I have had this idea of using a full length double concave in a board, using the same depths and change in depths as a single conace but using double insted in hopes that it would go rail to rail smoother and maybe have more bite do to the fact that the pannel of each concave would e more dished out. Any ideas, thoughts or experiences with this? Also the kind of double concave is imortant too in my mind theres 3 (maybe they have there own names?) 1st is were the ridge of the double is lower than rail line (like a double inside of a single, dished out within the single). 2nd is a were a the ridge of the double is at the same hight as the rail line ( would be level across the width of the board with concaves inbetween). 3rd is a were the ridge of the double is higher than the rail like (would roll rail to rail if board was placed on the ground). Any ideas, thoughts or experiences? What would you think the benifts and possble draw backs of this would be vs a single?
I have one of those Wilderness ‘Greenough Designs’ edge boards with an almost full length double. The double concave extends far enough forward that it can create a ‘slap-happy’ effect in backwash conditions. In my experience with other boards that had a bit of belly or vee up front, the ride tended to be smoother. They also caught waves easier.
A full length concave board would have to have the rocker really dialed in to avoid the issues mentioned.
Have you seen that video of Maurice Cole explaining his single concave design?
it’s one of his super banana rockered boards with two deep concaves throughout thehwole bottom…
Why?
because just like what Maurice Cole and Jeff Alexander discovered, is that you can end up with two rocker profiles. A highly rockered profile along the outside rail with a fairly flat rocker through the center of the board which has an opposite but complimentary effect.
Loehr and Webber did the Bananas back in the 80’s with a deep single.
Greg splits it into a deep double to lossen it up from the deep single.
Dan Mann did something different with his sweer potato, potatonator and unibrow models which has a super wide and squatty outline. which is to loosen it the width like Mctavish did with his hyper vee bottoms on his mals in the late 60’s-70’s but with concave instead of a flat panel. If you think of water moving at 45 degraees to the stringer you can see why a double would be quicker than a flat when you ar approaching 22-24 inches in width.
the weird thing about that board Greg is holding you picture is that he did both the deck and bottom with a deep double concave, which I don;t understand except for the fact that Bert once talked about how a concaved deck flexing board would morph the bottom into a concave when stressed. But his board were less than 2" thick and up to 24" wide.
They work every time they are tried in powerful surf. Are yhou shaping it yourself or having someone shape it? If the second, let the shaper do their thing. SUPS in hawaii have double concaves with no 2 option in HUGE surf with success. If you are shaping yourself try each option and let us know. The keyword is all this discussion is powerful surf. Sloppy shore break and outside mush burgers might not bring a noticible benefit of any of the three options.
A friend of mine puts a deep single concave (~1 - 1 1/2") with hard edges in the tail. Anyway, they tend to be good boards because of the different rocker profiles. They tend to fit steep waves because the rocker in the middle of the tail is deep and they tend to be fairly fast once trimmed down the line because the rocker profile along the rail is a lot flatter. I have one of his long boards and it is pretty cool. The middle of the tail has about 5" of rocker and then the side rocker is more like 2" at about 8" up…
