fishtailing

N

norman

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Can "fishtailing" be the result of too much tongue weight..or not enough?

I've noticed some slight sway lately while towing my Doral and want to reposition the boat on the trailer to try and eliminate it.

The last time I retrieved the boat I noticed it was a couple of inches farther back than usual.
Would that be enough to cause some sway?
 
Fishtailing is the result of too little tongue weight. The shift back might cause it.
 
they also make dampers that can help but you do need the correct tongue weight to begin with
 
Thanks guys.
That makes sense. If I pull the boat a little farther forward that should correct the problem.
What's that old adage...as much weight over the axles as possible.
 
You want 10% to 15% of the total trailer weight to be on the hitch. Then, too, springs, shackles, u-bolts, wheel bearings, etc. all have to be tight and/or properly adjusted.

Lar.
 
Make sure you have trailer tires, if someone has put radials on the sidewalls are made to flex for cars but will result in fishtailing on a trailer. Trailer tires are bias and heavier walled.
 
Thanks Dan. Good Point. I'm pretty sure they're trailer tires but I'll double check.
 
I have radial tires on my boat trailer as per my tire guy. Boat and trailer weighs 3600 lbs, trailer single axle. He said ST tires are only for trailers with heavy equipment. I have made 9 yearly round trips to Key Largo, FL, 1425 miles each way and no tire problems. I replaced them because of wear two years ago. I'll stick with radials.
 
My trailer tires are radials. Goodyear Marathons ST225/75R15. Made for trailers. Goodyear doesn't make bias ply tires for trailers anymore.
 
I may have misspoke about radial but when checking here only trailer tires for reason I gave in my first post. Here in the rubber capital, Akron, Oh. If you tell them it's for a trailer they will only sell you trailer tires, they tell me for their liability.
 
One thing I have found out myself and thru friends and that you do not want to change the configuration of the boat sitting on the trailer! Slight changes cause exaggerated problems. You said the boat is sitting further back on the trailer which explains the fishtailing. Put it on up to the bow roller like it was before and you'll be fine.
 
Here is another important fact I learned when towing a camper.

If its dual axle ( 4 tires ) and you have to much weight on the front set, the trailer will dance around behind your tow vehicle.

A simple cure is to raise the height of your ball and it moves more weight to the rear set of tires and tracking is instantly 100000% improved.

All I had to do was to flip my 3" drop receiver and remount the ball on the top and it was instant cure.

I did this at a rest stop on the way to Maine with a new camper that we had never towed before.

We tried moving stuff all around inside the camper with no luck, and then another guy with a camper saw me screwing around and told me the cure.

I did it and it was a lesson learned for life.

I know after all of this typing you are going to come back and say "its a single axle trailer" but maybe this can help someone else.

Fini
JLC
 
Thanks Gary,

That's the irony. The boat was at the bow stop or bow roller...but what I hadn't realized was that the whole bow stop/winch assembly had moved back...just a bit.

What happned was..the u-bolts that hold that assembly to the trailer frame had loosened...ever so slightly. As a result, every time I retreived the boat that same assembly would move back just a hair.
Eventually, the boat and trailer began to fishtail and when I examined things I noticed the boat was back a few inches more than usual.
Thus my original question about the tongue weight... and as you said, and as I learned, even a small change can make a big difference.
Since then, I moved the bow stop back to it's original position...the boat sits where it always did and the whole rig travels as straight as an arrow.

JLC...actually it is a double axle and I did the same think you did with the receiver when I first got the boat a few years ago and you're right...it made big difference for the better.

Thanks again.

Thanks again.
 
Years ago a friend had a pop up camper mysteriously start fishtailing on the way to a weekend getaway. The culprit? A watermellon. Move from back to front, problem fixed. It doesn't take much.
 
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