Converting roller trailer to bunks, looking for advice.

nurseman

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I am a first time boat owner, and am doing a full rebuild of my boat. While I am at it, I thought I would redo the trailer as well. I want to convert to bunks rather than the rollers that are currently on there. Here are some pics of the trailer as it sits now





Here are a couple that show the boat on the trailer







I am thinking that I will need to add another cross-member in front of the axle to support the front of the bunks, but I would love to hear any suggestions from those who have more experience with boats and trailers.
 

nurseman

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I am thinking that the forward cross-member would go about where the piece of plywood is sitting. I was planning on making it the same shape as the member at the rear of the trailer.





Looking forward to any comments!
 

alldodge

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Use to have a 1966 Signa tri-hull and it was a bit heavier then yours, but took a bit to get it straight to get it on. I like bunk trailers, but putting one setup to load a tri-hull will take some doing. Your going to need a deeper V setup in front, then tapper back toward the rear. You cross beams will need rollers in the center to protect the keel when it is going on the trailer. Don't have a better pic right now, but in the one below you can see the cross member and the roller in the center.
Formula 2013.jpg

The beams under the hull will need to be bowed in the center. The rear ones will need to have steel angles on them and be able to pivot so the 2x6 boards will flatten out on the hull. Something like this

5196_st.jpg


Might be easier to get another trailer
 

airshot

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I currently own my first all roller trailer, was not sure how I would like it as I was used to bunk trailers. After 4 years of roller trailer use I would not go back to a bunk trailer. You may very well just add another set of rollers farther forward and these will help to align the boat on retrieve. Getting them adjusted to fit the hull is the only trick but once done it is much easier to load and launch. Just wondering what your trailer capacity is? As I am looking at your pics the boat appears to be a bit to big for the trailer, mabey an optical illusion but in all the pics it appears you may want to consider a bigger trailer. Just my two cents worth.........
 

gm280

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Looking at your present setup, you are going to have to do a lot of work to change it over. For certain at the very least another cross-over beam and I would install a few if it were mine. It looks like the trailer is really a little short in length as well in my opinion. You have zero room to slide the boat on where the transom area of the boat is actually lined up with the end of the trailer to use tie downs correctly without rubbing on the boat itself... And the actual width is suspect as well. The wheels/tires are of the smaller type and under the boat rather then aside of the boat. Is that the original boat trailer setup or has it been changed somewhere down the line? If it were mine and I couldn't find another trailer closer suited to the boat, then I would be some serious work on it to fit the trailer to that boat. JMHO!
 

Bondo

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Ayuh,.... That wagon looks W aa yyy to small for that hull,....
 

alldodge

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Not knowing the exact year (late 60 early 70), I think the boat only weights around 1300 to 1400 including motor
 

smokeonthewater

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This question gets asked a lot... The BEST advice here (and rarely taken well) is STOP... don't do it.... First as others have mentioned that isn't enough trailer for that boat... that's a 1000 or 1500 lb axle and with the all up weight of the boat, batt, motor, fuel, trailer, and gear, you are in the 2000 lb range.. the trailer is narrow and carries the boat high IE top heavy... It isn't really long enough either....

Next converting roller to bunk or bunk to roller is ALMOST never economical or otherwise ideal... You can almost always simply buy what you want and sell what you have and end up with less money spend AND a much better result.... If you are like me and really scour craig's list you can end up with a free trailer and cash in your pocket.

Last. Why do you want to convert... Not always but quite often people simply aren't using their trailer correctly and think the other design is better because they simply don't know they are dong it wrong.
 

JimS123

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Awesome trailer. I have one similar to it, but by a different manufacturer. Replace the rollers and bushings (if needed) and give her a good paint job. It looks like your setup is pretty good - I imagine she launches like a dream. Put bunks on and you'll be sorry because your launching experience will be awful.

Do check the capacity plate and weigh the rig to be sure the load is not too much.
 

redneck joe

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i'm in the get a bigger trailer camp. No preference rollers to bunks but bigger is needed unless you are using it from the marina parking lot to the marina ramp.
 

nurseman

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Thanks everyone for the input! I have suspected that the trailer was somewhat too small, but wasn't sure. Like I mentioned at the top, this is my first boat, and this is the trailer that was under the boat. On the plus side, it was free to me. The hull is an 83, and the Lund catalog states that the hull is approx 850lb, plus motor.
 

airshot

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OK that 850 is a bare hull, add motor,add 75 lbs for 1 battery then add another 125 lb for fuel or more, then safety gear, then fishing gear, then accessories you will be past 2000lb before you know it. I would be surprised if that trailer had a 2000lb capacity and if it does you are at max. Also looking at the length, it looks short which can be more difficult to backup, and it also looks narrow which makes the boat set much higher and more of a challenge to launch and load. Just something to think about !!
 

smokeonthewater

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and don't forget the weight of the trailer itself.... most of the bigger truck stops have cat scales and can weigh your boat for about $9
many scrap yards, co-op's, garbage dumps, etc will weigh you for cheap or free.
 

TD_Maker

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The trailer does look a little small, but..........

Converting from my all roller trailer to a bunk trailer was the best thing I ever done. Roller trailers here in Florida are a nightmare....RUST RUST RUST RUST play havoc on the roller wheels...Did I mention rust? I simply cut off my roller wheel trees, and used the same uprights for the 2 x 6 Pressure Treated bunks. I think I converted the trailer completely for about $100. Now I load and unload easily, and I no longer have to worry about wheels breaking off as I trailer the boat down bumpy roads. I just have to be aware of shallow gradual grade ramps in some areas.

I will see if I can get some pics for you to see. Posting pics on IBoats has been a little different lately.
 

bonz_d

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Since 2cents isn't worth much theses days, here's mine. Many seem to think that trailer looks too small and I disagree with that but not the fact that it's too small for the weight.

Let's take a look back at how trailers were designed and built 55 years ago. here is one example.



They were All pretty much built this way. Bunks and rollers together. Narrow and very high with small wheels. Since then design thought has changed. Trailers have become wider and lower. The trailer in the picture had a Lund on it that was so high I could travel with the engine in the down position and still have 12" of clearance between the skeg and the ground.

I'm not going to argue the bunk or roller thing because that is no more than a personal choice. I have owned and used both. But I will ad this to that Dilly you have. It appears to me that this trailer was originally built to be a tilt bed and someone has welded it closed. Hence that chain you still see hanging at the front of the bed.
 

alldodge

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IMO It looks small only because of the appearance the trailer does not go to the stern in the pic. As you know it does because the roller end is back there, and the trailer is plenty for the boat. My Signa trailer tilted and I tried it a couple times, but turned out more trouble then it was worth. Probably be good with a shallow launch area.
 

gm280

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AllDodge, I honest respect your opinion and always have, but I have to still say that trailer was never made for that boat! And there is evidence if you take a real good look at it. I see a winch tower assembly that is of different paint as the trailer frame. And the fact that the tire/wheel assemblies are literally under the hall instead of aside of the boat, like most other trailers are setup, with the exception of pontoon trailers. And even IF you could slide the boat forward, the length of the boat exceeds the length of the trailer frame! So I say the trailer is too small for that boat. And the fact that the tires are of the smaller size indicates a light weight trailering ability. I think somebody took that trailer and tried to make it work for that boat and I am really surprised the axle and springs are still holding the weight personally. The springs are rated for X amount of weight but as the trailer hits high and low spots while on the road, that weight increase on those springs and axle assembly. Dry weight is one thing, but dynamic weight changes are certainly a lot more. And the fact that there are zero cross supports is the final evidence. That certainly is no heavy built trailer for that particular boat. Even the rear cross beam that actually hold a majority of the boating weight is merely tack-welded to the side rails going forward. But that is only my uneducated opinion.
 

airshot

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GM280 I have to second your uneducated opinion, Your thinking is with mine so now he has .04 cents of worthless opinions.

Airshot
 

nurseman

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Thanks everyone for the comments! Lots to think about now. Not sure if I will try and make this one bigger, or just shop for a used one that I can just repaint and go. Got a used boat place that has trailers not too far from where I'm at, might see if I can slip over and have a look.
 
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