trailering

Pete:

If I have to strain I move the boat back. I think you want about 100-150 lbs, but I am not sure? Need a expert here.

Doug

The general rule of thumb is to have 10% of the load weight on the tongue. Just use a bathroom scale to weigh what you have. If you do not already know the weight of the boat, trailer, and box with gear, then you can take it to a truck scale (many local businesses) for an accurate total weight - usually for just a few bucks. Easy way to adjust the tongue weight is by boat placement but it could mean moving the trailer axle if it is way off or the boat position is set.

Don't move the axle too far forward or the frame behind the axle will slooooowwwwwwly sag.

I think it is better to err on the side of too much tongue weight rather than too little. I was trailering two double-stacked boats to Ohio last year, and after having driven a couple hundred miles with no problem, suddenly the trailer started fishtailing badly. I was on a freeway, and I had to keep slowing down to about 40 mph to get the fishtailing under control each time it started.

So I stopped early for the night and I asked the advice of a trucker who was staying at the same motel. He checked out the trailer and said the axle is bowed down and the wheels are canted out and the bearings on the starboard side are probably going to disintegrate soon from the stress. He advised me not to drive far. I said, "Well, I have to go another 700 miles." He said, "No way. Go to a repair place and get a new axle and replace the bearings."

I did not take his advice. Instead, I decided that the boats had slid back on the trailer because of not being tied tight enough. (Not our boats and not our trailer.) Figuring the problem might be from not enough tongue weight, I pushed the boats forward a little, tied them down very tight, and had no problem the rest of the way to Ohio.

The 10% rule is a good one. In teh case of most of our cats that is about 100-150 lbs of tounge wight. I know that class 1 hitches are rated for 200 lbs max tounge weight. Here is why balancing a trailer is so important:

1) If the weight is too far forward you will have too much tounge weight (obviously). This will cause the back end of your vehicle to lift the weight off the front wheels resutling in less ability to steer effectively on slippery road surfaces (or clean one depending on how bad it is). This is mostly dependant on your tow vehicle.

2) If the weight is too far aft (too little tounge weight) then the vehicle is "holding" the trailer down and the trailer wants to whip (like in Mary's case) which will toss the back end of your vehicle around and wear out the trailers suspension and bearings as well as your vehicles.

So, you want to lod the trailer such that the tounge weight does not depress the rear suspension of your tow vehicle too much, but just enough. I know this is not exact, but you can feel the difference between a properly balanced trailer and on that is not. Very tow vehicle dependant.

For example. On my VW Passat 1.8T (yes a 150 HP 4 cyl), manual. I tow the TheMightyHobie18 on a Trailex trailer. I line up the front cross bars of the boat and trailer. I usually have the mast top out as far as the rudder tips are when locked up. This gives me about 125 lbs of tounge weight and great balance. The car steers very well in all conditions.

Fishtailing is caused by the center of gravity not being forward of the axle.
tongue weight should be enough to make sure you do not fishtail, and be less than the limit of the hitch.
my old hitch had a 200# limit, and that is very uncomfortable to lift, so I use what is comfortable to lift at the hitch end, 75 to 100#.

All good info in here. A couple of points though.

Actually you are supposed to have 8% of the total trailer weight on the tounge of the trailer.

Also the weight is not nessessarily the same as the weight on the front wheel. Sometimes those trailer wheels can be set back from the tounge a good distance which would be different from the tounge weight.

So if your trailer weighs 1000lbs you need 80lbs on the actual tounge of the trailer.

Mike Hill

Thanks Mike for clarifying the 8%. I don't know what your source is but it makes common sense to me. I'm not the biggest or strongest guy around but I've pulled many different trailer/boat combo's with less than 100 lbs. of tongue weight and never had a problem (not double stacked mind you) and it's easier on my back. I've always adjusted the boat forward or back on the trailer to get a managable weight to lift.

All great info! Now, how FAST do people feel comfortable towing a cat?

I would say under 70. 60 might be better.

Hi guys,

I do around 35,000 miles per year and 90% of that is either towing around 3-4000 lbs for work or 2 f18's & associated stuff.

IMHO the 8-10% theory is ok up to 150lbs. Most car tow hitches are designed to have max 200lbs vertical load and up to 5000lbs gross trailer weight.

As for speed - if your trailer is loaded properly and the load tied down, speed is generally not an issue. (Have been guilty of making a TheMightyHobie18 do 120mph down a fwy late for a regatta many years ago . Common sense needs to apply though - you can't go around corners anywhere near as fast and stopping distances are longer.

Tiger Mike

Speed is also dependant on the tire diameter and how much you trust your bearings. The larger the tire the faster you can go since the bearing angular speed is reduced.

Again, drive so you can control your car and the trailer. Keep your distance from vehicles in front of you since you can't stop as fast (especially the smaller lighter vehicles that seem to stop on a dime).

I have found with my trailer and car I feel comfortable going about 70-75 mph on the interstates. When the wind is blowing I slow down since the trailer is relatively light and gets blown around.

Make sure everything is secured very well. I was coming back from a week long vacation in Vermont 2 years ago and was drivng behind my freind who was pulling his TheMightyHobie18. The front tie-downs failed and the bows lifted straight up in the air. While it was vertical it rotated around the rear tie down, landed on the pavement and was drug sterns first for about 500 ft until he could pull it off the road.

This all happened about 5 car lengths in front of me. Had the rear tie down not held it would have been a very painful (or very short) expereince for me. Fortunatly the only damage was to his keels and it was repaired.

It never hurts to have an extra tie down in place.

I pulled a Bobie 20 to Florida and back twice. I average about 70 when I have a clear road. Eileen does about 80...rock on girl! We pull it with a Mustang 5 liter (302). Knock on wood, no problems.

Dan

Interesting info. The situations that scare me the most while trailering (I keep it to 60-65, after that my gas milage goes WAAAAAY down), is being passed by big rigs. The amount of air those thing push around is astounding and cause the trailer to weave all over. Any advise to keep the trailer in shape when being passed by these behemouths?

When towing a lightweight setup like a cat, there is not much you can do. Just anticipate the surge and try to keep from getting blown off the road. Heavy trailers and boats move much less. For example my Stiletto 27 doesn't move when a rig passes by, I actually like the push to keep that thing moving . It probably about 2500#, boat, trailer and gear.

Nope they don't make beach wheels for that one!

Clayton

Which works better for trailer stability: having a wide axle with the wheels far apart or having a narrow axle with the wheels close together? And whichever way is better, WHY?

Mary, I think we can apply the same principle from sports cars with excellent road gripping abilities. The wider the wheelbase, the better.

I do beleive is the wheel base is wider, the center of gravitiy is stationed towards the center and barely shifts. If the wheel base is narrow the center of gravity is more substantial to shifts, left right for and aft.

Also another thing that works good with trailors is to have bigger wheels/tires. Bigger wheels and tires will lessen the rotation on the bearings. Making them rotate less, causing less wear and tear through reduced heat.

Mary,

When you say stability what, exactly, do you mean? It is resistance to tipping over sideways? If yes, then a wider stance in better, i.e. a cat vs a mono.

Or do you mean how much the trailer "dances" around behind the tow vehicle? If yes, then a longer distance from the trailer hitch to the axel will have a much greater affect than a wider stance. That distance being longer will cause the trailer to follow your tow vehicle better (it will center it self better) and it will make backing up much easier.

By "stability" I meant how well it tracks behind the towing vehicle and how little it gets thrown around when big vehicles pass it.

So you are saying that this is not necessarily specifically related to the width of the axle, but is also related to the length of the trailer tongue?

I'm not an engineer, so bear with me on this. If you have a narrow axle and your trailer wheels are close together, does that mean you should have a shorter tongue. And if you have a wide axle (wheels far apart), you need a longer tongue? Or is it vice versa?

I know I have followed some trailers with very wide axles, carrying ATV's, and they seem to be all over the place. And I have followed one of our trailers with the narrow axle carrying three boats, and it seems to track very true.

So is this all a function of relative tongue length vis-a-vis axle width? (Assuming proper weight on the hitch.)

so basically you didn´t mind risking other peoples boats, trailer and perhaps other peoples lives on the highway..

Exactly. However, you do need width to add stability if your load is higher to keep it from tipping over.

Andinista,
Well, it was all in the family. My sister and her husband had bought them, and I was bringing them up to Ohio to help form our new Wave fleet. They had bought them from another friend of ours down here in Florida who had been sailing Waves with us and who is impeccable about maintaining his boats and his equipment and had been trailering his boats all over Florida with this same trailer with no problems whatsoever.

The only problem was that he does not hogtie things down as much as I do, and the boats had slid back a little bit. No big deal. It was just common sense to redistribute the load, and I'm sorry I even consulted that so-called trucker.

As far as risking the lives of other people on the highway, I don't think so. Based upon his analysis, the worst thing that could have happened was that the bearings might go on one of the trailer wheel hubs, which would have left me possibly stranded alongside the road for a while.

Have you ever heard a high singing noise when you are pulling a trailer? That's the sound of wheel bearings starting to seize up. Rick and I have experienced that twice, and both times we have ended up staying overnight in unplanned places.

Doesn't endanger others, but it's not something I wanted to experience all by myself pulling a trailer through the mountains.

Fortunately, shifting the load forward and tying it down better solved the problem. Although, I still worried about the bearings all the way north.

Ok. The sentence "Instead, I decided that the boats had .." sound like the theory came out just as an easier alternative than hearing the guy's advice.

Hey, I heard the advice, and I passed it on to my sister, the new owner of the boats and trailer, in case they ever want to take it anywhere off the island, which is unlikely.

Now, the interesting thing about all this is that the wheels on that particular trailer were very far apart, wide axle. It was always carrying two Waves double-stacked. And, as I mentioned, the axle was bent (bowed down a little bit), which caused the wheels to cant outwards a little bit, which caused more pressure on the wheel bearings.

SO, I am just wondering whether there is also some engineering ratio to determine where the wheels should be under the load so that it will not stress the axle. Is more in better than more out?

The tracking of the trailer has very little (if anything) to do with the stance of the wheels. It is the longer tounge that will keep it tracking behind the two vehicle. It will still blow around when a semi passes you, or you the semi, but it will not jerk the tow vehicle around as much and will recenter in a much more gentle way than a short tounged trailer will.

It's like the wheel base on a car. If you ride in an old CJ5 Jeep dow the highway, every little bump in the road will rock the jeep. If you ride in a road boat station wagon with the really long wheel base, you don't feel the bumps as much. (For those of you who will jump on me and point out suspension differences, assume they are using the same suspension).

For a more nautical reference imagine sailin a small 8' dinghy in 1' seas. Then imagine sailing a 16' dinghy in the same seas. Much smoother. Rotate the plane of motion 90 deg and you have your trailer. Instead of your contact points being the bow and stern causing pitch they are the hitch and wheels causing yaw.

I hope this cleared things up and didn't make it more complicated.

You needed a beefier axel. It sounds as if it was overloaded. Most small boat trailers are good for about 600 - 1000 lbs. The only way to remove the torsion you saw on the wheel bearings is to apply your load to both sides of the wheel.

I'm pulling this out of a vehicle stability class that I took while studding Mechanical Engineering in college. It's been a few years so if I'm mistaken feel free to correct me.

From what I remember, there are three areas of stability:

Stable, under normal speeds when disturbed the trailer will always follow behind the towing vehicle and any oscillations (bumps in the road) will dissipate.

Critically stable, the vehicle will remain stable under a threshold speed and any oscillations will dissipate. Over this speed the oscillations will increase until you loose control of the vehicle (fishtail).

Unstable, at any speed any oscillations will increase and you will loose control at even the smallest speed.

Warning, if you’re not an engineering nerd you may want to skip this next paragraph:

Stability has to do with where your eigen values are located when plotted on a real vs imaginary graph. For fundamental stability the eigen value must be in the quadrent located above the real axis (x axis) and to the left of the imaginary (y axis). Critical stability occurs when any eigen value is located on the y axis and above the x axis, and fundamental unstability occurs when the eigen value is located to the right of the y axis.

When it comes to trailers this is a direct function of where the center of mass is in relation to the axel of your trailer.

If your center of mass is in front of the axel the trailer will remain stable.

If the center of mass is right at the axel, your trailer will be critically stable, over the threshold velocity it will oscillate out of control. This type of loading should be avoided because there is really no easy way to know what the threshold velocity is. Unless you like finding out the hard way.

The trailer will be unstable if the center of mass is behind the axel. This is unsafe at any speed.

I remember a demonstration we had in class where we had a bicycle with a trailer which had a 2 lb weight in it. Just putting this little amount of weight behind the axel was enough to throw someone off the bike at a walking pace.

It's super easy to know what kind of loading you have. If the tongue of the trailer is on the ground before you hitch up and take off you'll be fine, just make sure the load can’t shift. If the tongue is balanced evenly or up in the air, you're screwed.

Of course the easiest way to make a trailer unstable is to simply put your car in reverse.

I’ll put my pocket protector away now.

Adam

Before you put your Mech. Eng. texts and SAE handbooks away, please re-assure the folks that 8" wheels are just fine (for single cat trailers, anyway), and will not "overheat" the bearings at speeds under 100mph. Wheel bearings must meet minimum DOT/SAE/etc. standards, which generally have LOTS of margin built-in. What makes bearings overheat is EXTREME OVERLOADING (or overtightening during installation) and (*ta-DAH*) INSUFFICIENT LUBRICATION, period. Spring loaded hubs, which maintain positive grease pressure, i.e. no air voids, thereby keeping water out, go far in this regard. So does periodic maintenance.

I've had trailers with both size wheels, and in retrospect, I like the 8" better because the boat was lower to the ground, ergo easier to launch, recover, and hop up on to step the mast.

I too worried about the THEORETICAL overspeed of the bearings with my 8" wheels, so once after driving 120 miles non-stop at 70MPH, I pulled over to the shoulder, hopped right out and felt both hubs in quick succession... air temperature. NO problemo...

Of course all of the above applies only to bearings made in the G8 industrial countries. If you buy bearings made in Red China, well, I hope you enjoy the $2.86 savings while your $20,000 A-cat gets a terminal case of road rash.

\

One other factor is how much fuel is in the towing vehicle’s tank. Fuel weighs 5.8 to 6.5 lbs. Ethanol is 6.59 lbs. Diesel is 7.0 to 7.3 lbs. If a vehicle has a 20 gallon tank you mat see stability change as the fuel is used.

When I was in the Army, I had a signal group with a bunch of M151A1 Jeeps (pre Hummer) equipped with trailers. None of the guys in the section had ever pulled a trailer before. After I finished with them they were doing figure-eight races in reverse around two warehouses. The major I worked for freaked out until I got him into a Jeep. He turned out to be a pretty good competitor.