I will describe the arrangement for my REVENGE 22 trailer in a narrative and with some illustrations
The E-Z-LOADER trailer is a c.1992 model TEZ 19 - 22/24 5200-lbs, a tandem-axle trailer, and it uses a combination of keel rollers and bunks. I have replaced all the original black hard-rubber rollers and stops with new "poly" yellow-orange rollers, new brackets, new shafts, and mostly new hardware.
There is only one set of keel rollers and they are mounted on the forward main crossmember of the trailer frame. (A
crossmember is a transverse structural support that crosses between the two main longitudinal supports of the trailer.) The bunks are mounted so they begin at the boat transom and extend forward along the hull until the V-hull shape begins to change from a nearly constant moderate deadrise to a much deeper V shape.
The keel rollers are installed in pairs, two rollers on one crossmember. The brackets sandwich the crossmember and are held in place with straight bolts, not U-bolts. To raise the height of the rollers above the crossmember, I have drilled two holes through the crossmember (on its exact vertical centerline so as to minimize any loss of strength). The lower mounting bolts pass through the brackets and through the crossmember. The upper mounting bolts pass through the slots on the bracket and just lay atop the crossmember.
- Fig. 1. The crossmember of the trailer frame has been drilled to permit the roller bracket to be mounted higher. An identical bracket and roller are on the aft side of the crossmember, but not easily seen in this view.
- drilledCrossMember.jpg (35.94 KiB) Viewed 1742 times
- Fig. 2. The rear roller of a pair. The upper mounting bolts just lay atop the crossmember.
- rearRoller.jpg (64.74 KiB) Viewed 1738 times
My trailer's bunk arrangement is somewhat unique. There are four bunk supports in total. These are arranged in two sets, port and starboard. The bunks are attached in pairs to a frame. The frame pivots to fit the bunks to the hull shape. The distance between the bunks on the pivoting frame is adjustable.
- Fig. 3. The bunks are position so the outer bunk is well clear of the hull runner. The inner bunk is as close to keel center line as practical. Note the longitudinal tube that supports the bunks and allows them to pivot to meet the hull shape. This is an unusual feature.
- trailerBunks.jpg (104.03 KiB) Viewed 1747 times
The outer bunks are arranged to fit inside the hull runners, and particularly to clear the venturi cover on the through-hull drain on the starboard side. This prevents the drain cover from being crushed if the were loaded onto the trailer with the bunk right under the drain.
The inner bunks are as near to the keel centerline as the trailer brackets allow.
The two bunks can move on their pivot. This automatically distributes the weight on each bunk.
- Fig. 4. The bunks end when the hull shape changes to a deeper-V toward the bow. Note the other through-hull vent cover; the bunks should clear this obstacle, too.
- rollerMount.jpg (65.84 KiB) Viewed 1735 times
The overall height of the boat on the trailer is controlled by one factor: the clearance between the hull chine and the top of the fender. This is generally the controlling influence for any boat on any trailer if the beam of the boat is wider than the distance between the trailer fenders.
- Fig. 5. The hull chine clears the trailer fender top by about 1.5 to 2-inches, depending on how evenly the boat comes onto the trailer.
- fenderClearance.jpg (33.93 KiB) Viewed 1748 times
On my boat-trailer rigging, the separation between the top of the trailer fender and the boat hull chine is about 1.5 to 2-inch. I have seen some rigs with even less clearance, about an inch.
The absence of a keel roller at the far rear crossmember of the trailer is not a serious defect, in my opinion. When launching or loading, the stern of the boat enters the water and its buoyancy creates a lifting force that reduces the weight of the boat on the aft part of the bunks. The boat comes off the bunks very easily and slides onto the water easily--sometimes too easily .
The buoyant force of the hull toward the stern as it immerses in the water tends to push the forward part of the hull down hard onto the keel rollers. This is where the keel rollers excel. The boat just rolls on the keel rollers, and the downward force on them does not prevent movement of the boat.
- Fig. 6. The bow winch is positioned so it pulls upward on the hull. This reduces friction when loading. After the boat is fully forward, the stem should rest in the bow winch roller, as shown. Before highway towing, a second strap is installed to apply a strong downward force to the bow eye to reduce any tendency for the hull to bounce up when encountering a highway bump.
- bowWinch.jpg (99.02 KiB) Viewed 1741 times
The single bow roller seen in Figure 6 is important. It forces the hull to rise as it approaches the winch stop-roller. This reduces the force that must be exerted on the bow eye to get the boat into proper position. While the stern of the hull is still immersed in water, its buoyant forces are trying to push down the bow. This roller prevents that movement. The bracket is a bit clunky; it works, buy a cleaner solution should be possible,
You can read more about my trailer set-up in a very similar post at
TRAILER SET-UP
https://continuouswave.com/forum/viewtopic.php?t=4759You can read more about my various renovations of the trailer hardware in a post at
TRAILER REFURBISHMENT: 1992 E-Z-LOADER
https://continuouswave.com/forum/viewto ... =6&t=3874l