM:
> My 2001 Cobra trailer arrived from the previous owner with lead
> weights and dumbbells at the front to increase tongue weight. I
> removed them and found still plenty of tongue weight and no towing
> instability behind a Toyota 4Runner at speeds up to 85 mph (Arizona
> highway speed!) I replaced the tires last year with recommended
> trailer tires and have absolutely no problems except in very strong
> gusty side-winds, when I slow to 70 mph.

Gulp! _Slow_ to 70 mph? Better check the speed rating on those ST
trailer tires, because the standard rating is only 65 mph! Some ST tires
are rated up to 75 mph, using different load inflation charts (generally
requiring much higher inflation pressures) than the normal ST tires.
Those stiffer sidewalls people like to talk about are intended for
stability, and the tradeoff is they heat up more easily.

Most people don't realize how different ST (trailer tires) from other
tires. They are not "stronger" passenger car tires, or even "stiffer"
light truck tires. They are designed for a specific purpose that is
quite different than car and truck tires.

If you want to tow your trailer at 85 mph, you better get LT (light
truck) tires with the appropriate speed rating (I'd use a speed rating
of at least 100-110 mph), and be sure you have them at the correct pressure.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorgliders/publications/download-the-guide-1
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl