I have twice now seen wilderness boards with a crazy stepped rail configuration, for lack of the correct terminology. See my lame attempt at creating a drawing of what this would look like in profile.
I thought I’d ask you all if you have knowledge about what this is designed to do. The only thing I can come up with is that if the board is on a perfect plane, it would reduce the surface area in contact with water. However once up and riding, I can only guess what this might do.
Any ideas?
–BCo
I thought I’d ask you all if you have knowledge about what this is designed to do.
It’s designed to cause a seroius headache on the glasser.
Side-effect: Headache also on the sander.
Probably also produces what is known as rails that catch.
its a Greenough design that Bob Duncan puts on a few of his boards, Lets the board run on triplane hull bottom, but when you bank the board into a turn it has a softer more forgiving rail. Bob and Charlie Coffee have some nice shoter boards with a 2 plus 1 set up with that bottom that work really well. IMO.
I have made two boards with edge bottoms and they DO NOT catch. They come alive if you bank them hard. There is no real advantage to them if you just swivel them around. Like Kirk says, it is a nice way to combine a soft thin rail with a flat planing bottom. I’m working on a new single fin edge bottom with a flex tail as I write. Pics soon…
They are called Edge boards. Good stuff, and have had a lot of influence on my personal design theory. And no, they do not catch, the soft rail seems to protect them from penetrating too deep and running. Here’s an Edge Spoon kneeboard build I did a while back. -Carl
http://www.swaylocks.com/forum/gforum.cgi?post=257035;search_string=edge%20board%20CarlOlsen;#257035
I’m not privy to the actual ideas behind the concept but I have had a couple of the Wilderness edge boards. Surfer’s Journal showed a pic of George Greenough and Mike Cundith with a shaped edge board way back when.
I can think of how mine might work on several levels…
Thinner more sensitive rails with a thicker hull for flotation.
A channel along the underside that, like any channel, directs water. Greenough has a long history of boat designing and similar chine-like concepts are apparent on some of his hulls.
A way to deflect water off the bottom creating lesser wetted surface.
Adding stiffness after glassing - like deck channels. Both of mine were pretty stiff but had enough tail rocker it didn’t matter. With double stringers, I feel pretty safe in regards to board breakage and fin box security.
Mine have both had deep dual concaves. The boards seem to ride best in trim with rail engaged in a steep face which I believe is the type of wave for which the design is meant. Mine seemed to find a nice track on their own and felt stable at speed.
I have had slap/bouncing issues when droppin in “flat” (i.e. not on edge) in chop or backwash. I attribute this to the concaves.
I can also remember catching a forward edge just prior to landing a drop and squaring off a bottom turn. I’m not blaming the board… just pointing out that any board can catch an edge. FWIW the 9’7" is a favorite of mine.
In phone conversation with Bob Duncan, he implied that the forward entry of the edge/step has been an area of experimentation. Sure enough, on one of mine the edge is carried all the way to the nose. The other fades in farther back. Check the pics on my edge board posts…
Wow, thanks everybody! Keep the info and stoke coming!
Neira,
Yeah, I have enough trouble glassing and sanding, can’t imagine doing those bad boys and keeping that edge sharp.
Deanbo,
That is kinda what I was thinking, but sounds like the consensus indicates that isn’t an issue…interesting.
Kirk,
Thanks for the background. How thick were those shorter ones?
LeeV,
Nice boards, guess you like the edge the edge gives you. What can you say about the size of the edge, and placement relative to the rails?
Carl,
Wow, nice work. I am truly inspired.
EPac and John,
Thanks for the links, and John, thanks for the info and insights. I must say, I am intrigued.
Pierre,
I too am speechless.
–Ben
Pierre,
I too am speechless.
–Ben
Hehehe ! Sorry about that one. My post was just a set of pictures from the archives. I deleted it after I noticed it had already been posted
above.
The edges are 1/4 inch deep. The distance from the rail, for me anyway, is a bit mysterious. If I am shooting for a real rail turner like my single fin, then they are a couple of inches in. For the tri fin, the edges are a bit closer. I think the way I treated the edges coming off the tail worked better on the tri fin.
If you combine the edge with a down or blocky rail, I don’t think you’ll get any performance benefit. It will, however, definately feel crisper than your standard tucked edge.