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

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.

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.

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

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

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/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Feb/2010" also ADS-B, PCAS, Flarm
http://tinyurl.com/yb3xywl

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.

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-Distr...ies/83660.html

- John

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

aldo cernezzi
www.voloavela.it

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

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-...e/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-...rt/C40093.html
- The two 1-1/4" balls are mounted 24" apart and 90 degrees from one another.