Need to increase tongue weight- shift axle, or winch post?

[mfelthousen]

I have a new (to me) boat and trailer, and the tongue weight is too low. If I am not careful while it is unhitched it does not take much to get it to tilt back on the stern drive, so I usually keep jack stands under the rear of the trailer. The previous owner towed with a minivan, so I think they overcompensated on the weight distribution. When I tow with my Grand Cherokee there is a slight tendency to wag under deceleration.

My question is whether it is preferable to shift the axle rearwards, or the winch post forward? I have room to do either with this trailer and boat combination. I know that shifting the axle back changes maneuverability. I'm wondering also if the bunks are going to have to be lengthened if I shift the boat forward.

This is an 18' Starcraft Holiday I/O, so this is an aluminum boat with a rear mounted fuel tank and battery.

Thanks, Mat

 

[ahicks]

My focus would be about maintaining support under the transom as far as placement of the boat on the trailer. Looking at the pic, it looks like you could move the winch stand forward pretty easily. In my mind, it would be nice to have the rear bunk upright directly under the transom. That should increase the tongue weight enough where you'll surely notice the difference.

 

[H20Rat]

Looking at the pic, I'd absolutely move the winch forward. Easier, and it looks like you have room to play with. I'd start with about 3 or 4 inches and weigh it there.

 

[Sea Rider]

The rear wooden bunks seems fixed, welded to lateral frame, right ? is it possible to move the axle along leaf springs at least 2"-3" aft to gain added weight on tongue or is welded to frame ?

If moving the whole winch frame forwards, boat's bow will have nothing to rest on and boat will slide forward if towing vehicle has a sudden stop, say a nerd crossing the street while texting with his cellphone LOL!!

Happy Boating

 

[211libwtfo]

The boats bow will still go in the bow holder on the winch frame. Just move the whole winch assembly.

 

[Alumarine]

If you move the winch stand forward a bit you won't have to lengthen the bunks.
Just move the bunks forward the same amount.
You don't want the end of the bunks protruding past the transom in case they get in the way of a transducer.

Don't bother moving the bunks until you're happy with the tongue weight. You should have about 200 lbs on it if not a bit more.

 

[roscoe]

Move winch forward until boat sits even with back of trailer, align so stern straps go straight down.

Then move axle back to get desired tongue weight.

 

[Bob_VT]

Are there holes pre drilled in the trailer?? As per the photo it appears so. I would honestly consider moving the real axle instead of moving the winch post too close and crowding your tow vehicle.

If you move the axle you will be able to back up easier too. The further back the axle the easier to back up and turn (better control)

 

[M2HB]

Are there holes pre drilled in the trailer?? As per the photo it appears so. I would honestly consider moving the real axle instead of moving the winch post too close and crowding your tow vehicle.

If you move the axle you will be able to back up easier too. The further back the axle the easier to back up and turn (better control)

That is what I would do.

Others have mentioned moving the boat forward. It can be moved slightly, but it can't go even with the back of the trailer because the rear keel roller hangs off the rear crossmember. The transom needs to at least be on the rear keel roller.

 

[Alumarine]

That is what I would do.

Others have mentioned moving the boat forward. It can be moved slightly, but it can't go even with the back of the trailer because the rear keel roller hangs off the rear crossmember. The transom needs to at least be on the rear keel roller.

Why does the keel have to be on the rear keel roller?
is the weight not supported by the bunks?

 

[ahicks]

It's not like this boat would need to be moved a whole lot to make a difference. Sure moving the axle would do the job. My thought though, is that moving the winch stand would be much easier. If it takes so much that it's going to be crowding the tow vehicle (doubtful in my experience) THEN it's time to drag out the axle move option. Existing holes no big deal. It's not that hard to drill them where you need them.

Further, I would think the more support the better. If I could get the keel roller AND the bunks to all help support the weight of the transom equally, that would be the ideal/perfect scenario.

 

[mfelthousen]

Thank you everyone. The trailer has additional holes for shifting the axle, and based on the paint it has been moved in the past. It looks like I could make the trailer a tandem, if I really wanted to.

The winch post is also adjustable, as it is held in place with large U-bolts, although I'll plan to find replacements first in case these are frozen. The support posts for the bunks bolt on, and there are extra holes to adjust their height, angle, and placement. There is another stringer in the trailer ahead of the axle that is pre-drilled for the bunk supports, (lines up with that orange reflector) but the three stringers ahead of the axle only have center rollers at the moment. Most of the rollers are height adjustable too. It looks like the only roller that is supporting weight to any degree is the front roller. Otherwise the way the bunks are adjusted the center ridge just rests in the guides of the rollers.

I do have plenty of room until I'd have an issue with tow vehicle interference. I hesitated to move the winch, even though it seemed easiest, because the bunks seem short compared to the boat (less than half the length). Right now the transom lines up with the rear edge of the bunk, but the bunks overhang the back of the trailer by nearly a foot. The transponder and speed pickup are both outside the path of the bunks.

I've been thinking that shifting the winch forward would also mean shifting the bunks forward a corresponding amount. Or, since I don't know the age of the wood, replacing them with longer bunks that are also shifted forward. I know I can get support posts for the bunks that are identical to what I have now.

This is all helpful-
Mat

 

[ahicks]

This is not a real heavy boat. No need to overthink this. The bunks hanging out in back of the boat aren't going to hurt a thing. If they make your eyes hurt when looking at them, unbolt the wooden part and relocate it a little further ahead.

From what you've said about the rollers, it sounds like they need to be adjusted. In a perfect world, all of the rollers would be helping to support the boat - no free rides! This helps spread the load out to minimize flexing of the hull going down the road - a good thing considering longevity. It also helps prevent trailer frame flex. With an equal load on all the support points, everything is going down the road as a single unit.

 

[Sea Rider]

Next time combo is on water, unbolt both sides and move the whole axis backwards some inches till desired tongue weight is reached and voilá.. It's the simpliest form and should be the fastest one to go for.

Happy Boating

 

[M2HB]

Why does the keel have to be on the rear keel roller?
is the weight not supported by the bunks?

The Keel is usually one of the strongest parts of the boat. It should be supported by a keel roller, if you have keel rollers.
I adjust my aluminum boat so that the keel rollers take at least half the weight. Why leave a rear keel roller unused for support? That is what would happen if this particular boat is adjusted to where the rear of the transom is flush with the rear of the trailer.

 

[Sea Rider]

The whole hull should be supported evenly by side bunks and central rollers as well. The mission of the central rollers is to make it easier for central V hull to roll on while lateral hull slides much easier on top bulks when combo is winched out of water.

Happy Boating

 

[Woodonglass]

Absolutely ALL that is required to move the winch post forward until the back of the trailer is even with the back of the boat. Your tongue weight will be increased and all will be fine.

 

[jimmbo]

Move the axle back, or make the wife and mother in law ride in the bow of the boat(under the tarp of course) while towing

 

[mfelthousen]

Thanks everyone. I was able to get the weight from 5 pounds to 75 by shifting the winch post forward. But, that was before I put gear back in it (still redoing floors, seats, etc). The edge of the transom is right on the center of the rear roller, so I know my next step is to move the axle, after I get a few other things worked out.

Mat

 

[ahicks]

Perfect! Great plan.