Dual vs triple axles...

[Prater]

I have both a tripple and tandem axle. I like both, they both have their advantages and disadvantages. But like my southern neighbor in Texas, if I had my way my tripple would be a tandem dually. I should have spent the extra for axles when I ordered my new tripple 6K pounders. Look into electric over hydraulic brakes for your upgrades also...just my few pennies.

 

[Daddubo]

Generally on RV trailers it is springs and tires that make the difference I have 9.50 X16.5 10 ply tires on mine springs are questionable but there is very little deflection on the tires.
On commercial there so many variables single tire, dual tire, spring rate axel and tire size.

You might want to be a little conservative with that assumption. I'm not sure about axles for recreational trailers, but I do know that the axle rating numbers on axles used for commercial trailers are somewhat theoretical. For example, a Meritor TQ axle that is rated at 30,000 pounds, can be 'de-rated' by as much as 10,000 pounds just by the choice of bearings, brakes and location of suspension components.

So the counter guy may be correct in telling you the axle has a 6,000 pound rating, but it is only the trailer builder who can tell you what the actual GAWR is.

Henry

 

[Henry Boyd]

Generally on RV trailers it is springs and tires that make the difference I have 9.50 X16.5 10 ply tires on mine springs are questionable but there is very little deflection on the tires.
On commercial there so many variables single tire, dual tire, spring rate axel and tire size.

You are right about commercial axles, but one big factor is the placement of the springs. All other things being equal, the distance between the spring hangers is a big factor in the the actual axle rating. The closer the hangers (or air spring mounts) are to the wheel end, the higher the axle rating. So there is some overlap with the recreational trailer. Basically the trailer body itself influences the location of the springs in both cases.

An axle manufacturer that does the engineering (as opposed to an axle manufacturer who copies everybody else's design) will provide the trailer builder with a spec that will outline the adjustment to stated axle capacity as it relates to spring hanger attachment location. So that is why I say the trailer manufacturer is the only one who can say for certain what the axle rating really is.

No question the tires and springs on boat trailers are the weak link. Mainly because they are being loaded at the top end of the loading spectrum. They problem is that to use tire and springs that would support these kinds of loads would not be an acceptable solution.

Henry

 

[phoenixhotrods]

I just bought a 1987 270, and am building a trailer for it. Would you go with dual or triple axles and bumper or fith wheel hitch?
how did you like your 270? this is our first boat.

 

[Henry Boyd]

I just bought a 1987 270, and am building a trailer for it. Would you go with dual or triple axles and bumper or fith wheel hitch?
how did you like your 270? this is our first boat.

No offense is meant with the following comment. I have been in the business of engineering transportation equipment for more than 35 years. A trailer for a large boat, such as a 270 is a very problematic vehicle to build. The combination of boat weight, road regulation and physical dimensions gives the designer a very narrow margin of safety between a safe design and a flawed one.

If you have to ask the above questions, you probably should not be trying to build the trailer. There is more to this than just having the skill to fabricate it.

Henry

 

[OldSkool]

No offense is meant with the following comment. I have been in the business of engineering transportation equipment for more than 35 years. A trailer for a large boat, such as a 270 is a very problematic vehicle to build. The combination of boat weight, road regulation and physical dimensions gives the designer a very narrow margin of safety between a safe design and a flawed one.

If you have to ask the above questions, you probably should not be trying to build the trailer. There is more to this than just having the skill to fabricate it.



Henry

I agree with your reply.

This is not a flat bed trailer that hauls weekend building material. Center of gravity, front to rear weight ratio, bunk width and keel height, bow stop to end of tongue length and tire/spring type and number are just a few items that go into a boat trailer. Will your beam require extra bunk supports? Will you use rollers or bunks?

The rails should be form bent to meet at the tongue after running from the bunks and length of the boat. If you are fabricating this bend then make sure there is enough fish plating to support the bend and that you have enough tongue to absorb flexing without putting undue stress on the weldment. These are important for any size boat trailer and are more critical on 25+ foot boats.

I have not seen any fifth wheel trailers being used except for boats that use a crain to splash them. Nice to be able to walk out on the tongue to hook up if loading condtions are not good. Sometimes I need to walk the boat in so the tongue becomes my cat walk.

Best of luck if you decide to go forward. Best thing to do would be to search for a good plan on the web before starting.

That's my pretaxed 3 cents.

 

[D9ever]

http://clubsearay.com/forum/album.php?u=19485

I have a 2000 340DA. Could have purchased a 3 axle but considering the weight of the trailer and boat(13,000# for boat alone) I chose a 4 axle for the extra safety and lighter tongue wt. I have electric/hydraulic brakes on all 4 axles. Tow with a 2009 DodgeHD Diesel Dually. See pics of the trailer with boat on the included URL

 

[OldSkool]

http://clubsearay.com/forum/album.php?u=19485

I have a 2000 340DA. Could have purchased a 3 axle but considering the weight of the trailer and boat(13,000# for boat alone) I chose a 4 axle for the extra safety and lighter tongue wt. I have electric/hydraulic brakes on all 4 axles. Tow with a 2009 DodgeHD Diesel Dually. See pics of the trailer with boat on the included URL

Seen your picture, what is your tongue weight, 50LBS?!:smt043:smt043

 

[magster65]

From my experiences...
Handling is a no-brainer... the singles handle in tight turns best, then the tandems then the tri-axles. Durability, the tri-axle wins hands down and it stops and tracks better. The downfall with more than one axle is tire scrub in tight turns and maintenance.
For myself, I would prefer a tri-axle on everything over 6000 lbs.

 

[garryowen]

http://clubsearay.com/forum/album.php?u=19485

I have a 2000 340DA. Could have purchased a 3 axle but considering the weight of the trailer and boat(13,000# for boat alone) I chose a 4 axle for the extra safety and lighter tongue wt. I have electric/hydraulic brakes on all 4 axles. Tow with a 2009 DodgeHD Diesel Dually. See pics of the trailer with boat on the included URL

i run a 4 axle under our 310 also. ele. over hyd discs on all 4. pull with a 2500 H D dura max
wouldn't have it any other way.
not sure some one, not form the west would understand.

 

[Banagy]

Consider backing with about 75degree angle with both axles,

 

[phoenixhotrods]

No offense is meant with the following comment. I have been in the business of engineering transportation equipment for more than 35 years. A trailer for a large boat, such as a 270 is a very problematic vehicle to build. The combination of boat weight, road regulation and physical dimensions gives the designer a very narrow margin of safety between a safe design and a flawed one.

If you have to ask the above questions, you probably should not be trying to build the trailer. There is more to this than just having the skill to fabricate it.

Henry

Dude, I build 250,000 dollar cars, some are at Barret Jackson, im sure i can build a boat trailer.
I always probe people to see how much they know and how much is B.S.
Why do Engineers always put an oil plug where its hard to get at?
maybe they should have some hands on training before they build something.
No offense.

 

[Don Sr]

Dude, I build 250,000 dollar cars, some are at Barret Jackson, im sure i can build a boat trailer.
I always probe people to see how much they know and how much is B.S.
Why do Engineers always put an oil plug where its hard to get at?
maybe they should have some hands on training before they build something.
No offense.

Geez you ask advice then, then critize advice from someone who's engineers this type of equipment. No offense dude.

 

[Lazy Daze]

Dude, I build 250,000 dollar cars, some are at Barret Jackson, im sure i can build a boat trailer.
I always probe people to see how much they know and how much is B.S.
Why do Engineers always put an oil plug where its hard to get at?
maybe they should have some hands on training before they build something.
No offense.

So, you asked a "loaded" question just to "check and see" what people know? If you do indeed have the experience and expertise needed to do this build, then you should already know the answers. Sounds a little on the sneaky side.

Maybe it's just the way you worded your statement, but be careful as you might find that some guys on this board will end up ignoring you when you have a real question... and these guys are the exact ones you would want answering your questions as they are true experts in their field.

 

[phoenixhotrods]

Thanks, I enjoy talking to a straight shooter. Who out here builds searay's or owns a trailer manufacturing co.

Thats who id like to talk to. As you know in business the experts arent always right, its the guys that operated this type of equipment day in and out. In my business experts have been wrong many times, so i guess if i ask a question about a trailer, if someone knows (or is an expert) they should be able to help a guy find the c of g or tounge wieght per ft.
I dont think that that is to much to ask for an expert. Is it???

 

[D9ever]

Seen your picture, what is your tongue weight, 50LBS?!:smt043:smt043

Ran it over the scales--Truck, with 1 person and full tank(36gals) is 8030. Boat is 13,240. Tongue is 1070

 

[Henry Boyd]

Thanks, I enjoy talking to a straight shooter. Who out here builds searay's or owns a trailer manufacturing co.

Thats who id like to talk to. As you know in business the experts arent always right, its the guys that operated this type of equipment day in and out. In my business experts have been wrong many times, so i guess if i ask a question about a trailer, if someone knows (or is an expert) they should be able to help a guy find the c of g or tounge wieght per ft.
I dont think that that is to much to ask for an expert. Is it???

Here is a link you should read:

http://www.truckaccidentlawyerblog.com/2008/01/a_trucking_case_that_helped_br.html

The back story is that the trailer, a container chassis built by a now defunct company in Texas, had been built by people who did not design anything. They were basically steel fabricators who said, "Heck, we build bridges, how hard could it be to build trailers". So they went out and bought a couple trailers, copied them and went into business 'building' trailers. The cause of the accident was that they welded the mudflap and light box bracket to the frame web. It was an obvious mistake to anyone who knew anything about trailer design.

Building show cars does not qualify you to build a lightweight tube type trailer that will carry a 10,000 pound concentrated load. Oh you can fabricate it, but then with enough training I could get 12 monkeys to do that. The point that I was making is that properly building a trailer of the caliber to carry a boat the size of a 270 is something that should be left to the experts. This is for the simple reason that if you don't know what you are doing you will make mistakes. In this game a mistake can easily kill six kids.

Henry

 

[Lazy Daze]

Thanks, I enjoy talking to a straight shooter. Who out here builds searay's or owns a trailer manufacturing co.

Thats who id like to talk to. As you know in business the experts arent always right, its the guys that operated this type of equipment day in and out. In my business experts have been wrong many times, so i guess if i ask a question about a trailer, if someone knows (or is an expert) they should be able to help a guy find the c of g or tounge wieght per ft.
I dont think that that is to much to ask for an expert. Is it???

Sea Ray has never built a trailer (at least as long as I can remember) - they use other companies (EZ Loader years ago, ShoreLand'r for the last 10 years) to build the trailer for them. Usually only up to about a 26' bowrider. To date, I am not aware of anyone on this board that works for a trailer manufacturing company (I could be wrong) - whether it be EZ, Shore or others. However, if there was, I would suspect they may be hesitant to give you answers due to liability.

 

[BlewByYou88]

Sea Ray has never built a trailer (at least as long as I can remember) - they use other companies (EZ Loader years ago, ShoreLand'r for the last 10 years) to build the trailer for them. Usually only up to about a 26' bowrider. To date, I am not aware of anyone on this board that works for a trailer manufacturing company (I could be wrong) - whether it be EZ, Shore or others. However, if there was, I would suspect they may be hesitant to give you answers due to liability.

Back in the day out here (West), you can find many Sea Rays on Trail-Rite Trailers. They are out of Santa Ana California, and still in business. They built custom trailers specifically for Sea Rays' lines. Mine has held up well, I'm about to convert it over to electric brakes.

 

[Daddubo]

I believe there are a few others on this site that have built trailers but never got this kind of response, but it might be because they never ask for any advice. I guess some times you have to watch what you ask for you might get it.