Adjustment advice (Pictures Inside)

[Behemoth]

Hey all. I am looking for some advice on bunk placement here. This trailer is new to me but appears to be as old as the boat and motor (30ish years) but I do not think this is the original. Since I've launched the boat a couple of times I noticed the bow stop had slipped back a few inches. I recently brought it back forward towards the tongue as it got a nasty vertical bounce. I did not experience this the first time I towed the boat 30 miles from where I got it and chalked it up to the boat falling back several inches with use.

Some thing of concern to me is the bunks. They just don't feel right when launching, loading or just how they look. I want to adjust them. The Red and blue lines indicate what I am hypothesizing as for where to adjust. Any opinions if I am on the right track here? For an additional note I am replacing the 3 rollers on this with auto centering rollers. I already have the 3 replacements and intend to put them on when I adjust the bunks.

Please let me know what you think and if you have questions that I might be able to answer in helping your guidance.

 

[DouglasW]

You will get plenty of advice about the bunks. But I would suggest making sure to use the stern tie downs in any case. I notice you have none.

 

[jimmbo]

That trailer has seen some trauma, The tongue looks twisted, the port wheel looks like the spindle/axle may be bent.
The bunks at the front need to be spread apart a bit, to get them out from under the strakes.
That trailer looks like it is a little light for the boat

How about a picture from the side that shows the entire boat and trailer

 

[MTboatguy]

I am going to agree with Jim, that trailer has been rode hard a bit and the bunks are in the incorrect position and need to move out, if the axle is bent as it looks to be, something needs to be done about that. I would at least check the bearings to make sure something is not going on there.

 

[Scott Danforth]

the trailer looks 2 sizes too small for the boat.

 

[ahicks]

I think getting the bunks located under the strakes is a good plan as well. In a perfect world, your rollers and bunks would both share the load in supporting the hull.

The twist visible at the coupler is evidence the trailer has been jack knifed at some point. It happens... Not too big a deal as long as there's no kinks or other visible damage to the tongue of the trailer - either where the coupler bolts on, or to the rear of that.

 

[jimmbo]

The bunks at the stern look like they are located fine, provided they are between the strakes. Moving them outward towards the chine will only make much harder to center the boat when loading. The bunks do need repositioning up front.

 

[harringtondav]

the trailer looks 2 sizes too small for the boat.

I agree. Check the max. load rating on the tires. Add 500-600# for the trailer to the weight of your boat. 1/2 of that total must be less than the rated tire capacity.

Or tow it to a truck scale and note the weight of both tow vehicle and boat. Drop the boat and weigh the tow vehicle separately. The difference, less tongue weight, is the weight on the trailer tires. Also note the inflation pressure. Trailer tires are not automotive tires. They normally need to be at 50 psi to achieve the rated capacity.

Generally bunks should be halfway between the keel and the chine on each side, slightly favoring the chine side. Your blue looks OK, maybe an inch or so more to center. This evenly distributes the weight, and stabilizes the boat on the trailer. Per Jim, spread the front supports a bit. The transom should have a bunk support under it, no overhang.

 

[Behemoth]

You will get plenty of advice about the bunks. But I would suggest making sure to use the stern tie downs in any case. I notice you have none.

Thanks! I do have tie downs just not on at the time of the image. I had just finished adjusting the winch post and pulling the boat forward. I also tow only 1 block to the main ramp otherwise I do have the stern tie downs.

 

[Behemoth]

That trailer has seen some trauma, The tongue looks twisted, the port wheel looks like the spindle/axle may be bent.
The bunks at the front need to be spread apart a bit, to get them out from under the strakes.
That trailer looks like it is a little light for the boat

How about a picture from the side that shows the entire boat and trailer

I had never noticed it before but now that you mention that does look a bit twisted. It tows true forward but I do have a bit of an extra difficulty backing down. Maybe this is why. I looked up the info on the trailer when I fist got this and the weight of the boat/motor from online. Everything looked to match the trailer ratings and the tires were all new and done with a tire shop that match.

Bearings were recently replaced and repacked. Nothing was bent when replaced where the wheels go. The axle might be a different story.

Let me get some new pictures later

 

[Behemoth]

The bunks at the stern look like they are located fine, provided they are between the strakes. Moving them outward towards the chine will only make much harder to center the boat when loading. The bunks do need repositioning up front.

I am hoping the auto centering rollers would help that

 

[Behemoth]

I agree. Check the max. load rating on the tires. Add 500-600# for the trailer to the weight of your boat. 1/2 of that total must be less than the rated tire capacity.

Or tow it to a truck scale and note the weight of both tow vehicle and boat. Drop the boat and weigh the tow vehicle separately. The difference, less tongue weight, is the weight on the trailer tires. Also note the inflation pressure. Trailer tires are not automotive tires. They normally need to be at 50 psi to achieve the rated capacity.

Generally bunks should be halfway between the keel and the chine on each side, slightly favoring the chine side. Your blue looks OK, maybe an inch or so more to center. This evenly distributes the weight, and stabilizes the boat on the trailer. Per Jim, spread the front supports a bit. The transom should have a bunk support under it, no overhang.

I want to do the truck scale but I don't have anything near here to do that. I have used the info from what I can find online for the hull and in my motor manual to get the weight and it appears to be fine for the trailer weight. I'm a noob when it comes to trailers and I always thought this trailer might be too narrow but I was hoping that getting the bunks and rollers fixed might help that out.

As I replied to someone else, these area new bearings and tires all set up for trailer and the load rating for what the boat should weigh + gear.

I'll probably be giving the bunk adjustment and roller replacement in the next few days.

Thanks for the advice!

 

[jimmbo]

I am hoping the auto centering rollers would help that

Auto Centering Rollers?

The only places I've seen auto center rollers are on trailers like EZLoader

 

[Behemoth]

Auto Centering Rollers?

The only places I've seen auto center rollers are on trailers like EZLoader

Auto center keel rollers to replace my existing keel rollers. They have a groove in them to catch the keel and pull center while winching

 

[jimmbo]

you mean the ones with a spiral groove?

 

[Behemoth]

you mean the ones with a spiral groove?

yes

 

[jimmbo]

I have seen them. I don't think much of them, but... Just make sure you put it on correctly, one guy at the ramp had them, but had them spun around. They wwere always trying to push the keel, usually diagonally off the trailer.

 

[Behemoth]

I have seen them. I don't think much of them, but... Just make sure you put it on correctly, one guy at the ramp had them, but had them spun around. They wwere always trying to push the keel, usually diagonally off the trailer.

Thank you for mentioning that! I do see how they go on. There is a small stamp showing how they install that I found. I also read it somewhere on here. If I do it wrong I should be able to do this at a quiet ramp where I can launch and adjust if I need!

 

[MTboatguy]

I have seen them. I don't think much of them, but... Just make sure you put it on correctly, one guy at the ramp had them, but had them spun around. They wwere always trying to push the keel, usually diagonally off the trailer.

Actually if you use them correctly they work pretty good, several of the boat trailer places around here use them when setting up a trailer, they have made quick attach systems for them, then center the boat with them and then adjust the bunk positions to center them.

 

[Behemoth]

Actually if you use them correctly they work pretty good, several of the boat trailer places around here use them when setting up a trailer, they have made quick attach systems for them, then center the boat with them and then adjust the bunk positions to center them.

That is reassuring. Hopefully today is the day I can get the boat launched and the new rollers on. :thumb: