Ah Ha! The picture suddenly becomes cystal clear. In my search for a good trailer, I noticed that manufacturers were no longer extending the I Beams much past the rear of the fenders. They were getting the necessary length of the trailer by extending the bunks way behind the last crossmember, sometimes two or even three feet. I suppose the reason for this is that aluminum (and everything else) has been going up in price and trailer manufacturers are under the same cost contraints as any business. The end result here is that the boat is cantilevered way out past the back of the last crossmember forcing that crossmember and attachment to carry very large loads. This is particularly true with our performance boats that have a heavy rear weight bias. With this arrangement, close to half the total weight of the boat may be supported on that one crossmember. Notice how the frame rails extend all the way to the end of the bunks on this older (2003) Loadmaster. Even though it is not shown in this picture, I also have brackets connecting the bunks to each crossmenber.

Good luck,

Dan

There was one pic I was looking for where the seperation was actually in front of the fenders, near the middle of the trailer. Those pics really made me rethink the crossmembers on my rebuild. But you are right about to much weight being carried by a single crossmember.