We are jumping ahead in the build thread to actually wakesurfing the carbon fiber hollow wakesurf board, because we want to share some stuff with you. Now we should say that this board is seriously ugly externally, we didn’t spend a bunch of time making it look pretty, as we were mostly concerned with how it performed. This post will be rather picture heavy and we’ll try and explain what’s going on, so that you can appreciate the wake / hollow wakesurf board interface
Reviewing the construction and goals of the build, we wanted the bottom of the board to be dynamic. That is to say that the BOTTOM of the board would morph into whatever shape best suited the wake face, within the limitations of the shape of the wakesurf board itself. Remember that there is nothing that connects the deck and bottom of the wakesurf board other than along the rails and the tail. The first thing we want to show is the relative strength of the arrangement. This is a picture of the board getting a 200 pound rider up. The force of being pulled up puts stress on the bottom of the board as the rider is pushing against it and the water is pushing back.
It’s a little hard to explain and you almost have to experience it to appreciate it, but we’ll try. The bottom of the board is dynamic morphing and bending into the shape of the wake and reacting to the water flow. Remember, we are postulating, there is no push, but instead water flow UPWARDS. That’s important in terms of how we want the bottom to behave and how wakesurf boards themselves are shaped. As we are sliding down the face of the wake, gravity is pulling the wakesurf board and rider unit down and the flow of water UP the wake face is allowing the rider to balance those two opposing forces. That’s what’s keeping the board/rider unit on the face of the wake. We’ve seen that unit doesn’t float, it needs to hydroplane to stay on the surface. Ok, so just assume that to be true for a moment. If you were riding down the face of the wake, and also somewhat forward what would be the single best bottom shape to capture that flow up the wake face? It would change wouldn’t it?
It would be dependent upon a number of factors, the amount of force UP the wake face, the shape of the wake itself where the board / rider unit was located, the direction of travel of the board and also the mass of the board / unit rider. Right? All of those things and probably more, within the environment will impact the optimum bottom shape. Obviously we can’t change wakesurf boards every one inch of travel while wakesurfing. Shapers have attempted to manage this by creating shapes that were optimum for a specific set of circumstances, say down-the-line speed, or hard bottom turns. BUT, those were all static shapes and simply wouldn’t work in all circumstances, say when the board is being ridden revert. Compromise. BUT, what if the bottom could change to the optimum shape regardless of changes in the orientation of or envirnonment, generally? Cool, huh? Ok, so THAT’s the goal here. Not sure that we achieved it, but we can say that the bottom of this board did in fact morph to match the shape of the wake.
Try and watch the orientation of the board with regard to horizontal in the next few shots.
Do you see the change?
Guess what it cause? A turn OUT awake from the wake!
What happened with the board, and this is the first time the rider was ON the wakesurf board, is that the bottom shape became more effiecient at capturing the water, that change, rather than being static like with a normal bottom, caused MORE force on the inside rail of the wakesurf board, and the shift from horizontal. Now each of those pictuers is something like 1/10th of a second apart, so it’s very quick although definately noticable to the rider. We should also say that there was a hesitation, or what felt like a hesitation as the board sort of loaded up and then operated on that change. We likened it to a turbocharger spooling up!
What we are USED to, is a static orientation of the wakesurf board, while wakesurfing, to the wake face and a constantly degrading efficieny away from the “sweet spot” which is THAT area of the wake that contains the most upward flow. BUT if the bottom is able to conform to the shape of the wake, regardless of where it is on the face or it’s orientation, then it is constantly improving. We know, that was crazy talk, but lets just say that it was FAST down-the-line and got FASTER the closer you got to the boat. We’d guess this is true with all wakesurf boards, but with this dynamic shape, that optimization occured without regard to board orientation, it seemed to always be improving, once “engaged”.
Ok one more set of comparative pictures. This is with two separate wakesurf boards. Same rider, entry into a surface 360. Now it’s not exactly the same spot on the wake, but it’s really close and our observations bear out the same attribute with the water flow off the opposite rail. In the two pictures, look at the water flow off the opposite rail.
The first picture is the hollow wakesurf board, note that there is no water flow off the nose, or in that area, it’s all off the tail or from the fins back.
The second picture shows a board with a static bottom. It’s a really crappy photo, but look at the water flow close to the nose. That is spray out and away from the board, plus there is still the release off the tail.
In effect what is happening with the bottom is that it shapes to the forces being applied and causes a more optimum water flow down the length of the board. It’s true, we swear!
Here is a quick unedited video of James Walker and his reaction to the bottom of the board changing shape. The deck side had significantly more reinforcement so it didn’t flex, but the bottom DID.
Ok so now what? We don’t really know! We can certainly appreciate that a dynamic bottom shape can create a more efficient bottom and helps channel water flow, but can that be tamed or controlled to the wakesurfers advantage? Possibly aiding landing a wakesurf trick? Thanks so much for allowing us to share that and please come back to follow the rest of the build process and listen to our ramblings about what we can do with this!