Tips on centering boat on the bunks

[mnpracing]

When my boat is loaded on the trailer the bow is slightly off-center on the bow roller, to the port side. The bow is essentially resting on the port side of the center section of the bow roller. Is there a known process to assess which bunk may need to move in order to get the bow to center on the roller? The upright that holds the roller is straight (or appears so based on the naked eye), so I'm assuming one or more of the bunks shifted at some point, somehow. Thanks for any suggestions.

[sandm]

high on the opposite side?

not real sure, but I'd put a straightedge on the upright first, then start inspecting the bunks looking for drooping on the side it's leaning on, and possibly high on the other side..

[mnpracing]

high on the opposite side?

not real sure, but I'd put a straightedge on the upright first, then start inspecting the bunks looking for drooping on the side it's leaning on, and possibly high on the other side..

It appears to be sitting level based on measuring each side from the rubrail to a level sitting on the frame rail, so I'm thinking the boat is angled slightly on the trailer. I'll stare at it more tonight and take some measurements.

[mmandley]

Mine sits lightly to the port side as well, always has. I had the dealer shim and measure my bunks. Shimmer the front bunks 1/2 inch and this helped as my nose was always hitting my roller. Boat still comes up slightly to the right when standing in front of it.

I'm going to look at reaimng the winch.

[KT Mobius]

my does as well, but has never been a problem

[mnpracing]

I'm going to look at reaimng the winch.

Mmandley, can you clarify your last sentence regarding the winch?

[kaneboats]

I think he means making sure the winch and winch stand are square with the trailer bunks. RE-AIM-ING it so it lines up. Right?

[mmandley]

I think he means making sure the winch and winch stand are square with the trailer bunks. RE-AIM-ING it so it lines up. Right?

Yes exactly

[mnpracing]

Well, I found the solution to this...I moved the spare tire and carrier to the port side of the trailer. Apparently the spare tire is enough weight to flex the trailer enough to where the bow roller is no longer centered. Now that I moved it, the bow is centered on the roller. I'll check it after a few outings to see if it starts to pull to the port side...

I also notice that when the trailer is supported by just the jack, the roller tweaks to the starboard side making the bow look off-center. I normally have the tongue supported by a jack stand so I hadn't noticed this before.

I wouldn't have thought that there was that much flex in the trailer, but apparently there is....

[moombadaze]

mn, do you have a single axle trailer? thinking the trailer frame is longer between the hitch and axle mounts to allow just a little more flex. I know Mikes is a double axle so this thought may not be allways true

Cant say I have a issue with mine

[mnpracing]

mn, do you have a single axle trailer? thinking the trailer frame is longer between the hitch and axle mounts to allow just a little more flex. I know Mikes is a double axle so this thought may not be allways true

Cant say I have a issue with mine

Mine is a double axle. I was playing around with it and first noticed the flex when I used the trailer jack (port side). So I used a floor jack on the starboard side and noted that the roller centered on the bow with no that much pressure on the floor jack. So I started by taking the spare off the starboard side, which corrected about half the issue. Now that I've mounted the spare on the port side it's centered. So I'll see what happens after a few tows with it like this. I suspect that it may flex the other way, but who knows. Either way seems like a BS way to jimmy-rig these trailers. The last time my dad was down, I had him inspect the trailer for structural issues. He's a welder with a lot of experience building truck beds from the frame up, and custom trailer setups for hauling rigs for the oilfield industry. Any way, he said "besides the light axles, lack of support beams, and thin-gauge steel throughout (he especially noted the the winch tower and bunk support brackets, but said that the rails should have been thicker or reinforced more), it's fine". Not exactly a ringing endorsement....

To clarify, my dad's comments were based on hauling a 4,000lb load (boat + fuel + gear).