Trailer capacity; a cautionary tale

[Falco]

I have a 2004 22' on a tandem axle King Trailer (KBT4000B2), both purchased direct from the factory. The trailer is the second trailer under the boat, the first being swapped out by King when the boat was at the factory a few weeks after purchase to have the engine mountings adjusted. The King rep said the trailer "was not right for the boat". I could not tell the difference between the two trailers.

When driving over highway sections which have been trashed by semis, I have noticed my truck (04 Tundra) and trailer bounce/hop/vibrate so much I have to slow to 40-45 MPH and recently almost lost an engine cowling due to it popping off the engine during transit over that section of I-5 south of Federal Way (locals know what I'm talking about). Thinking there might be a problem with weight distribution of the boat on the trailer, I took my rig to the local scales (Cadman, one of the largest suppliers of sand and gravel in the Seattle area, digital scale) and weighed each axle. The results were interesting and very disconcerting.

Note the trailer sits perfectly level when it is attached to the truck.

Problem #1: the weight of the boat is not distributed evenly over both axles; the main load lies forward of the front axle. The front axle carries 860# more than the rear, ie, 43% more than the rear axle. (Note tere is nothing heavy or out of the usual in the forward section of the boat. The cuddy is essentially empty and I only use 20' of 5/16 chain on my rode.) The GM at King says this is "no big deal" as each axle is rated for 3500# and to rotate the front and rear tires often as the fronts will wear out sooner than the rears. I'm not so sure this is optimal. He also suggested raising the hitch to transfer some weight to the rear axle. I may try this although: a) this will make the trailer unlevel (and I have always heard this is a no-no) and b) this may decrease tongue weight below the King-recommended 5-7% of total trailer weight. The current tongue weight is 6.9% of the total boat/trailer weight. Bottom line: the boat is not set up correctly on the trailer and never has been. This is a problem I will have to fix - probably by moving the axles around on the trailer - at my expense.

Problem #2: the weight of the boat exceeds the GVWR and rated carrying capacity of the trailer by 3% and 3.5% respectively. Trailer loads should NEVER exceed about 85% of GVWR and load carrying capacity. My set up is about 18% over spec. This is a very serious problem and one which could result in loss of life or limb. The GM at King denies any responsibility here, saying they sell trailers to C-Dory who does with them as they see fit. The King GM suggests that by switching out the tires on my trailer (to load rating C from B) and swapping the winch for a higher capacity, the trailer will actually have a higher GVWR - about 5640#. Unfortunately this would still not give me the 85% cushion. I will probably need to go to load range D tires. The trailer frame, according to him has a GVWR of 7000#. A set of 5 new tires for the trailer will cost at least $450+installation. My boat , with a full, ordinary load (I carry nothing unusual) weighs 4140#. Bottom line: the trailer is too small for the boat and not fitted to the boat. I will have to correct this problem at my expense.

Key learnings:

1. Folks often ask about what to look for when checking out their new C-Dorys. Add to the list: run a weight check (see below) and get in touch with the factory if the boat (fully loaded or as calculated) exceeds 85% of trailer GVWR (the GVWR is stamped on the trailer). I also suggest you either: a) have the factory/dealer provide you with tongue and axle weights upon delivery or b) have the factory/dealer write on your sales receipt that the boat, with an ordinary complement of fuel, water and gear, is properly positioned on the trailer and will not exceed 85% of the trailer's GVWR and carrying capacity. New owners should also drive their rigs over "bumpy" highway sections to check for uneven weight distribution.

2. For folks who have boats on trailers, consider running them across a reputable set of scales. I've seen posts here that question the accuracy of large scales. Call ahead and find out - every scale has a accuracy rating. The ones I used are accurate to with 20 pounds and are inspected twice a year.

Calculating weights is easy. The following presumes the scale you are using is long enough to accomidate the towing vehicle and boat (and not just one axle at a time). Hook up the boat to the vehicle. Drive the first vehicle axle onto the scale and get the weight ("VBT1" for Vehicle, Boat and Trailer, axle 1). Drive the second vehicle axle onto the scale and get the weight (VBT2). Drive the first trailer axle onto the scale and get that weight (VBT3). Drive the fourth axle on the trailer (if so equipped) onto the scale and get the weight (VBT4). This last weight is the total weight of the vehicle, boat, trailer. Drive off the scale and disconnect the boat. Drive the vehicle onto the scale and get both axle weights (V1 and V2)

Total V1 and V2. This is the weight of your vehicle ("V").

Subtract V from VBT to get the weight of the boat and trailer (BT).

Subtract the weight of the trailer ("T" - stamped on the trailer or calculated by substracting trailer carrying capacity from GVWR) from BT to get the weight of your boat ("B"). Add to B any ordinary trailering load not present on the boat like gas (6.5 pounds per gallon) and water (8.3 pounds per gallon), beer (dunno weight per gallon but it doesn't change when ingested).

Subtract V from the weight of the second axle weighed with the boat (VBT2) to get tongue weight.

Substract VBT3 from VBT2 to get the weight load on axle 3.

Substract VBT4 from VBT3 to get the load on axle #4.

Consider making changes (eg, buying higher load range tires) if you find problems. Blow outs can be a real safety issue.

Calculating the main load point (center of mass) of the boat and trailer relative to the axle positions is more difficult. I had a PhD calculate mine. Probably any college engineering student could do the same.

Sorry for the long post. Hope it helps.

[Byrdman]

FALCO: So....help me with what the folks at C-Dory factory said please. Did you get in contact with Jeff or Scott?

[Larry H]

Falco,

I had similar problems with my Pacific trailer. It is a 5,000 GVWR trailer and a scale showed it to be 100% loaded when the boat had no fuel and little water, and not much equipment. The tires were also load range 'B', long since replaced.

I think the correct trailer for a 22 is a 6,000 or even 7,000 lb. GVWR trailer.

[Yellowstone]

Falco - I'm going to share some opinions with you on some trailers for the 22' Cruiser. It comes from ten years experience pulling the cruiser thousands of miles over Interstates, secondary highways, good, bad, and indifferent - one time over gravel roads for 50 miles to reach a remote but huge lake (Fort Peck with 1,500 miles of shoreline). My first trailer was a mistake. It was an Easy-loader 3,100 # rating single axle with torsion suspension. The cheap tires wouldn't hold up and the roller assembly rods began to crack. My second trailer was an Easy loader 3,700 # rating with single axle torsion suspension. The only problem encountered was the rear through bolt holding the cross member to the frame. One broke on a trip. Easy-loader does not put hardened bolts in their cross section of their frames. It is an easy retrofit and inexpensive to replace the bolts with the hardened variety, something I would strongly recommend to anyone with an Easy-loader trailer. I can't speak for other trailer makes. I had one blowout with the 3,700 lb trailer while going 60 mph. No problems at all, but it may be a function of my towing rig, which is real overkill but greatly comforting to me. an extended cab F250 4 wheel drive with 7.3 liter diesel. The cruiser tows beautifully, no fish tailing, bouncing or skipping. Single axles simply tow better than dual axles, and the Goodyear Marathon tires - 225/75/15 - are rated D with a combined weight bearing capacity of over 5,000 lbs and are up to the load of the C-Dory and trailer. Your towing rig may be part of your problem with the bounce you describe, not just the road since with torsion suspension, the boat and trailer just dip through the rough spots. Also, I reduce the load of gas and water when I travel (providing the destination can provide those) and that can translate easily into 400 lbs less weight on the trailer. This a pretty complex topic since road conditions, towing rig, and trailer all combine to interact with each other.

John

[oldgrowth]

Falco - something does not add up here. If I am reading your post right , your total weight is 4140 lbs.
Front axle is 860 lbs heavier than rear.
Front axle is 2500 lbs or 60% of total weight.
Rear axle is 1640 lbs or 40% of total weight.
2500 – 1640 = 860 (difference between front and rear)
60% - 40% = 20% (difference between front and rear)
6.9% x 4140 = 286 lbs (your tongue weight)
Recommended tongue weight 5% to 7% (207 lbs to 290 lbs)

Looking at these numbers it doesn’t look like you are that far out of balance.
You have to have more weight on the front axle to have tongue weight. If you are concerned with the front to rear axle ratio, move the boat back a few inches on the trailer and keep the tongue weight within that 5% range.

I do believe you are right about the need for heavier tires.

[Best Day]

Falco,

Reading your post it is a little unclear are you saying your boat rigged weights 4140 pounds or your boat rigged with trailer weights 4140 pounds?

Yellowstone,

I've only trailered a single axle before but was under the impression that dual axles trailered better because they had more tires to spread the load and help prevent the weight from shifting forward and backward.

Bill

[Les Lampman]

I want to stop this thread in its tracks before it gets out of hand. I appreciate very much that folks want to help each other but this is a potentially dangerous thread and I'd not feel comfortable if I didn't speak up and help here.

There is a lot of misinformation or at least misleading information in the post that started this thread. I am NOT (most certainly not) saying anything disparaging with regards to the author; I am only responding to the information presented there.

The weight rating given by the trailer manufaturer is carrying capacity, it is not GVWR; GVWR means nothing as you can't exceed it if you don't exceed the the carrying capacity given by the manufacturer. The King 4000# trailers are rated to carry up to 4000 pounds of load continuously (and conservatively). Just as the EZ-Loader single axle trailer is rated for its max capactiy of 3700# on a continuous basis. The fact is that usually the axles are much heavier then they need to be because of shared components on various models of trailers. It turns out the frames are as well; they're often shared so that there are several models avaialbe on the same frame. Such is the case with the King 4000 which comes in a 4600 model as well on the same frame and axles. Typically weights are limited by tires as much as anything else (and the number of rollers on roller trailers).

If your boat doesn't exceed the carrying capacity stated by the manufacturer and it does exceed the GVWR then the manufacturer got it wrong and should rectify the situation. Typically the stated GVWR is the carrying capacity of the trailer plus the weight of the trailer. There's a lot of safety cushion there as the trailer (based on frame size, tires and axles) could be rated much higher...but if they did that someone would use it to justify carrying more load then intended..."because the sticker said I could"!

Sharing weight equally between multiple axles with torsion suspension is important no matter who makes the trailer and regardless of whether it's a boat trailer, a travel trailer, a car hauler or whatever. Generally speaking you get pretty close when the trailer is level but if not you can adjust the hitch height to even things out; there's nothing that says the trailer has to be level (it's just a starting point for load sharing).

I generally shoot for 10% of the all up towing weight to be on the tongue. If your tow vehicle won't handle this it's too light for the application or the suspension needs help (we're only talking about 400 pounds or so for the CD22). Getting down to 5% to 7% is a "minimum"; more is better (there's no maximum as long as the tow vehicle can comfortably handle it). Too light a tongue weight usually results in a lot more pitching since it's easier for the tongue to swing through an arc up and down. Also, if you've got an appropriate tow vehicle the light tongue weight won't allow the suspension to work well. The light weight tends to let the vehicle suspension rebound too easily and things hobby-horse.

Unless you're pulling a short-coupled trailer (not typically the case with boat trailers) or you're very underweight on the tongue, handling issues are in the tow vehicle (or coupling) and not the trailer setup. There's no substitue for tow vehicle weight and wheelbase length; most folks don't realize how much influence the wheelbase of the tow vehicle has on the stability of the package. It's the dog that keeps the tail where it belongs rather than vice versa.

I hope this helps everyone understand the numbers. In a nutshell if you don't exceed the manufacturers carrying capacity you're good to go....that's what the rating is for (if they intended otherwise they'd just throw the other numbers at you and make you do the math). Of course, you're going to make sure your tires are aired correctly, that the hitch weight is correct and that the load on the axles is evened out.

[Sawdust]

On the road again! This is almost like single engine vs twins.
I personally much prefer the dual axle setup and I have both -- but agree with Yellowstone - the tow vehicle has a whole lot to do with the package.

Too much trailer is bad also -- not sure where the 85% load recommendation came from, but it sure makes sense. I don't get near that.

Dusty

[Byrdman]

Good Job as usual Les.

Am I the only one to wonder why all the print on the sidewalls are 1/2" and larger for all the BS that is on the side of a tire.....and that number that you really need to look at..... "just how many PSI do I put in this sucker when she is cool....."..... is in those little bitty mirco print size.

Just a thought.

Byrdman

[Yellowstone]

My statement about single axle trailers towing better was really too dogmatic to past muster, I must admit. I needed to qualify my opinion as it regards to the 22' cruiser. The 3,700 # Easy-Loader single axle with torsion suspension is a perfectly adequate trailer for the 22'. True it doesn't have the redundancy of a dual axle, but I watched a number of dual axle trailers carrying 22- Cruisers, and they seemed to wiggle sideways more. In my 50 years of pulling stuff, which includes several dual axle and one triple axle travel trailer, I found them to have problems, too. It is the rare multiple axle trailer which has the axles in alignment, the tires in balance, and everything working together. If redundancy gives comfort, go for it.

[Sawdust]

It's a coin with two heads!! Single axle will do the job with 1/2 the stuff to fix. Wheel bearings, brakes, extra plumbing etc. And a whole bunch of etc. A whole lot easier to get the right weight on the tongue -- no problems with trying to get equal weight on the extra axle. Must agree that allignment is a real problem with a dual axle trailer - I have that problem now and a ruined tire to prove it.

The dual axle does give another set of brakes in a panic stop and provides a way to get to a repair facility if you blow a tire... BTDT a few times. Because my tow vehicles are monsters, I've never had a tail-wagging-the-dog situation, even with the 18-wheelers going by at warp speed. I stiffen up the rear of the tow vehicle with air shocks and pump up the rear tires to max. Radials do get sloppy if under-inflated. Of course all of the dually guys just drive along and don't know ther's a boat behind.

So take yer choice. My choice, for a whole lot of reasons, is to keep the boat in the water and park the traiiler out back! Wonder if that could be age related, like hearing, eyesight, and other stuff.

Dusty

[starcrafttom]

I will take a flat on a dual axle trailer over a single any day of the year. i have changed a lot of flats , mine and others, and hate doing it on the side of the road.

[Falco]

Just a couple of points:

1. Thanks for all the feedback. I am interested in learning as much as possible and hope this thread is never "stopped in its tracks".

2. I disagree my initial post contains any misinformation. If anything I tried to put as much data in the post as possible. I also disagree tyhis post is dangerous. It's clear intent is to improve safety.

3. The boat (only), loaded, weighs 4140 pounds. This is 540 pounds (or 15%) OVER the rated carrying capacity of the trailer. This is calulated as follows. The trailer label clearly states the carrying capacity is 4000 pounds. THE KING WEB SITE STATES: "The PROPER trailer for your boat will carry the fully loaded weight of your boat plus approximately 10% overage for safety purposes" (emphasis added). Hence the "actual" or "working" carrying capacity of the trailer is 3600 pounds to allow for the "10% overage for safety purposes". I don't believe this is "misinformation"; it is fact.

4. The total weight of the boat and trailer is 5180 pounds (sorry I should have put this in the initial post). 5180 pounds is 140 pounds over the trailers printed GVWR - again as shown on the trailer's label. Note the trailer label lists BOTH GVWR and carrying capacity; I have not confused one with the other. This is about 3% OVER the printed GVWR of the trailer. The "85% safety factor" re: GVWR comes from BoatUS.org (http://www.boatus.org/onlinecourse/ReviewPages/BoatUSF/Project/info3c.htm see "Part 1 -Trailer Size". I presume at least most of us can agree this is probably a reputable source of information. Taking this 85% margin/factor into account the "actual" or "working" GVWR rating of the trailer is 4284 pounds. My boat and trailer are 896 pounds (21%) OVER the "safe" GVWR of the trailer. I don't believe this is "misinformation"; it is fact.

5. I learned from the folks at Les Schwab tires that load range "C" (6 ply) tires will give the trailer a 7000# capacity. This jives well with the King Trailer GM's statement that the trailer and axles are actually rated for 7000 pounds - it's the tires and winch that "down rate" the currenty trailer. All FACTUAL indications are that putting load range "C" tires on the trailer will make it a safe and suitable trailer for my boat. Dealing with the load balance is another matter.

6. I can't comment on tandem vs. single axle trailers other than to say by tandem tows like a dream expect for the bouncing on those sections of hiway frequented by semis.

Again, I hope this information is useful. If you take issue with the FACTS, please let me know. I want to learn. I want my rig to be safe.

[Larry H]

A comment about tires and carrying capacity.

I replaced my tires with Goodyear Marathon 205/75 R14 load range 'C'. Load capacity 1760lbs each.

On my tandem trailer this gives an axle capacity of 1760 lbs x 2 = 3520lbs per axle x 2 axles = 7040lbs. Subtracting the trailer weight of 850 lbs equals a carrying capacity of 6190lbs for the axles and tires.

However the GVWR has not changed. The id plate says 5,000lbs GVWR, so I have an excess tire and axle capacity of 1190lbs or 23.8%. A good safety margin!

Note that the actual (legal) carrying capacity of the trailer has not changed. It is still 5,000 lbs GVWR less trailer weight of 850 lbs, for a carrying capacity of 4150lbs.

The GVWR stated on the id plate is the limiting factor. If the trailer was to be involved in an accident, thats what the patrol (and insurance co) would look at.

[iggy]

This is a most interesting thread. I sincerely hope it can continue logically and rationally. We need to hear everyone's well-thought opinions, along with the facts as can best be determined.

I am still a CD wannabe, so this thread is of immense concern to me. Over the past six months I have been trying to learn as much as possible about boats in general (C-Dory's in particular), and about safe trailering practices. It is more than a little disconcerting that there should continue to be this much confusion over such an important issue.

In my various inquiries I have asked several dealers (various brands, locations, etc.) about boat weights, trailer weights, etc. In the vast majority of cases I receive a lot of hand-waving in return. This does NOT instill confidence!

I understand the liability issues in handing out incorrect information. I can also understand the reluctance of the dealers to 'give me a number' -- I might take it as gospel, misinterpret it, run into trouble, and then come back with, "But you said . . . ".

We have a Ford Explorer. When I started I had NO IDEA how much a boat/trailer combination weighed. Am I in the ballpark? Out of the question? Do I need a new vehicle as well as a new boat?

I fully realize the ultimate responsibility is mine. On the other hand, when I see a boat sitting on a trailer at the dealer, and I ask, "How much does that weigh?", I'm not looking for a bunch of hand-waving! GIVE ME A NUMBER! THEN we can talk about fuel, water, batteries, etc., etc., etc.

Next, and even more useful, I'd like to KNOW what a "typical" load would be going down the road, for the same boat. Again, the ultimate specs become my responsibility. But at least give me a starting place!

Here are two useful sites I found:

1. http://www.catscale.com/

These 'certified' scales are designed to measure multiple axles, including trailers. They look PERFECT for the answering many of the problems at hand. Unfortunately for Falco, the nearest one appears to be in North Bend. Perhaps other local scales can be found that would be as flexible and as accurate . . . ?

2. http://www.trailerboats.com/
This has a LOT of information about setting up your tow VEHICLE, but as I just reviewed it again, it does NOT talk about trailer specs!!! (See what I mean . . . ?!).

In my opiniion it should be ILLEGAL to post "dry-weight" specs in the mfg/sales literature! At the very least, the boat should be filled with gas and water, minimal (necessary) batteries, engine (WITH oil!), and perhaps a 'standard' anchor and rode. This weight should be CERTIFIED correct (+/- some %). I would not expect the dealer to be obligated to do this for each and every boat (although that would be nice . . . ), but the mfg should be -required- to provide this information to the general public.

And I haven't even begun to talk about trailers . . . !

The questions raised in the original message, and amplified later, certainly seem to be well-thought-out to me. I would have the same questions, and frankly, as a wannabe, I will certainly move forward ONLY AFTER resolving all these same issues in my own mind.

-- Is the trailer rated at 4000 lbs, or isn't it?
-- How much does the LOADED BOAT WEIGH? Weigh the entire rig. Then weigh the same rig w/o the boat. (Why can't C-Dory give us these numbers???)
Does putting better tires on it raise the GVWR, or doesn't it?
If so, how does one get a 'corrected' placard, for legal/liability peace of mind?

The list goes on! Inquring minds want to know!

If we are misinterpreting the situation, this needs to be clarified. If the trailers leaving the factory are below safe (REALISTIC) specs for a 'typically loaded' boat, we need to know that, too.

(Quite frankly, I am NOT looking forward to a 'he said (factory) - she said (trailer mfg)' type of explanation. I already have to deal with such issues ad nauseum with PC hardware/software vendors . . .

(BTW; I 'might' be able to pull a CD-22 with the above-mentioned Explorer, but it appears to be marginal. Of course I don't really know for sure, because the 'facts' continue to elude me . . . An Explorer/CD-25 (with that enclosed head my wife keeps mentioning) is clearly beyond consideration.)

Thanks to all for the tremendous knowledge base contained within these forums. I look forward to some clear resolution of these critical issues.

e.g.