Trailer balance questimate?

[ryan 98]

So here it is. Just did the boat, jacking plate and motor. With the new setup the trailer is sitting at a total neutral balance. You can set it on the skeg or the tongue and it will stay. Picking up the tongue of the trailer it has absolutely no weight. I got lucky and my dad rented a dock for his boat so I've borrowed his trailer for my boat and I finaly have my trailer free to work on. It's getting all new rollers, paint, bearings and wiring. But my real question is how far to shift everything forward to get a good amount of toung weight without it being to heavy to move. I'm hopping for a good questimate as It's a massive pain to tow it all to a launch and switch them over. Now there are 2 options. 1 is to shift the rollers forward, not too hard to do but I'm limited to shifting every thing only 5 inches before I run out of tongue. Option 2 is to move the axle mount further to the rear. Easy enough also, but I would have to have some custom u bolts bent up for it since the ones on it are not coming off in 1 pice. If there's anyone with a good guess as to how far to move stuff I'd appreciate it. At least i can get it in the ball park. And yes I would need to move the whole rear roller setup forward if I go that way, but I don't see anything preventing me from just drilling and oversized hole and welding a pipe to bolt them to up further. Thanks

 

[ryan 98]

I'm just now noticing the camera on my phone tricks the eye. The boats under 15 feet and there is truly only about 5-6 inches of tongue in front of the front roller mount. Even tho it looks like a good foot in the photo

 

[Harritwo]

Ideally 10 % ±2% of your trailer weight should be on the tongue. For me, the easiest way would be to move the axle back about a foot. You would need to know your motor weight, your hull weight and your gear weight where it is normally stored during towing to work the calcs out.

 

[ryan 98]

Ideally 10 % ±2% of your trailer weight should be on the tongue. For me, the easiest way would be to move the axle back about a foot. You would need to know your motor weight, your hull weight and your gear weight where it is normally stored during towing to work the calcs out.

Tanks are in the back. Nothing else in the boat that would add any considerable weight when towing. Mostly tow it totally empty. I'm guessing around 1k pounds all in when towing. I'd usualy set a trailer up by the 10% rule. But being as light of a package as it is I'd kinda be inclined to go for about 50 or so pounds at the ball so I can drag it around the yard on my own. It's not going to push a tow vehicle around too much as long as the weights at least biased forward. I'm thinking moving the rollers up the 5 inches will get me in the ball park. Just had no idea how much effect it would have per inch. By my eye about 80% of the weight must be behind the axle for it to balance where it does currently.

 

[ryan 98]

Tanks are in the back. Nothing else in the boat that would add any considerable weight when towing. Mostly tow it totally empty. I'm guessing around 1k pounds all in when towing. I'd usualy set a trailer up by the 10% rule. But being as light of a package as it is I'd kinda be inclined to go for about 50 or so pounds at the ball so I can drag it around the yard on my own. It's not going to push a tow vehicle around too much as long as the weights at least biased forward. I'm thinking moving the rollers up the 5 inches will get me in the ball park. Just had no idea how much effect it would have per inch. By my eye about 80% of the weight must be behind the axle for it to balance where it does currently.

Also 1 foot back on the axle would put it with the axle frame at basically the back edge of the trailer. Not picky if it worked but it would be one hell of a goofy looking trailer. Maybe start with the rollers all the way forward and see what I get from there? I guess you could do the math somewhat by dividing roughly 1000 pounds by 2. So 500 per side of the axle. Then work it out by the distance it sticks out from each side of the axle to set it about 100 pound forward biased. Hey... I think I'm on to something there...

 

[roscoe]

The rollers need to stay where they are.
Last roller needs to be under the edge of the transom.
Otherwise you are asking for trouble, like creating a hook in the hull.
Or even cracking it.

Move the axle back a foot.
They sell all kinds of trailer hardware "U" bolts.
No need to fabricate them.

try etrailer or easternmarine web sites.

You might even find them at your local hardware store or farm supply

 

[ahicks]

Set the boat on the trailer where it needs to be to get good support under the transom. THEN put the axle where it needs to be for proper tongue weight with boat loaded as it will be most often when towed.

 

[ryan 98]

The rollers need to stay where they are.
Last roller needs to be under the edge of the transom.
Otherwise you are asking for trouble, like creating a hook in the hull.
Or even cracking it.

Move the axle back a foot.
They sell all kinds of trailer hardware "U" bolts.
No need to fabricate them.

try etrailer or easternmarine web sites.

You might even find them at your local hardware store or farm supply

That's just about what ive come up with. But I will move all the rollers up first. That includes moving the entire roller sets up further and setting them so they hit the back edge of the transom just right. The hull is already badly cupped. I think I even made it worse doing the core while it was on the trailer. They never really sat in the right place to begin with. Then I hopefully won't have to move the axle mount too far back. At 1 foot back that already means I'd be in to the tail lights and brackets with the axle mount. Basically what I'm getting out of all your replies is the boat and axle will need to be shifted about a foot total forward. That's the bit I want sure about. I think all start with the 5 inches forward that I can shift the rollers, then kick the axle back about 6 inches and see how it balances then

 

[H20Rat]

You also want to be careful with too much tongue weight. Many trailer mfg's have a max of 10%, higher than that you could be asking for trouble. (voiding warranty &/or safety issues) Overloading the rear of a tow vehicle will also cause all kinds of fun handling issues.

Lower drag/low center of gravity loads can get by with less tongue weight. If you have something high up (a pontoon), it can actually decrease tongue weight a little while you are pulling.

Just did a quick check of 3 big trailer mfg's and their recommendations.

ezloader-10% max
yacht club - 5-10%
shorelandr- 6% single, 5% tandem, 5-7% allowable range

 

[ryan 98]

You also want to be careful with too much tongue weight. Many trailer mfg's have a max of 10%, higher than that you could be asking for trouble. (voiding warranty &/or safety issues) Overloading the rear of a tow vehicle will also cause all kinds of fun handling issues.

Lower drag/low center of gravity loads can get by with less tongue weight. If you have something high up (a pontoon), it can actually decrease tongue weight a little while you are pulling.

Just did a quick check of 3 big trailer mfg's and their recommendations.

ezloader-10% max
yacht club - 5-10%
shorelandr- 6% single, 5% tandem, 5-7% allowable range

Yeh about that warrantee..... I'm pretty sure this trailer was born as a nice shinny new trailer in the 70s or 80s. Then it must have gotten in to the hands of about 5 different intoxicated rednecks working on it over the years. When I got it it had solid eyelets on each side of the leaf springs bolted to solid aluminum mounts... no shackles at all. So she was trying to rip itself in half on every bump. Like 10 years ago I put the proper springs in it with one oval slider side. It's been pretty good but the load I'm putting on its just changed and it's time for a total fix up on er. Going to weld a Steele boxed axle mount to get rid of all the scary aluminum stress cracks on it. Rollers, actual sleved trailer wiring and most of all balance it right. I've owned a few boats and towed a tonne of them. They all seemed to have right about 50-75 pounds of tounge load by the calibrated arm scale. That puts them lighter than the general rule of thumb but they handle just fine and you can actually pick them up if need be. Now the 10% rule isint universal. That old camper in the back of the phots must have a 600 pound tounge weight, it needs it so it doesn't go ass over tea kettle with 2 people in bed at the back. And that thing tows super well. In my experience I'm not totally sold on the 10% rule. And on something like a boat trailer having extra weight biased forward is just throwing more stress at the long tounge of it. If we call mine an easy loader I would guess that the "no more than 10%" isn't so much for the best towing range, but more so to keep the stress to a minimum on the tounge bar and where it mounts to the rest of the frame. I'm just aiming for enough weight to tow nice but not so much that I can't pick it up to lean it on my own. I towed it exactly once balanced neutral like it is. Let me tell you so you don't have to find out. Yep it death wobbles a truck like crazy.

 

[roscoe]

Just try to get 75 - 100# tongue wt and you should be good.

Much less than that and the trailer is gonna sway all over.