Tongue weight?

[kybishop]

I could not find any information about tongue weight for our 1982 210 Cuddy. I don't need exact, just a close estimate. Boat is not kept on the trailer or I could just go out and weigh it.

I can find the weight of the boat in the archive brochures. Is there a calculation based on weight and type of trailer that will get you relatively close in estimating tongue weight?

Thanks.

KB

 

[Lazy Daze]

Boat trailer manufacturers typically recommend that tongue weight be about 7% of total weight.

However, there is really no way to know what your set-up will weigh without you actually weighing it. We'd all just be guessing. Who set-up the trailer? If it was done by a reputable place, you might assume it was done correctly... but that would only be an assumption. The only way to know is to measure it.

 

[kybishop]

It was set up by Sea Ray. I am the second owner and it was purchased new from Sea Ray at a boat show by the prior owner. It is a tandem easy loader. I keep the boat at the marina so I may have to wait till I get it out next time.

I am having some custom springs made for the truck and tongue weight is something they take into consideration.

Thanks.

KB

 

[OldSkool]

A good reference for any tongue weight is about 60% forward and 40% rear. Doesn't matter what the load is. If you have a 60-40 split and the tongue weight makes the tow vehicle sag then your tow vehicle is too small.

 

[OldSkool]

It was set up by Sea Ray. I am the second owner and it was purchased new from Sea Ray at a boat show by the prior owner. It is a tandem easy loader. I keep the boat at the marina so I may have to wait till I get it out next time.

I am having some custom springs made for the truck and tongue weight is something they take into consideration.

Thanks.

KB

My 76 SRV 200 sits on a single axle trailer and weighs in at 2800 lbs. The previous owner had a 3/4 ton pick up and he was running 80% on the front. Had almost 600LBS tongue weight. I slid the axle forward 18inches and got it to about 60-40 and 300LBS tongue weight. The trailer pulls straight and never fish tails. It has really helped in loading as the trailer geometry is better in relationship to the water line and angle of approach of the boat.

The calculation is not about total weight but more about where the weight is in the boat.

 

[kybishop]

Okay, thanks.

 

[kybishop]

A good reference for any tongue weight is about 60% forward and 40% rear. Doesn't matter what the load is. If you have a 60-40 split and the tongue weight makes the tow vehicle sag then your tow vehicle is too small.

We towed it with my brother's first gen Dodge Cummins so sagging was not an issue. Could hardly tell it was there.

I am starting the build of a tow vehicle with a 6bt Cummins and the spring fabricators were asking about tongue weight.

They are building the springs for the torque of the cummins so the tongue weight rating should be pretty high to begin with. Still, weight distribution on the trailer is key but I feel it is set up correctly as we hardly noticed it back there.

KB

 

[OldSkool]

If you are comfortable with the weight distribution then the best way to get the tongue weight is to weight it with a scale. Call around to your local steel fabrication shops and see if anyone has a crane mounted scale.

Ask them to pick up the tongue just until the wieght is off the ball and then you'll know exactly what you have. You won't even need to disconnect it.

On small trailers we would use a bathroom scale up to 300LBS. Set the trailer down on the landing wheel and there you go.

 

[Lazy Daze]

Are you intending this tow vehicle to only haul your current boat? Or, do you have plans of hauling heavier things? You may want to consider building it to haul something heavier as the engine is certainly capable of it.

 

[kybishop]

Good input, thanks. It is a 1978 Dodge Ramcharger pop top(removeable). The more they build in for higher tongue/load weight, the rougher the ride. I may go with a compromise of a load and tongue weight for the smaller boat with an overload spring they recommend which would easily handle 1000 lbs back there.

KB.

 

[Lazy Daze]

Very true - you certainly don't want to build it to be like a current 1-ton capacity. However, maybe it would be easiest if you just tell them to build like a 3/4 ton suspension. But, I think you're right on the money with your thought - in fact I was thinking the same thing... somewhere between 750 and 1,000 would give a nice compromise.

 

[Henry Boyd]

Boat trailer manufacturers typically recommend that tongue weight be about 7% of total weight.

However, there is really no way to know what your set-up will weigh without you actually weighing it. We'd all just be guessing. Who set-up the trailer? If it was done by a reputable place, you might assume it was done correctly... but that would only be an assumption. The only way to know is to measure it.

Actually, it is really quite easy to calculate tongue weight. Trucking companies do it all the time to figure out axle loadings for bridge law conformance. The trick is getting the background data. You need the following:

weight of boat,
center of gravity of the boat (longitudinal only),
manner in which boat is mounted to trailer; bunks, rollers etc. and their dimensions,
location of the boat center of gravity with respect to center of each trailer axle,
distance between axle centers,
distance to tongue,
If we were doing something really big like a semi, we would also need to have the basic weight of the trailer itself. That would have to be weighed, unless you had the weights and locations for each of the major components. But since we are talking about a boat trailer with a total weight of worst case 1200 pounds and a tongue weight of maybe 75 pounds, its close enough for horseshoes.

After that it is a simple (sophomore engineering statics) calculation to determine the bending moments.

Henry

 

[Prater]

If you are near a truck stop with certified scales you can get an acurate tongue weight. You pull the boat onto the scales with your rear truck tires on the first pad and the boat on the second pad. Get a snapshot of the weight and then drop the boat off in the lot and pull across a second time to get a snapshot of just the truck weight. On the snapshot there will be three or four seperate weights and then a tallied weight. Take the first pad weight with the boat attached and subtract the weight of your truck and you will have the tongue weight. If you just want a close weight then just get the gross weight of your truck off the door sticker and your body weight and subtract that from the first pad snapshot.

I believe the certified scales will have three or four pads to pull on. Each pad is a seperate scale so it's important that only your tow vehicle is on the first pad. Last time I did this it cost about 20 bucks.