Trailer Design - Matching Trailer To Boat For Proper Support

[CarolinaBurt]

I just read through one of my favorite threads and it struck an old and familiar nerve... What Is Proper Hull Support?

I've owned about 20 boats - everything from 12 foot Jons, 20+ foot pontoon, Jetskis, to my current Allison and stick-steer skiff, in various constructions and designs of fiberglass, wood, and aluminum. Some of those supported with long bunks, some rollers, some with high-tech composite pads. Some had the keel supported and used as the main support while others supported beside the keel and sides. No two of them were identical with regard to how the "Bow Stop and Strap" fit the boat. In fact, my Allison is the one I question the most - I have never liked the idea of winching the bow "tight" because the strap pulls the bow down into the front roller and enacts more pressure "down than forward" when the Eye nears the Bow-Stop.

Has anyone talked with Darris on the subject of perfect support? My XB2002 and the BoatMate trailer were purchased brand new. The bunk supports are fixed and it still has the original carpet and Fur Bunks BoatMate built it with. When I visited the Allison factory several years ago, Nancy took me through their operations - (exception being the Mold Room which I was told was closed to non-employees).

Darris designed the keel, knee braces, transom, and stringers - we know he has absolute direction and design intent for support. Should the Bow Stop/Strap pull down? Should it pull forward? I ask this because when pulled tight, all flex of the trailer is taken away by the boat being pulled tight down into the b\Bow Stop and Strapped down at the Transom. Should the keel stay in contact with rollers (as mine does on the front 2 of 3) or should they "clear" and provide only bumper protection for the keel/bow entry during loading/unloading?

Based on the previously mentioned thread, I know I'm not alone - Where and How should our boats be supported? My thoughts say a Bow-Stop should stop forward motion, not pull my boat further down into the trailer and take away all Flex, but what do I know.

Someone has a drawing! Thanks in advance - Gordon

 

[GotMyAlly]

From what I've seen, I tend to think the manufacturers that build their own trailers (like basscat) achieve a little better fit than manufacturers that attempt to customize a generic trailer frame to their hull.

There's also a big difference in using a trailer as a dolly essentially vs making regular long distance hauls with it. Any ol trailer will work for short distances or near static storage. For long hauls on a regular basis, a little more care needs to be taken to ensure a proper fit. I also believe with materials like wood and carpet in use, the fit is prone to change over time. Checking clearances on the trailer should really be part of annual maintenance.

To answer your question of how the boat should be supported by the trailer, the manufacturer should provide that imho. However, in the case of our boats, I'm not sure you'll find many owners that agree with the factory fit.

 

[CarolinaBurt]

Just a little math to think about - my BoatMate trailer's Bow-Stop is fixed/stationary as are the bunks and rollers - all supports are "welded in-place" as supplied with my XB2002.
The last 4" of Bow-Stop winching starts pulling the bow eye "down". Now, my winch is a 1,500 lbs capacity so let's assume that at even modest tension, I exert just 100 lbs of downward force at the Bow in an effort to maintain contact, if the nearest bunk support is 5 feet away - we have added/applied an additional 500 lbs of torque/tension to that bunk-roller support system.

How many people will/would actually turn that winch until all gap and space between Bow and Bow-Stop is closed by tightly winching that bow to the stop completely? How many store their boats that way for long term with the winch under that 500 lbs (or more) tension? I think it's wrong and I don't pull mine tight - I make sure my loading is fully on the trailer and the Bow-Eye is even with the Stop, but I quit trying to pull the bow down into contact with the Stop years ago. I have a short chain/hook that attaches to the trailer tongue and up to the Bow-Eye. The chain is not under tension, but would keep the boat from bouncing up/back in the event my Strap failed - something I learned about in a boating article many years ago.

More inputs and opinions, please - Gordon

 

[FloridaGS]

Notice when you crank it all the way down how the trailer flexes downward. Never seen that on any other boat trailer I have owned. I do not crank it down, but wished the nose was on a bumper. If the front bumper could adjust we would not have this conversation...so how can we make it adjustable without cutting it off?

 

[scj]

The brand new XR I bought this year had perfect trailer to boat relationship until I hung the engine on the back. Not only did it raise the bow away from the front roller, it only had about five pound of tongue weight afterwards. I raised my bunks (more so in the back) and that allowed the boat to slide about an inch forward and leveled the boat to where there was no downward pressure when winching the boat. Still not enough tongue weight but better than before.
Boatmate's trailers flex too much for me, even with tandem axles underneath (my trailer was tandem btw). They need to stop their production for a minute to do a little engineering IMO.
We've all seen the little exercise with the model car and trailer on a conveyor that shows the importance of tongue weight and myself, I've owned a lot of trailers and hauled a lot of heavy equipment over the years and proper weight placement of the load is extremely important to your safety. I don't believe Boatmate has ever exercised actual testing when they produce any trailer for differing boat models or I would not have had the issues I had recently. Someone proves their accident was a result of the trailer manufacturer's neglect, it would be the end of them. Worse, it gets someone injured.

 

[ROBERT CROSS]

The brand new XR I bought this year had perfect trailer to boat relationship until I hung the engine on the back. Not only did it raise the bow away from the front roller, it only had about five pound of tongue weight afterwards. I raised my bunks (more so in the back) and that allowed the boat to slide about an inch forward and leveled the boat to where there was no downward pressure when winching the boat. Still not enough tongue weight but better than before.
Boatmate's trailers flex too much for me, even with tandem axles underneath (my trailer was tandem btw). They need to stop their production for a minute to do a little engineering IMO.
We've all seen the little exercise with the model car and trailer on a conveyor that shows the importance of tongue weight and myself, I've owned a lot of trailers and hauled a lot of heavy equipment over the years and proper weight placement of the load is extremely important to your safety. I don't believe Boatmate has ever exercised actual testing when they produce any trailer for differing boat models or I would not have had the issues I had recently. Someone proves their accident was a result of the trailer manufacturer's neglect, it would be the end of them. Worse, it gets someone injured.

Tow an RV so I appreciate the importance of tongue weight....even with the GS at the stop I only had 150#'s of TW.
Tractor wheel weight under the spare solved the problem.

The only time I tighten down is when under way, all straps loose when stationary.

 

[GotMyAlly]

They need to stop their production for a minute to do a little engineering IMO.
We've all seen the little exercise with the model car and trailer on a conveyor that shows the importance of tongue weight and myself, I've owned a lot of trailers and hauled a lot of heavy equipment over the years and proper weight placement of the load is extremely important to your safety. I don't believe Boatmate has ever exercised actual testing when they produce any trailer for differing boat models or I would not have had the issues I had recently. Someone proves their accident was a result of the trailer manufacturer's neglect, it would be the end of them. Worse, it gets someone injured.

That is the problem, the trailer company is not engineering the trailer for the boat. But it is not because of neglect or oversight. Darris builds the spec, and tells Boatmate to build the trailers exactly like that one. If the trailers vary from that spec any at all, Darris rejects them. Boatmate isn't given the opportunity engineer anything, just build according to a template. Believe me, I've talked to Boatmate at length several times, and I think they would build the trailers much differently if they were given the opportunity to do so.

To my knowledge, that initial mock-up that Darris builds, which becomes the template for all other trailers, is built using an unloaded boat with no power. And the clearances do not allow for wood shrinkage, carpet compaction, etc.

I believe Boatmate is in a catch 22. Build what their customer (Allison) wants, and they get a black eye because the end user has a bad experience (like my gelcoat damage). Or set the bunks up right for the end user, and their customer (again, Allison) returns the trailer because it is not built to spec.

Trust me, I'm not trying to defend Boatmate in any way. After four Allisons, I've had a couple of trailer issues which were legitimately Boatmate issues. In both cases, Boatmate owned up to it and worked with me to make it right. But on the boat/trailer fitment, I believe that falls square on the shoulders of Allison.

 

[CarolinaBurt]

I wanted to ask if this what most of you see as a problem with fit at the bow. Please keep in mind that I have less than 100 lbs tongue weight and my boat is well supported at the rear (both photos taken this morning). I'm showing this and asking if there is another bow roller/bumper option that can support my bow yet not torque/bend the trailer doing so.

As in the photo, I leave the strap unlatched at the winch and add some tension during hook-up. If I pull the bow to the stop, the strap has to go around the roller effecting a robust "downward" pull. If I load the boat further onto the trailer, then the vertical distance of the bow stop to eye gets even greater and the strap's pull is straight down. This should not be on every boat/trailer. Gordon

 

[GotMyAlly]

That looks like it could make loading difficult on an excessively steep ramp.

I wonder if raising the rear of the bunks a little would push the nose down into the stopper as intended?

 

[scj]

Axle location and flexibility of the trailer is not Darris's call. Cross member design at the rear for boat height and bunk location I agree but the other two are issues with not having enough strength and engineering built into the trailer design.
I could stand on the side rail of a single axle XR trailer and flex it 10". That's no where near enough bridging between the axle to the tongue. They can lay blame wherever but they have the responsibility to produce a safe trailer. Since Boatmate cannot even get the fenders over the center of the tires correct on their trailers, maybe having adjustable axles and fenders would allow a decent looking, functional set up.

 

[FloridaGS]

Gordon, I did look at taking the route of a larger front roller (yes I have the same issue you pictured), and could not find a roller alternative. After taking measurement on the gap, I noticed that the mounting tab were bowed out...so I concluded the trailer must have had a black rubber v bumper...which would be taller and may close the gap. From experience the black v bow bumpers can get destroyed with one hit...so I think the roller is not the original design or intent. Look closely at the roller, mine is so jammed into the bowing tab it barely moves. I gave up on the issue...but you got that bug in my head again..lol..also the pull down of the winch is not optimum...but to address the gap, extending the tab is my thought, if relocation of the roller is not done...

 

[CarolinaBurt]

If you find something that works, please share and I'll do the same. I bought this boat and trailer brand new, so the roller you see pictured is exactly what came from the factory. My boat's bow/eye has never fit the trailer bow stop. I never saw it without it's motor attached, so like SCJ stated - it could be poor mating of trailer and boat - since our boats all need power added to the tail. Mine is one of the lightweight 375 lbs SS models, I can't imagine what a 450 pounder on a jackplate would do...

Thanks, Gordon

 

[Mrbuck50]

CarolinaBurt........I have a 1988 XTB on an SMP trailer and I have the exact same issue that you show in your picture above. I wish there were a better way, but not without heavy modification to the trailer.

 

[Mav73]

My bow eye was 3.5 inches above my roller. I spaced the back of the vertical e bunks up 1 inch. This brought the bow down closer to the roller and raised the boat off of the bottom rollers and the horizontal boards. Then I cut the bow roller off and extended it 1.5 inches. The trailer now fits my boat.

 

[FloridaGS]

That is the fix for sure. Did you block the roller up with a bar of steel?

Also Gordon, although it may have come from the factory with the round roller, I reviewed the v bow bumpers again last night, and it does look like the initial design was for those...one of them would close the gap, but again the black ones break with just one strike and the clear ones cost quite a bit more...I may buy a black one (6$) to test and take a photo.

Also if I do the wxtend route, since I am only gapping 1.5 to 2 inches, I am not messing with the bunks...so much for leaving this be..lol

 

[CarolinaBurt]

The problem I have with moving the rear bunks up on the trailer is that all 4 of them appear to fit the hull and trailer perfectly. When I launch the boat, I look at my bunk's carpet condition, check for loose bolts, and tap on the bunks for general health. All of the carpet is evenly compressed and I'm always happy with the consistency of how the fit/wear looks on the trailer. Both of the vertical bunks supporting the surfaces nearest the pad/keel ride and are supported by the trailer channel (see photo). The two horizontal bunks also rest on and are supported by fixed brackets that do appear to support the sides perfectly. I can't see giving up that seemingly perfect support of the pad, keel, and chines just for the Bow Stop's failure to fit the bow of the boat.

I want to focus on the Bow Stop and fix that - This is where I find my Boatmate trailer falling way short of what it should be. Gordon

 

[GotMyAlly]

Axle location and flexibility of the trailer is not Darris's call. Cross member design at the rear for boat height and bunk location I agree but the other two are issues with not having enough strength and engineering built into the trailer design.
I could stand on the side rail of a single axle XR trailer and flex it 10". That's no where near enough bridging between the axle to the tongue. They can lay blame wherever but they have the responsibility to produce a safe trailer. Since Boatmate cannot even get the fenders over the center of the tires correct on their trailers, maybe having adjustable axles and fenders would allow a decent looking, functional set up.

Agreed....if you've got 10" of flex in the side rails, you've got a dangerous situation (unless you weigh 700 lbs). That doesn't sound road-worthy.

 

[GotMyAlly]

The two horizontal bunks also rest on and are supported by fixed brackets that do appear to support the sides perfectly. I can't see giving up that seemingly perfect support of the pad, keel, and chines just for the Bow Stop's failure to fit the bow of the boat.

The horizontal bunks are only supposed to be guides. Should be able to slide a sheet of paper between the bunk and the hull at the front, and a small gap is acceptable at the rear (1/4" to 3/8").

 

[Mav73]

That is the fix for sure. Did you block the roller up with a bar of steel?

Also Gordon, although it may have come from the factory with the round roller, I reviewed the v bow bumpers again last night, and it does look like the initial design was for those...one of them would close the gap, but again the black ones break with just one strike and the clear ones cost quite a bit more...I may buy a black one (6$) to test and take a photo.

Also if I do the wxtend route, since I am only gapping 1.5 to 2 inches, I am not messing with the bunks...so much for leaving this be..lol

With the boat setting on the trailer in the correct position ,I measured roughly from the roller to the eye. Came out to 1.5 inch. Then I cUT the plates that holds the bow roller. I cut some 1/4 bar stock 3.5 inches long, and welded them to the pieces I had cut off. Then I slid them back into the correCT position so the bow wash touching the roller and I welded into place. If you don't have a welder , you can drill 4 holes on each side and bolt it in place.

 

[GotMyAlly]

Speaking of the bow roller......these yellowish/orange polyurethane ones are HARD. I think I'm going to swap mine out for something a little softer. Since mine does rest on the roller a little (probably 50-100 lbs of weight), I think a little cushion there would be good.