Rollers to bunks

tboltmike

Petty Officer 1st Class
Joined
Aug 17, 2006
Messages
340
I like the rollers because I can launch and retreive without getting the wheel bearing wet. I rolls off by it own weight and the electric winch makes for quick retreival.

However, when replacing some deck wood, I noticed spider cracking on the interior of the hull. Mind you, the hull is 35 years old. It was more like surface cracks. The areas were sanded down good and several layers of woven were laminated in.

This got me to thinking about bunks. Answers to several question, please.

Will bunks better support and spread out the load? This is an 18ft trihull, loaded about 2,000 lbs. The trailer's cross beams have 4 ft. spacing?

What length of bunks and how many across are needed?

Will bunks require sinking the trailer to float the boat on?

How much of the load does the centerline roller carry if any?

Any idea of the cost?

Thanks for bearing with me on this question.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: Rollers to bunks

if you bearing seals are properly installed, no problem, they should be service every year anyway.

yes you have to go a little deeper, yes it distributes the load better. keel rollers are for loading and centering the boat, not support.

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bunkbrackets004.jpg
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Rollers to bunks

My boat is quite a bit heavier, closer to 3K lbs, I put those nylon teflon pads on the bunks, it easier than carpeting again.
 

tboltmike

Petty Officer 1st Class
Joined
Aug 17, 2006
Messages
340
Re: Rollers to bunks

Thanks for the replys.

How do the rollers help load without providing support? I've seen some trailers that have retractable rollers, but not practical on mine.

How much of the length should be supported by the bunks and how may across should be used?

Thanks, Mike
 

jonesg

Admiral
Joined
Feb 22, 2008
Messages
7,198
Re: Rollers to bunks

I've seen trailers with 2 per side, I have one 2x4 per side with four 12 inch x 4 inch pads on ea bunk. I have a keel roller to keep the bow from banging the frame and will be installing a centering keel roller at the rear cross frame to get the boat started on the triler correctly, I also have vertical side supports which will be welded to the frame later.
Never had a problem with just one bunk per side.

My bunks sit above the trailer frame so I put wooden supports to keep the 2x4 from flexing , I installed them between the frame and bunk.
I tried 2x6 on edge but it didn't work for some reason, can't recall why.

The bunks I removed from my first railer were covered with rug and I suspect the carpet kept the bunk wet which rotted the wood.

either way you do it, its a lot less maintainance than rollers.
 
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