Been watching videos lately but never seen one of his boards in person. He shows up to 1 1/8 inch deep concave using straight edge but then demonstrates that if hold straight edge at 45 degrees to long axis, “it is dead flat”. BUT when he does that demo, the ends of the straight edge are inset several inches from the edges of the concave. Am I correct then that these are more curved sided channels with flat bottom i.e. all the curvature concentrated in outer couple inches rather than curve distributed across an arc?
I have found that esp in surfboard design, people often seem to have pseudo scientific explanations for their shapes that pretty much bunk. But the real key is in the reality of the finished board in a wave with a skilled pilot driving.
I am most curious about the actual bottom shape. Regardless of water flow the boards do seem to work quite well for what they are designed to do.
I’ve watched that video several times and it looks to me as if he puts a fairly consistent edge-to-edge arc across the bottom. There is another video in which Dane Reynolds test rides a bunch of ‘anonymous’ boards including one of Maurice Cole’s. That board did not make the final cut but it is impossible to say why. All the boards except the 5-fin Bonzer looked pretty similar to me. It was arguably an unfair competition as conditions were so variable between sessions. I’d like to think that any board deserves a shot in good conditions. Conditions can make it or break it for a board. https://www.youtube.com/watch?v=dvsDT4nVy-Y
That is what baffles me because it does look like a fairly constant curve but that would be impossible to put a straight edge in contact with all of it i.e. flat no matter what the angle except for parallel to the long axis, the stringer.
I did see that one a wrote it off for same reason, conditions far too variable. And of course rider preference is a big factor. Ross Clark-Jones is certainly in love with them though he mostly surfs pretty extreme conditions, orders of magnitude than I would ever have gone out in even at my youthful craziness.
And of course Dane just grabbed them and rode them. Fine tuning per the rider with the right fin set and placement can make a world of difference, about as far as from crap to magic in my experience.
I’ve tried the straight edge on the diagonal through a concave and if the rocker is just right there does seem to be a flat zone in there. Still not quite sure exactly what his contours are though…
Key piece is for both placements of straight edge (90 degrees across board and 45 degrees) you must have the ends of the straight edge clear to edge of bottom where the rail breaks up towards deck. Wish I knew how to use a graphics program (and had one) so I could draw all this and get my 1000 words across in one.
What he is doing is taking what would be a regular board and then carving out a deep concave down the center of the board but the bottom of that concave is flat , it runs out to the tail of the board , about half the width of the board , the flat bottom on the concave is there cos flat bottoms are faster but the curve of the rocker at the rail gives the turning ability , all the rest is BS
Thanks, so much as I suspected, a flat bottom channel with curved sides. The BS is what keeps his mind excited HAH! Vids show the boards looking pretty fast but faster than any other design, maybe yes and maybe no…
Try it yourself on a scale model, do some ‘finger surfing’ on a table top with it and see. A ‘hull’ that is flat at all angles will be completely different from a rockered out tail with a concave.
I have had a number of boards that were flat out the back, no concave, no vee, no rocker, sort of French curve distribution with all the curve ending at anywhere from right at the pod or up to 6 inches as much as a couple feet forward, depending on the board. I do prefer some tail rocker for sure.
I do believe the concaves are flat across the middle the curve just before the rail. George Gall did a lot of work with Maurice Cole. He has very good insight on those deep concaves.
The company that posted the videos of the underwater flow using the strips glued to the bottom uses a shallower concave that is pretty flat across the bottom and turns down at the rail.
Just blue sky guessing here but could be like with fins size/shape which I played with a lot back in 60’s and 70’s on single fin boards. I used to always carry a 1/2 round file and some wet/dry sand paper in my pack along with one or two spare fins in case I went to far. . At certain dimensions/sizes, a tiny difference in the fin makes a huge difference in performance. But then you can change it a lot more with little impact until you reach another threshold and then again, small change big impact. Fin placement fore/aft made a more consistently felt difference as I would move it around. Might be similar with concave shape and depth though I never played with them at all. I know Dale Solomonson did a lot with concaves, filling and hand grinding with Bondo right on the beach, going out to test between alterations. Really a shame he is no longer online at all as he is a deep reservoir of all sorts of arcane design knowledge
Hi -
George Gall turned me on to the company in question… http://www.cambersurfboards.com/
He (George) is likely one of the smartest people I’ve had the privilege of talking to about this sort of thing. It would be worthwhile for anyone to review his ‘hot seat’ thread.
