trailer bunks loose or tight?

If the boat isnt perfectly square when loading, at least one bunk will shift 90º (so the boat rests on the narrow edge) despite the bolts being as tight as I can get them. I didn't catch that it had flipped in march and i didn't have tools to fix it yesterday. So should the bunks be loose enough that they move freely as the boat is loading, or should they be tightened in the orientation they would rest with the boat loaded?    If they should be tightened, is there anything I can do to help prevent them from flipping (other than loading the boat square ) I don't have a pic of the bunk flipped, but here is one with them tightened in the correct orientation.

quinner wrote: BTW, Hollywood rides the same bike as yours

Chris, close, but not the same. IIRC, Kevin's bike has handlebar streamers on it.

scootdogydog wrote: quinner wrote: BTW, Hollywood rides the same bike as yours Chris, close, but not the same. IIRC, Kevin's bike has handlebar streamers on it.

Hollywood wrote: and quinner has the same pool

It sure sounds like you two have plenty of fun together on play days!

And that's Zach's luggage on the back end before he landed the sweet job with The Cat Dealer.

Might be a balance issue if they are inclined to flip the wrong direction. I'd shift the bunk so that it always fell in the right direction if you were set on leaving them loose. Or lock them down in the position where they support the hull?

What year boat? What model trailer? Looks like a flat bottom (SN)? Normal (non-delux) #3's didn't get those inner helper bunks until much, much later (early 00's). #4-dv's got them around '80-81.

TRBenj wrote: Or lock them down in the position where they support the hull?

'89 sport nautique. not sure what model trailer it is. the 89 SpN was a mid-year production boat, so the brochure doesn't show this particular boat, and they did change a couple things for '90 SpN. The trailer is not the same as in the '89 brochure and the '90 brochure does not have trailer pictures. I'm assuming this was the original trailer as it does have a Sport Nautique decal on it.

I've been trying to tighten them the best i can, all the other bunks are tight and not shifting, just the rear port side one. Since our water is pretty muddy, it's hard to see the point in time when/where the bunk will flip. The boat has to be flipping it as they won't budge with my scrawny arms and I doubt the calm water is flipping them. The helm is starboard, i can't see (or feel) an imbalance to the port side. If i do leave them loose (which we tried when we redid the bunks in 2014), they tended to be "floppy" in the opposite direction of the picture (they would flip inward, not outward) with the boat again resting on the narrow edge of the bunk so that is when we tightened them all down. When loading the boat, I don't notice any change either. Usually very smooth loading. So not like there is a hard "hit" or sudden shift.

Thinking about this, The angle bracket that connects the bunk the the trailer is wider than the trailer upright, so I could weld some steel that would "box in" the upright so it would prevent the bracket from rotating yet leaving the bracket still easily removable. hmmmm

TRBenj wrote: Might be a balance issue if they are inclined to flip the wrong direction. I'd shift the bunk so that it always fell in the right direction if you were set on leaving them loose. Or lock them down in the position where they support the hull?

+1 if it flips the wrong way, I bet the bunk as re-installed in the wrong direction, or not using the correct bolt placement, etc.... They should lock down in place....

You could also drill a hole in the bunk L bracket and put a bolt through to "pin" it from flopping out of place.. .

Going deeper with the trailer will make the problem worse, you should go shallower.

Hollywood wrote: You could also drill a hole in the bunk L bracket and put a bolt through to "pin" it from flopping out of place.. . Going deeper with the trailer will make the problem worse, you should go shallower.

The pin was one of my original ideas, so I haven't completely ruled that out, just didn't want to drill through the bracket...sounds like i'd get metal in my eye. I think my options pretty much are to keep the bracket from rotating by:
1. U-bolt with plate
2. Pin through the outboard side of the bunk bracket. Should the pin go through the bracket and the c channel?
3. horizontal steel plate "shelf" welded to the outboard C channel upright preventing the bracket from rotating
4. vertical steel plate welded to the outboard bracket boxing in the C channel.

from our experience, if we go shallower, it seems like it needs a lot of power loading to get it to the front of the trailer. with the fenders just barely covered, it still requires some power, but i don't have to "gun it". I will play with trailer depth sunday if the ramp isn't too busy.

Or mask and snorkel

Have you tried removing the bunk, rotating 180 deg and reinstalling?? If that is an angle and the top leg is above the C-Channel that may prevent it from rotating

Assuming you centered the angle bracket on the wood bunk? If so, you've got a 50/50 shot of it rotating out once it comes level (which may be happening when they float).   Move the wood bunk an inch to the outside and it'll increase your chances of it falling inwards. I would do this for both bunks. Pin it to prevent outwards rotation if you want belt and suspenders.

I think you have it backwards.

My post was poorly worded, but you interpreted opposite.

Move the angle bracket outwards on the wood bunk. This will allow more bunk to overhang inwards. This inwards weight bias should make it prone to rotating that way.

So after looking at that bunk with the boat off yesterday, I have determined that when I attached the angle brackets to the wood, i must have made the brackets 1/8-1/4" closer together. The front bracket was tight up against the c-channel and the aft bracket had just a tiny bit of space to it which i am guessing kept the two parts from really tightening down on each other. So we used the winch to slowly load the trailer and kept watch on that particular bunk. It is now laying correctly and I will fix it with a second bolt tonight.

Thanks again for everyone's input and I'll be glad not to worry about it anymore