trailer advice please

[realslimshady]

Ok, I have acquired a trailer to put my A25 on, I went for it because it has centre rollers and four bunks, so perfect for the round bottom and keel support required.
My question is, the centre rollers are all in line, i.e on the same level, but as far as I can determine with my measuring and looking at the side view in the manual, the aft roller is going to be under the 'dropped' part of the keel, so the question, now I've finally got to it, is can someone give me an idea of how much lower that roller needs to be from the rest? I'm guessing about four inches, but until the boat is hanging on the crane I won't be able to measure it, which will be a bit late...

[NickScheuer]

Rear roller elevation depends on how far forward you position the hull, or in other words, when you quit winching it forward on the ramp. For many boats you quit winching when the bow reaches the bumper by the winch, however, on my trailer the bumper position is adjustable. I slide the bumper forward while winching, then slide it back to the hull when the trailer is up off the ramp on dry land. The bumper is mounted on a sliding beam.

[motthediesel]

I don't have a 25, but I've fit a lot of boats onto trailers, and with a shapely boat, it is a tricky business. The best way to do it, without doubt, is to have the boat positioned over the trailer, and then adjust the rollers/bunks accordingly.

As you say, the guy running the travel lift or crane is not going to wait a few hours for you to do what needs doing. So -- can you borrow some stands and blocks for a bit? Have the lift operator spot the hull directly over your trailer in the yard, then support it temporarily with stands for the hull and blocks under the keel (where you can fit them between cross members and rollers) -- and then adjust everything to fit snuggly.

At that point, jack the trailer frame up and support it on blocks, if all looks good, pull the stands and keel blocking -- Bob's yer uncle -- remove the trailer blocking and you're all set.

[honza]

IMHO keel rollers (aside from one or two for the very bow) are useless on the 25 because of the big "belly" in the front half of the boat, which has to ride over the stern supports. A simple plank will do the job for supporting the keel. The dropped part of the keel can be left overhanging. Rollers supporting the stern sides help a lot on a flat shallow ramp.

[realslimshady]

I'm not worried about setting it up for launch and recovery. It's going on the trailer for a 1000 mile trip to Portugal where it will, by hook or by crook, be floated off the trailer into the lake, where it will stay. The trailer has a set of centre rollers, just the very aft pair will, I think, be too high. If I could get a picture onto my mac I'd show you...technology....

[realslimshady]

IMG-20201206-WA0000.jpeg[/attachment][/img]trying to load picture

[Burton]

We did this recently. And we did it exactly as motthediesel says above. You say it has two sets of bunks. Well, they’re not going to fit, either. That’s another reason why the stands are critical to start with. The other component that is very critical is tongue weight. If it is too light your trailer will not tow properly and will want to whip back-and-forth. We studied the pictures of a lot of Albin 25’s on their trailers, and hit it very close for tongue weight. Thankfully, we had the boat on stands, and simply worked the trailer underneath it using hydraulic jacks and blocking. It was probably a full day getting it to adjust correctly. If you have only a single roller in each spot, and few crossmembers—we have only four—there’s a good chance the weight of the boat is going to bend the axle down of the roller. I built roller axles out of five eights type 316 stainless steel, and still had one bend when loading the boat. We had to double up on the rollers on each crossmember. Using two hydraulic jacks at a time makes things go faster, as one must keep working around the crossmembers and axles. Go slow and think it out.

[nebulatech]

You may get some ideas from this thread, where members helped me set up my trailer sight unseen. On the first page, DesertAlbin shared a couple of lofting drawings that included stations, which helped me measure out my bunks. The second page has good pics of the rear keel where it drops.
http://www.albinowners.net/aog/viewtopi ... 28&t=12088

I have a picture on my work computer where I did calculations based on hull shape (I know that sounds nebulous) which I will try to post for you later today.

[realslimshady]

You may get some ideas from this thread, where members helped me set up my trailer sight unseen. On the first page, DesertAlbin shared a couple of lofting drawings that included stations, which helped me measure out my bunks. The second page has good pics of the rear keel where it drops.
http://www.albinowners.net/aog/viewtopi ... 28&t=12088

I have a picture on my work computer where I did calculations based on hull shape (I know that sounds nebulous) which I will try to post for you later today.

Thanks for the link. I am sure the rear rollers are too high, so I'm going to remove them, and may even have to cut the crossmember come the time, but I have a plan for that if I do. Slightly concerned about the rollers taking 'all' the weight, but hopefully the bunks (removed in my photo but they'll be there) will be adjusted up to lend some support. Time will tell!

[motthediesel]

If, as you say, this is to be a one-time only use for this trailer, you might be better off substituting a keel bunk board for the rollers. I don't want to start a debate between the roller/bunk fans, but there is no doubt that bunks support the load of the boat more evenly. Admittedly, rollers reduce the effort required to pull/push the boat on/off, but that should not be a high priority for your type of use.

If you do go that way, you might want to plan on a couple open spaces in the keel bunk, rather than one continuous run. This would allow for jacking under the keel, or the use of lifting straps, if you interrupt the other bunks at the same fore/aft point.

[markdbecker]

Ticaboo's Trailer.JPG

Front View of Ticaboo's Trailer.JPG

[nebulatech]

I looked for the picture, but its actually the first picture in the thread I linked to. FWIW, I didn't modify the spacing of the rear bunks, but I did add a 2x4 on top, on each side. I did find another picture, from when I was researching last year. I don't remember the thread, but it shows measurements for rollers. I can't vouch for its accuracy. Perhaps someone else can?

ShorelanderTrailerSchematic.JPG

One last thing, do you have a bow eye? My boat didn't, and I made it home, but I would have liked one. I currently have an undersized one which I will replace with a larger one in the near future.

[realslimshady]

If, as you say, this is to be a one-time only use for this trailer, you might be better off substituting a keel bunk board for the rollers. I don't want to start a debate between the roller/bunk fans, but there is no doubt that bunks support the load of the boat more evenly. Admittedly, rollers reduce the effort required to pull/push the boat on/off, but that should not be a high priority for your type of use.

If you do go that way, you might want to plan on a couple open spaces in the keel bunk, rather than one continuous run. This would allow for jacking under the keel, or the use of lifting straps, if you interrupt the other bunks at the same fore/aft point.

The trailer has four bunks as well as the centre rollers-as I said, the bunks are removed in the picture. I am pretty happy that the boat will be supported fine on the keel rollers with the bunks adjusted up to support the sides and take some of the weight.
All this discussion seems to have muddied the water around the question-which was, can someone (whose boat is on the trailer at the moment perhaps) tell me how much lower the aft roller/support needs to be than the main keel supports. I've removed the rollers but may have to cut the rearmost crossmember to clear the skeg.

[DesertAlbin736]

The trailer has four bunks as well as the centre rollers-as I said, the bunks are removed in the picture. I am pretty happy that the boat will be supported fine on the keel rollers with the bunks adjusted up to support the sides and take some of the weight.
All this discussion seems to have muddied the water around the question-which was, can someone (whose boat is on the trailer at the moment perhaps) tell me how much lower the aft roller/support needs to be than the main keel supports. I've removed the rollers but may have to cut the rearmost crossmember to clear the skeg.

The boat's weight should be primarily supported by the keel rollers just as it would be if blocked up on the hard. You're likely correct that you'll have to modify the rearmost cross member. Here's what ours looks like.

DSCN3631.JPG

One difference with ours is that all but the first two cross members are slightly V shaped instead of straight line. Also the keel rollers can be adjusted up or down a few inches. Not sure how your bunk supports are designed but ours are adjustable both side to side & vertically. The are attached to the crossmembers via U bolts & there are a pair of set screw bolts to adjust the height of the bunks.

Bunk adjuster.jpg

This helped a few years ago when I had the trailer taken out from under the boat to do a bottom job by lifting the bow with a gantry crane & the stern with a forklift, then dropping the bunks as far as possible, blocking the keel, and placing hull stands under the boat as we pulled the trailer out from under. Getting the boat back on the trailer was the reverse procedure, rolling the trailer back under the boat lowering it onto the keel rollers while still supporting it with crane & forklift then jacking the bunks up to support & level the boat & removing the crane strap & forklift. In such a situation if you had these kind of adjustable bunks you wouldn't have to worry about measurements, just jack the bunks up to fit the hull.

DSCN3611.JPG

DSCN3612.JPG

DSCN3628.JPG

As with any of these photos, click on them for a zoomed in view.

[nebulatech]

All this discussion seems to have muddied the water around the question-which was, can someone (whose boat is on the trailer at the moment perhaps) tell me how much lower the aft roller/support needs to be than the main keel supports. I've removed the rollers but may have to cut the rearmost crossmember to clear the skeg.

OK, I just went out and measured for you. Don't hold me to it, but I measure a difference of about 1.75" to 2". My boat trailer sits on a slight incline, and it's on grass and dirt in my back yard. I previously thought the dip was about 4", but looking at it, 2" seems close to correct. I can't five you a 100% accurate measure because I'm not on a uniform and level surface like concrete.

It's dark out right now. I'll try to remember to take a picture tomorrow with a measuring tape.