Boat bouncing on trailer

[DDavis103]

I have recently bought a 17'10" aluminum modified "V" with a 75 HP Merc.
The boat is great , however when trailering the boat the bow has approxmitly 1-2" of play up and down.
I have tightened the winch as far as it will go but the balance is not correct, it still bounces.
I was thinking of simply using a rachet strap fron the tralier tounge to the bow eyelet to "pull it down" .
has anyone had this issue and is my idea the correct fix?

Thanks for your help

 

[tpenfield]

Re: Boat bouncing on trailer

Usually the winch cable/strap does not exert enough downward force to keep the boat from bouncing.

Check the bow stop to make sure it is adjusted correctly.

if needed you could tie the bow down to the trailer frame, and that would exert sufficient downward force.

 

[foodfisher]

Re: Boat bouncing on trailer

Your idea is right on.

 

[Jerry_NJ]

Re: Boat bouncing on trailer

How does you boat ride/sit on your trailer? My small trailer has rollers up/down the center with bunk boards on either side. One of the rollers is near the front, about as far front as it can be and still be under the boat (this is the most forward support contact point). If you have a similar arrangement, check to see if the rollers are moveable, maybe the one nearest the hitch end can be moved. I strap my boat around the stern, over the rear seat. This forces the boat down against the bunk boards. I usually notice there has been some movement aft from the bow stop... only an inch or so. But I am not aware of any bouncing and I do often check the review mirrors to keep an eye on the boat when towing.

 

[Mi duckdown]

Re: Boat bouncing on trailer

Pics of your set up would help alot. Sounds like a roller adjustment, or addition of a roller.

 

[NYBo]

Re: Boat bouncing on trailer

You need something in addition to the winch strap for safety purposes anyway, so a ratchet strap might kill two birds with one stone.

 

[Thalasso]

Re: Boat bouncing on trailer

At the bootom of your winch post there might be a hole there that sould have a safety chain attached to it and then to bow hook. If not you should have a safety chain there just for the reason if you have to stop quick and boat wants to come forward. Strap might not hold it.
You could put a rachet strap there to keep it from bouncing.

 

[fishrdan]

Re: Boat bouncing on trailer

when trailering the boat the bow has approxmitly 1-2" of play up and down.

If I don't winch my boat far enough up on the bow stop, it will do the same thing. At the ramp, I can winch the boat up to where it is touching the bow stop, but if I leave it there, there is too much clearance once the boat is pulled out of the water. I have to give the winch an additional crank (more-less, dunno) to raise the bow up on the bow roller a bit. Then the bow will sit properly once the boat is pulled out. (There is a scuff mark on the hull where the bow roller needs to sit, so I know where to winch up to.)

Off subject a bit, but does you boat have a bow safety chain?

(edit, I should have said, does the "trailer" have a bow safety chain)

 

[Jerry_NJ]

Re: Boat bouncing on trailer

hum, no safety chain here - now i'm worried. stopping fast is a requirement, not an option.

 

[LilRedNeckGirl]

Re: Boat bouncing on trailer

trailering a boat, you must remember the hull design and its intended function in the water. its designed to LIFT like a wing. That same effect translates in the air rushing past the hull while you roll down the highway.
The winch is intended to pull the boat onto the trailer, then hold it to the bow stop bunk on the trailer, nothing more.
a trailered boat should then be secured with transom tie down straps AND a bow tie down.
We use a heavy strap the goes from trailer, up and over the rear of the boat, then back to the trailer as our transom tie down. the bow is then secured with a shortened medium duty rachet strap, that goes from the bow eye, down to the trailer frame.

 

[DDavis103]

Re: Boat bouncing on trailer

If I don't winch my boat far enough up on the bow stop, it will do the same thing. At the ramp, I can winch the boat up to where it is touching the bow stop, but if I leave it there, there is too much clearance once the boat is pulled out of the water. I have to give the winch an additional crank (more-less, dunno) to raise the bow up on the bow roller a bit. Then the bow will sit properly once the boat is pulled out. (There is a scuff mark on the hull where the bow roller needs to sit, so I know where to winch up to.)

Off subject a bit, but does you boat have a bow safety chain?

(edit, I should have said, does the "trailer" have a bow safety chain)

Thanks for the help, the bow eyelet is against the front roller and there is a "saftey strap" that hooks to the trailer approxmitly 4" below the main winch strap, however this strap is 6" in long so it does not provided any tenshion.
I have just placed a short strap from the trailer to the bow eye and this seems to stop the "bounce", my trailer has no rollers and only 2 bunks. since this is my 1 st all alum boat I was concernerd about placing too much presure on the weld that holds the bow eye.
Thanks again for your help

 

[Thalasso]

Re: Boat bouncing on trailer

Thanks for the help, the bow eyelet is against the front roller and there is a "saftey strap" that hooks to the trailer approxmitly 4" below the main winch strap, however this strap is 6" in long so it does not provided any tenshion.
I have just placed a short strap from the trailer to the bow eye and this seems to stop the "bounce", my trailer has no rollers and only 2 bunks. since this is my 1 st all alum boat I was concernerd about placing too much presure on the weld that holds the bow eye.
Thanks again for your help

I would think your bow eye on a aluminum boat is through bolted.

 

[fishrdan]

Re: Boat bouncing on trailer

since this is my 1 st all alum boat I was concernerd about placing too much presure on the weld that holds the bow eye.

My 18'er weighs in at 2000#+ and I crank it up the last 6-12" with the winch. There is a lot of tension on the strap and bow eye, but it goes. I have a bunk trailer too, and one tip is to make sure the carpet is completely wet, dunk the trailer in too far then pull forward if you needed (I have to do this as part of my bunks stick out of the water when the trailer is backed in to the right depth.)

You can put the bow strap on to hold it down, but I think if you pull the boat further on the trailer, it will solve the bouncing.

Post up a pic so we can see how the bow is sitting against the bow stop.

 

[BatDaddy1887]

Re: Boat bouncing on trailer

+1 for tie-down straps on the transom and the bow....

 

[Home Cookin']

Re: Boat bouncing on trailer

first, be sure the boat and only the boat is bouncing. From the rearview, it may look that way but it's the whole boat+trailer moving. If that's the case it's out of balance.

if the trailer has a break, it may be bouncing against that if it's not ;atched tight.

I would want to raise my front roller to support the keel rather than pull the hull down at the bow and risk bending/warping the hull. That's not what they are made for. If you must do it that way, release that tension for storage.

And get a safety chain, to prevent the boat from rolling off the back of the trailer if the winch latch fails. They are not very secure.

 

[ufm82]

Re: Boat bouncing on trailer

Pictures are needed. There are a myriad of things that could be causing the issue:
1) Bunks are not adjusted properly, causing the bow to ride high and not maintain contact with the bow roller
2) Winch strap pulling up on bow eye as opposed to pulling straight/down on bow eye. This could be as simple asd the strap being reversed on the drum.
3) Bent trailer ( unlikely but have seen it- tongue bent downward causing a "hump".)
4) Bunks extend too far forward which do not allow any weight to be transferred forward.
5) Winch stand/bow stop is too high, pulling boat up off bunks and allowing motion.

Pictures of the bow eye/bow stop area would be good as well as bunk layout.

 

[fishrdan]

Re: Boat bouncing on trailer

I would want to raise my front roller to support the keel rather than pull the hull down at the bow and risk bending/warping the hull. That's not what they are made for. If you must do it that way, release that tension for storage.

I was thinking the same thing, but didn't mention it.