REVENGE 22 Trailer Bunk Arrangment

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
dave3825us
Posts: 10
Joined: Thu May 26, 2022 9:44 am

REVENGE 22 Trailer Bunk Arrangment

Postby dave3825us » Thu May 26, 2022 10:20 am

The SEALION trailer that came with my [REVENGE 22] boat had rollers. All was well until one popped through the boat. I repaired that damage. I removed the rollers and bolted carpeted 2x6 bunks, making fours boards for the boat to sit on, and one keel roller in the front. I am not happy with the outcome. My trailer works, but I am not in love with it. I may buy a second crossmember to mount between the axles on my trailer.

Show me pictures how other REVENGE 22 boat trailers have their bunks set up.


Image
Fig. 1.
[An identifying number has been added to this illustration so that readers can make reference
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what is being shown. This trailer may not be the trailer under discussion but may be similar.
Please add a caption here, under the image, so readers can clearly understand what the
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Image
Fig. 2.
[An identifying number has been added to this illustration so that readers can make reference
to it if there are any comments or questions. This photograph needs a caption to explains
what is being shown. This trailer may not be the trailer under discussion but may be similar.
Please add a caption here, under the image, so readers can clearly understand what the
photograph is illustrating. Alluding to a image in text without clearly identifying the image
by a figure designator makes it difficult for readers to understand what image the
the text was alluding to..--Moderator]

Stayinstrewn
Posts: 20
Joined: Thu Oct 15, 2015 9:16 pm

Re: Whaler 22 roller to bunk

Postby Stayinstrewn » Mon May 30, 2022 8:48 am

[On my trailer I removed the] rollers and put 2x6 [what was later clarified to be pressure treated lumber] in their place. Four in the back, two in the middle, and a couple rollers. This works well for me.
Wasque - 1979 Outrage 22, Honda 225

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Phil T
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Location: Was Maine. Temporarily Kentucky

Re: REVENGE 22 Trailer Bunk Arrangment

Postby Phil T » Mon May 30, 2022 10:25 am

Add one cross member between the axles and install large bunks similar to Stay has posted.

Add a 12" keel roller on the aft cross member.

http://www.Sturdybuiltonline.com is a respected online trailer parts/accessories vendor with many Whaler owners pleased with the prices, shipping and service.

http://www.easternmarine.com has a large selection of OEM trailer parts from the major manufacturers.
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

jimh
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Re: REVENGE 22 Trailer Bunk Arrangment

Postby jimh » Mon May 30, 2022 10:30 am

The most important element of setting up the trailer is keeping the boat as low on the trailer as possible. With a classic 22-foot hull, the hull will not fit between the wheel fenders on a trailer that is only 8-feet 6-inches wide--the typical legal trailer for highway towing. The bunks should be arranged so that the hull chines are sitting just an one to two-inches above the fenders. This gets the hull as low as possible on the trailer. The bunk arrangement will determine this height and position of the boat on the trailer.

The position of the inner bunks should take into consideration any through-hull drains that have a Venturi cover over them. The cover should not be crushed onto a bunk. Similarly, the outer bunks must be located so the aft starboard sump drain and Venturi cover won't be damaged by the bunks.

I have a REVENGE 22. The trailer set up has two sets of bunks on each side of the keel. The inner bunks are close to the keel centerline There are tandem keel rollers sandwiched at the crossmember forward of the first axle, and a single keel roller near the winch post.

Image
Fig. 3. Tandem keel rollers are positioned on opposite sides of the trailer crossmember. In order to raise the bracket to the necessary height above the crossmember, holes have been drilled on the centerline of the crossmember for the two lower mounting bolts to pass through the crossmember. Drilling the holes on centerline reduces the amount of weakening of the crossmember beam strength. The height is adjusted so the rollers make contact with the keel. The actual height of the boat is determined by the bunks. The inner bunk is as close to the keel as the keel roller bracket allows.

Installing the dual keel rollers in tandem and sandwiching the crossmember simplifies installation. If only one bracket is used, then the typical mounting is to use a large flat-bent U-bolt. On larger trailers the height of the crossmember beam may be four, five, or even six inches; finding flat-bent U-bolts of those sizes may be difficult. Having dual keel rollers helps spread the load between them, allowing less friction for the roller to turn.

On my trailer, there are no keel rollers in the rear part of the trailer. They are not useful. When the boat is being launched or loaded, the trailer is always backed in far enough that the trailer's rear crossmember is well below the water, generally so deep that the the stern of the boat will be buoyant and will be lifted off the bunks. The keel centerline will never touch a keel roller at the stern once the trailer is deep enough in the water to have some stern buoyancy. The only time a rear keel roller is useful would be if you never back the trailer into the water far enough to get the boat to start to float off the trailer. If trying to load that way, the winch pull will be trying to pull the entire boat uphill over the rear roller. You want the boat to float onto the rear of the trailer, floating over the bunks and, of course, it will float over that rear keel roller. Once the boat is fully loaded on the trailer, a rear keel roller can help support the boat, but typically the height of that rear keel roller will be quite far above the crossmember if the trailer has non-straight crossmembers that dip in the center. I doubt you can find a bracket to hold the roller that high.

The forward keel rollers are the important ones. During launching or loading, the trailer is at an angle down into the water. As the boat become buoyant and starts to float, it begins to become level with the water, and this pushes the bow of the boat down onto the keel rollers.

The reverse occurs with loading. As the boat is pulled onto the trailer, the keel rollers lift the bow and push down the stern--against the buoyant force trying to keep it afloat.

Image
Fig. 4. A nicely set-up trailer with multiple crossmembers with keel rollers on each one.
As you can infer from this illustration, as soon as the boat starts to be winched onto the trailer,
the front keel rollers will be taking the weight of the boat and lifting it upward as the winch
cranks the boat forward.


In Figure 4 above, the crossmembers are straight beams, without a dip in the middle. The keel roller brackets have been set up with the upper mounting bolts resting on the crossmember, which positions the keel roller very low. The keel rollers in this case set the height of the boat on the trailer. With bent crossmembers with a dip in the middle, typically the keel rollers will have to be raised several inches above the crossmember to meet the keel. The boat-chine-to-trailer-fender fit determines the lowest boat height possible, not the crossmember and keel roller.

The lowest possible boat height on the trailer is desired for several reasons:
  • the lower the boat on the trailer, the easier to launch
  • the lower the boat on the trailer, the easier to load
  • the lower the boat on the trailer, the lower the center of gravity of the boat-trailer combination, which will improve stability on the highway
  • the lower the boat on the trailer, the easier to climb into the boat or out of the boat; a ladder won't be needed
  • the lower the boat, the less concern about vertical clearance when towing and approaching low overhead obstacles, such as motel entrance porches or low tree branches.

With longer boats, like a 22-footer, the trailer is also longer, so you can back the trailer deeper into the water than you can a shorter trailer. The factor that limits how far you can back into the water is usually where the rear wheels of the towing vehicle are relative to the water line at the ramp. Most people do not want to get the rear wheels of their truck in the water. This means that a longer trailer is going be deeper into the water at the end of the trailer than a shorter trailer will be. That is why you often see trailers for 17-feets having an tongue extension--they need to back farther into the water but the truck wheels stop that.

Figure 5 below demonstrates the smaller boat trailer problem and how a tongue extension solves it. With a trailer that is already five-feet longer on a 22-foot boat, you generally do not need a tongue extension.

Image
Fig. 5. To get a 17-footer into deeper water at a ramp and keep the towing vehicle out of the water,
a tongue extension is added to the trailer.


A very important accessory for the trailer is a set of tall PVC guide posts located at the very rear of the trailer. The guide posts serve two important functions: the guides will hold the boat in position on the trailer while it is afloat and the winch strap is not yet taunt, and the guide posts will service a water depth guide for determining when the water depth at the rear of the trailer is sufficient for the boat hull to be generating buoyancy that will lift off the hull from the bunks or at least significantly reduce the weight of the hull bearing on the bunks. On my boat trailer I have a water line mark on the PVC guides. I always back the trailer into the water until the waterline hits those marks. Then I know the boat is going to come off the bunks with ease. Similarly, on loading, I use the marks again, this time leaving them an inch or two above the waterline as the boat is coming onto the trailer. Once the boat is mostly on the trailer, I back the trailer farther into the water until the marks are at the waterline, as this reduces the friction and makes winching the boat to the home position easier.

If you need further explanation of any of my remarks, just follow up with a question.