Trailer refit ballance question

[billh]

Thanks all for the forum, this is an invaluable resource. With that being said and all the assis from Trinka, and others, the trailer refit is going well.

However I am not an engineer by trade and tend to just do things "good enough". But, I am at the point with the trailer where I need to set the risers to the hull.

By what I can understand the mass weight is on the keel. I have the keel well centered with minimal tongue weight, and well centered over the axles. I do not as yet know the actual weight on the tongue but will see how to go about measuring that soon.

Meantime, I am ready to place the rollers that steady the hull. I understand that they obviously keep the boat from falling off, as well as hold a certain amount of weight maybe 10% of the boats weight?

As I am using some legs and ubolting those on, I am able to move them thus gaining some adjustment. So, what I am concerned about is balance. What might be the best means to measure so that all four legs are well balanced? I have two for the rear and two for the front. I am using four large roller racks mounted on top of a post.

The question becomes, where is the best placement and how do I ensure that there are equal? My thought was to simply meansure off the main frame of the trailer, create some marks on the hull of the boat and try to square up to those marks. Maybe I am just over thinking this.

I would like to be sure I have equal pressure on the legs, not more lean to the starboard or port side while she sits on the trailer so to speak. I would like to be confident while traveling that more weight isn't on one side creating a problem.

Feel free to ask questions if I am not clear here, not sure I am saying what my intention is clearly.

You can see some pics here I will try to get more detailed ones up this week though of the legs and roller assemblies.

https://plus.google.com/photos/110614530504099225573/albums/5692734272815617041

Thanks again.

Bill H.

 

[Joe11688]

Bill,
In the pics of my trailer's extension brackets that hold my bunks, you'll notice that these brackets are bolted to my trailer's cross members and when the bolts are loose, the brackets can slide up or down very easy.
I was able to stick a mechanical car jack under each of the middle brackets on both sides of the trailer and jack up the bunks so that they would support the hull on each side with most of the weight of the boat on the trailer's keel board. I then took a measurement of each bracket to make sure that they were even.
You're going to have to do something very similar to your trailer but like I mentioned previously, you'll need to get the proper tongue weight before you go too much further.
What I did was get my bunks to support the boat as mentioned and I used a bathroom scale to get the tongue weight. To do this, I needed to get the boat and trailer on level ground, chock the wheels and disconnect the trailer from the tow vehicle. I raised the tongue of the trailer so that it was level with the ground, and I took some blocks and put them under the coupler with the scale on top.
Experts tell us that between 5% to 10% of the total weight of your loaded trailer should be felt on the trailer's coupling ball when the trailer's tongue is parallel to the ground. For example, if the gross weight of the trailer and loaded gear is 2000 lbs, the tongue weight shouldn't be more than 200 lbs or less than 100 lbs.
I took this out of "Handbook of Trailer Sailing" by Robert F. Burgess so use your own discretion and find out more about this as it applies to your rig.

I checked the weight on my trailer tongue and it was too tongue heavy so I connected the trailer and backed the boat and trailer down the ramp to let the boat float back a few inches. I have two centering guides on the back of my trailer and I was able to put a pencil mark on my hull and use one of the guides as a reference point.
When I weighed the tongue again I came up with about 211 lbs which is right in the ball park for my rig.
After that I was able to use the jacks to adjust the two fronts and two rear extension brackets and taking measurements between the top of the trailer's cross member and the under side of the cloth bunk.
The last task was to move the winch stanchion so that the bow was up against the roller on the stanchion. Actually I had to remove the stanchion and mount on the tongue inside the trailer's ''A" frame. It's an odd place to put it but that's where it needed to be because my trailer was built for a 23' boat. My boat is a little less than 22' long.
It took me less than one hour to adjust my trailer with the boat on it. I had my four boat stands and two mechanical jacks with me at the club.

You'll need to adjust your rollers so that the hull will be supported without rocking from side to side with most of the boat's weight on the keel rollers.
I hope that I was able to be of some help here. If you have any questions just fire away.
Joe

 

[Scott On Eagles Wings]

I agree with everything Trinkka just said, I would just add the following comment. Tongue weight is very important if you are towing at or near your vehicles towing capacity. Too much and it affects the way your front end stays to the ground during turns and wind blows. Too little and it will lift your tail end off the ground, just look at a "pit manover" too little tongue weight acomplishes the same thing.

Adjusting our stabilizing rollers will simply be trial and error. I have had my boat for 7 seasons and about 30 launches and retreivals in that time and could not say with any certainty that it has ever been on the trailer the same way twice. The stabilzing rollers should guide the boat toward the center.

The last thing I will comment on is becuase I sometimes have difficulty bringing the boat fully forward on the trailer (may be bace 3 or 4 inches back) depending on the ramp I am using, I have about 20% tongue weight to be on the safe side. Also mentinoning this I tow 4,500 lb (boat & trailer combined weight) with a 12,000lb capacity vehicle. I have a tremendous safety factor built in.

Our first few launches and espeically retreivals were quite the specticle at the ramp until we got our trailer adjusted right. I am afraid i know of no short cuts to share with you through the expereince. Enjoy your boat, you will get it. Scott "On Eagles Wings"

 

[kdssail]

pictures of odays on roller trailers

here are a couple of JPG's I had that if you enlarge you may see some facts your are looking for on the roller positions.
Dave KDSSAIL@HOTMAIL.COM