tongue weight

[WaterWitch2]

Which is worse? Too much tongue weight or too little tongue weight? I have a 1978 Glastron 176 SSV with 1978 140 Johnson on a single axle trailer (boat in my Avatar). I have dual batteries and empty fuel tank. I don't know total weight yet but 255 lbs on the tongue seems heavy.

 

[tashasdaddy]

Re: tongue weight

according to NADA boats, you hull dry weight out of the factory was 950lbs, motor 325 lbs, guessing trailer at 600lbs. gear, full tank of fuel, 300 lbs. total 2175 lbs. tongue weight should be around 200 lbs. if possible, and if you have to replace the bunks and moved the boat back on the trailer about 5-6 inches. then try the weight. also the trailer should be level when on level ground, get a drop reciever to get the height of the tongue correct.

 

[WaterWitch2]

Re: tongue weight

The transom is about 4" from the back edge of the bunks but I need to replace them any way so I'll just lenghten them. The winch post has a lot of adjustment so no problem. The trailer isn't the original for the boat. Getting ready for maiden voyage in a couple of weeks. This is about the last thing to do. What is the easiest way to move boat back? Tie transom eyes to something and pull trailer forward with truck?

 

[Expidia]

Re: tongue weight

I just did this tonight to my boat as I had to move the axle back one mounting hole.

The easiest way (and the safest) is to take it to your nearest launch area and just float the boat off the trailer. Then crank it up but leave it a little longer than you want it over the bunks. I pulled out of the launch with about 3 feet of winch strap between the winch and the boat.

Pull up away from the launch area. Re-position the winch and crank the boat to an inch or two of bunk showing below the transom.

The wet bunks are easy to crank the boat into the exact position you need it.

Nice part of this is if you don't like where the boat is after you are done just back it down the launch again and do it again.

I pondered jacking the boat up and trying this in my driveway at first but changed my mind when I pictured the boat crashing down or worse falling on me!

Trailered it home with the new axle position and double the old the tongue weight. It's much better now without the boat banging around as before. Car also used to jerk back and forth before on the side roads, which can't be good for my tranny.

Dealer was going to do it for me, but I did not want to lose the boat for more days. Re-positioning the trailer wheels only involved removing and replacing 4 bolts and nuts.

 

[tashasdaddy]

Re: tongue weight

ecpidia, you did it right for your trailer, but his axle is not movable, he has to repostition the boat.

 

[Expidia]

Re: tongue weight

expidia, you did it right for your trailer, but his axle is not movable, he has to reposition the boat.

Ya, I saw that. I was just first commenting on the floating of the boat off the trailer to easily re-position the boat back on a trailer.

I was explaining what I just went through so when others do a search for similar problems they will see the best way if you can, is move the axle like I did.

BTW I'm getting good at this since two days ago I had moved the axle forward an extra hole. I went into the dealer before I did it and asked him "now, these are the 4 bolts I need to remove and I also asked him . . . I need to move the axle forward towards the car RIGHT? He said yes, that's right".

This is why I had to drive all the way back to the launch and do the whole process over and move the AXLE BACK this time which increased the tongue weight to about 12%.

 

[dogbone]

Re: tongue weight

Here is a good site that may help you, I would just move your winch tower back about 3 inches and you probably don't have to lengthen your bunks if you are only 4 inches in now another 3 inches won't hurt http://www.loadrite.com/Support/Maintaining_Your_Trailer/Trailer_Adjustment_Boat_Trailers/76/

 

[WaterWitch2]

Re: tongue weight

ecpidia, you did it right for your trailer, but his axle is not movable, he has to repostition the boat.

My axle is movable (with holes every 6") but I would rather move the boat on the trailer. I think it would look stupid with the axle that far forward.

 

[WaterWitch2]

Re: tongue weight

Thanks everyone. I moved boat back 3" on the trailer and now have about 178 lbs for tongue weight and the bunks still stick out past transom about 1". Boat=950 lbs, trailer (same as my old trailer) 500 lbs, motor 300 lbs (unfortunately no power trim), batteries 90 lbs, fuel 75 lbs (2 6 gal tanks), misc gear 85 lbs (other misc gear in truck bed) = 2000 lbs. Tongue weight = about 9% instead of almost 13%.

 

[jeeperman]

Re: tongue weight

It is worse to have too little tongue weight.
It matters not if your running 5% or 30% of the trailer weight.

The proper amount is the amount it takes to keep the trailer from swaying at highway speeds.

 

[Silvertip]

Re: tongue weight

I disagree with you Jeeperman. Tongue weight is key factor in safe trailer towing and neither 5% or 30% fall anywhere near acceptable limits for a dead weight hitch. While some trailer manufacturers recommend 7% as ideal, it is generally accepted that 10% to 15% of trailer weight is acceptable. If you take a peek at the trailering section on the GM web site you will find they recommend those numbers as well. If you had 30% tongue weight on a 3000# trailer you have 900# on the hitch which is way over what most dead weight hitches (and the suspension) can handle. On the other hand, 5% of 3000# is way under the acceptable limit and would likely cause sway issues.

 

[Mike722]

Re: tongue weight

Too little tongue weight can also cause a danger in unhooking or storing a boat off the vechicle. Tongue may come up all of a sudden.

 

[Matthew_B]

Re: tongue weight

Acceptable tongue wight varies greatly depending on the type of boat. In general boats trailer far better than box type trailers because the axle(s) are farther back. With the axle farther back, the tow vehicle has more control over the trailer because the tongue to axle lever arm is longer, giving more leverage.

The 10% to 15% number is for box shaped trailers like travel or cargo trailers. They have a center of gravity and axle location far more forward of a boat.

Center engined boats are going to be close to the 10% requirement. I/Os only need around 7% to be stable. A outboard boat only needs 5% because the weight is so far rearward.

 

[Silvertip]

Re: tongue weight

Once again, I need to disagree. Trailers are made the way they are because of the balance of the load they carry which in the end allows adjusting tongue weight within certain limits. If you ever towed a large travel trailer you will know that the "long lever" you mentioned is a disadvantage when being passed by a semi. The air wave off the front of the truck hits the back of the trailer first tending to push it to the right. The tongue therefore moves left and hence takes the tail end of the tow vehicle with it which points the nose of the tow vehicle toward the ditch. Too little tonuge weight in that or any other trailering scenario results in the same condition and can in an extreme case, unload the rear end of the tow vehicle enough to cause loss of control. I really feel many of the Ford Explorer trailer towing accidents were caused by that problem and therefore much of the blame on the Explorer was unfounded. Load a box type trailer incorrectly and you have the same effect as loading a boat trailer incorrectly. Tongue weight is tongue weight. 5% is too little, anything over 15 - 20% is too much. It doesn't matter what type of trailer you have or what you a hauling. It needs to be load balanced properly and that's done with tongue weight. As was pointed out earlier, 5% tongue weight can get you under the chin should you disconnect the trailer when you've forgotten to take that heavy stuff out of the back of the boat, or you get into the boat behind the axle, or the boat is parked downhill and you have a bilge full of water. I have seen a guy go down the hill in his boat at his house when he did just that. No damage but a heck of a ride and fortunately no cars or kids were in the way. Another reason to use wheel chocks.

 

[Matthew_B]

Re: tongue weight

If you ever towed a large travel trailer you will know that the "long lever" you mentioned is a disadvantage when being passed by a semi. The air wave off the front of the truck hits the back of the trailer first tending to push it to the right. The tongue therefore moves left and hence takes the tail end of the tow vehicle with it which points the nose of the tow vehicle toward the ditch.

You need to compare the lever arm in front of the axle to the lever arm behind the axle. That's exactly the problem in trailers that are shaped like a giant brick. At 10% tongue weight, there is 3/5 of the box in front of the axle and 2/5 behind. That lever arm behind the axle gives the back of the trailer a lot of control over where the whole thing goes as you note.

I note that you use the example of a travel trailer, not a boat. Because boats are just plain far more stable than any travel trailer.

Compare that to a I/O or outboard boat. At 10% tongue weight, the axle is closer to 9/10 of the way back. Nothing is back there catching air to make it unstable. Rear engine power boats simply don't need 10% to be stable.

Tongue weight is tongue weight. 5% is too little

Then how do you explain open top aluminum boats with outboards? 30% to 40% of the weight of the boat is in the engine, behind the transom. They typically have the axle within a foot of the transom, practically at the rear end of the trailer. Even then, the tongue weight is under 5%, often around 3 or 4%. And they are dang stable, narry a wiggle when passed by a semi - even with a 20' boat. No worry about the tongue going negative weight, because unless you hang something from the engine, you can't shift the weight back.

I have seen a guy go down the hill in his boat at his house when he did just that. No damage but a heck of a ride and fortunately no cars or kids were in the way. Another reason to use wheel chocks.

Regardless of tongue weight, chocks are needed. The tongue jack wasn't designed as a parking brake. Those that don't chock will eventually find a steep enough hill that the trailer will run away on it's own.

 

[Silvertip]

Re: tongue weight

Matt -- Nobody is holding a gun to your head to force you to run light tongue loads. 5% on any trailer (boat, box, cargo, or whatever) is not enough tongue weight and 3 - 4% is worse -- that's my veiw and I'm stickin' to it. Axles are placed where they are because of the load the trailer is designed to carry. Of course trailers for outboards are designed with the axle close to the rear. You couldn't get the required tongue weight if it was moved forward. Box trailer manufacturers have no idea what is going in that trailer so they center or slight offset the axle to the rear. It is up to the owner/loader to properly pack the trailer. Tandem, tri, and four axle trailers will naturally track straight so a lighter tongue load can be tolerated with a very big HOWEVER, it depends on the tow vehicle how that load reacts in a sudden evasive manuever. I have a number of trailers -- the smallest being a 4 x 6 utility. Load it with a light tongue and its sways like crazy. I saw a dude spread a load of pea gravel all of the interstate one day due to a light tongue load. Sway set in, the driver had trouble controlling that sway, and he lost total control as the trailer whipped sideways spilling the load as the tail gate came loose. 7% to 15% is the recommended tongue weight and 10 -15% is more accepted. Those are the numbers I've adhered to for more years than you are old (that's a guess by the way) and have always had perfectly towing trailers.

 

[jeeperman]

Re: tongue weight

I disagree with you Jeeperman. Tongue weight is key factor in safe trailer towing and neither 5% or 30% fall anywhere near acceptable limits for a dead weight hitch. While some trailer manufacturers recommend 7% as ideal, it is generally accepted that 10% to 15% of trailer weight is acceptable. If you take a peek at the trailering section on the GM web site you will find they recommend those numbers as well. If you had 30% tongue weight on a 3000# trailer you have 900# on the hitch which is way over what most dead weight hitches (and the suspension) can handle. On the other hand, 5% of 3000# is way under the acceptable limit and would likely cause sway issues.

I disagree.
As you said "generally accepted that 10% to 15% of trailer weight is acceptable" also allows 5% to 30% to also be possibly required to safely tow.
The 10% "rule" is a starting point and yes "generally" a good point. But not always. Of course whatever weight is placed on the hitch must be taken into account as far as the capacity of the tow vehicle.

But yes you don't want 900# on the hitch of an Escort, lets use common sense about it.

I might haul a speedboat and with only 5% tongue weight it sways all over the road at highway speeds. But if I turn the boat over so that I have down force instead of lift, it tows just fine at 100mph.
But common sense says I am not going to haul my boat upside down.
Well, maybe I would if it were a row boat.

 

[Matthew_B]

Re: tongue weight

Silvertip: I'm waiting for the example of a boat that sways from a light tongue. You came up with an example of a utility trailer accident.

My in-laws have a 17' aluminum skiff. It weighs in at about 900 lbs. The tongue weight is around 35 lbs. Never sways a bit.

I have a Glaspar that weighs in around 3600 lbs on the trailer, with a tongue weight of around 120. Also tows nice. Set up from the factory like that. As are thousands of boats just like it I'm sure. The boat is nearly 40 years old and has been towed many, many miles. Also tows real nice.

You started the age dig so I'll throw it back. Old farts have the habit of doing something because that's the way they always did it, whether right or wrong.

 

[Mike722]

Re: tongue weight

This seems more like Dock Side Chat, but Silvertip is right. My opinion from pulling all types of trailers (small lawn mower to large goose neck) is that light tongue weight is a crash waiting to happen.

Some light tongue weight trailers will pull fine and others will not. What I do know is that when they go bad, they go bad quick. I have pulled light weight trailers hundreds of miles and all of a sudden they start whipping.

Emergency stopping is also a problem. You hit the brakes, the front end of the truck goes down, the back end up and you're left with rear tires off the ground being pushed by the weight of the trailer.

My current trailer is a 22ft haul rite with a 20ft pontoon boat. I can lift the tongue by hand because the boat is at the very back of the trailer. The trailer seems very stable going down the road, but it will let loose at higher speeds (45-50) with no warning and you better be prepared for it.

I know it is not safe and I would never let anyone else drive but myself. We have a lift so the trailer is used once a year for a short distance. I do not go over 40 with it anymore. I also made a stand at the back of the trailer to lower when it is not hooked to the truck to keep it from flipping up.

You have to look at the risks and make your own mind up, but in my opinion too little tongue weight is more dangerous.

 

[Matthew_B]

Re: tongue weight

My current trailer is a 22ft haul rite with a 20ft pontoon boat. I can lift the tongue by hand because the boat is at the very back of the trailer. The trailer seems very stable going down the road, but it will let loose at higher speeds (45-50) with no warning and you better be prepared for it.

Again, you bypass examples of boats that can have a lighter tongue and still be stable. A 'toon is more like towing a travel trailer than a I/O or outboard boat.

I love being lectured by someone who tows a knowingly unsafe trailer but tells me what I'm doing is unsafe. I've known the original owner for a while, and he used the boat / trailer combo annually many times for multi hundred to several thousand mile trips. He swears it's always been stable, matching my experience.

You have to look at the risks and make your own mind up, but in my opinion too little tongue weight is more dangerous.

Yep, but you have to define where "too little" is. I keep saying 5-7% is OK for an I/O and 3-4% is OK for an outboard aluminum skiff.

Interesting that Shoreland recommends 6%. Load Rite says 5% to 7%.

And I'm continuing to wait for someone to pipe up that "yeah, I had a I/O boat and it fish tailed on me"