Hello, Looking for information proper support on our boat lift. I have a #20000 lift. It has 16 X 12" X 4" oak bunks that are straight.
Need info on:
1. span: distance between bunks? (inside distance)
2. support at steps 1.5 "
3. Angle of bunks (needed?)

This is my 27 that was on it last season.

Call Formula, ask for the trailer drawings - every question will be answered. Formula is awesome !

Yeah, contact Formula support. They can send you diagrams of the hull with all the measurements you need.

Yes thank you. I called them and they were very helpful. However, I really don’t want to spend $10K on a custom cradle. Looking for any information on using or modifying my current set-up of 16
foot beams. Any past experience or pictures would be helpful. Thanks in advance!

With the drawings they supply you can make your own beams. Cut them to match the steps and set them at the proper distance based on the dimensions on the drawings. All the data is on there. (I had to do this many years ago for a trailer and your lift setup would work the exact same way)

If you use the 12" tall beams you likely can't do much in spreading or notching them for steps. I would think your old boat had pretty much the same deadrise.

I'm no hoist expert, so its hard to give you a good recommendation other than to call one that sells lifts like that. They deal with your situation daily and have simple solutions. The trailer drawings will give them critical info related to the shape of the hull.

You can build up the beams in the back to match you steps in the hull. Recover with carpet or use a composit material instead of carpet. That is how some of the lift guys around here do it.

I’d do it this way. I went with 12” bunks because my hull has a funny bottom feature that pushes them apart on width. With the steep dead rise in the front it was sitting on the crossbeam when I had regular 8” bunks.

You can avoid this by going narrower if the hull doesn’t have any strakes that prevent it. I also prefer the 12” beam for stiffness. It’s a bear though, I think mine weighed 250lbs

If I remember right a 2x4 laying flat was just about the right thickness for the step. When I would haulout at the drystack I kept a few 24" 2x4's. Stack two up one the rear step and 1 high on the middle step. Worked great

I am sure it is a little different but that is what we did to convert my lift from 29 Outlaw to 38 T/S Gun. Added 2x to rear.