so what do you all think about the side fins having a slight concave on the inside edge?? read a article about it, and makes all kinds of sense. when are the fin mfg. going to kick down the design??
I also read a few articles on it and the futures had good feedback though Tom from redX (i think) said that they tried it and the difference was negligible. Tom also suggested to try it yourself. Take sandpaper or better yet a dremel tool and foil the inside of your fins ( a little bit behind the leading edge).
Mcabe is talking about concavity. When we injection mold fins, we try very hard to avoid sink. Sink is when thicker sections of plastics shrink more apparently than the thinner surrounding sections. I metioned that if people really wanted concavity on the inside edge that just makes our job easier. Shaping a 20/80 foil onto the leading edge with some sand paper was the suggested I made about the ability for people to test the theory with their existing fin system.
,With my Superchargers: A FEW YEARS BACK, I started leaving the “sink” on them as Tom mentioned in his post,(Tom and I have had a few conversations on this subject in the past). In most cases it was a - rather than a + .Around the turn of the century I noticed that if I back foiled the inside edge a 1/4-3/8" on the tip and tappered it down to the base on both leading and trailing edges,but leaving the major portion of the inside of the fin flat, that they were even more effective in drafting w/o creating extra drag. ,I also use this method on my main outboard fins with great success. ,I noticed that some fin companies are following suit.3 YEARS LATER:I saw a pair of D.Takayama sidebites with this same back foil…hummmmm coincidence? or just good R&D on his and my part?Herb
Hey Herb & Tom,>>>>>>>>> By this, Herb, you must mean that the leading and trailing edges become more symmetrical. Not to get hung up on terminology, it’s all just words after all, I’ve refered to the technique as easing the leading and trailing edges. I believe we’re saying the same thing. The work sink is an interesting way of discribing things and I’m not completely clear on it. I’ve been working a concave into the inside surface of rail fins of late with very possitive results on my boards and the feed back is possitive as well. What do you guys think about the cross section of the new Future Vectors? So what do you guys think about channeling fins? I’ll post some photos of a channeled set when Mike gets back from vacation. Back to the fin shop, Rich
The “vector” foils from Futures work. The extent that they work is very user (surfer) and equipment (surfboard) dependent. They provide lift, drive, and sustain projection with great control. Their performance is a result of the excellent design and foil applied to the fins. You will not find any flat spots on these fins. NO ! I do not work for or have any commercial interest in their company !
so… what size & type of board have you tried them on? In what kind of conditions? Any problems with them causing excess load on the board (stress cracks, etc)?
Keith, Riding a 63 18 3/4 x 2 3/8 with 14 inch tail @ 12 squah steve coletta/natural curves. First tried the vector foil in 2 to 3 foot gutless wind swell (was using 4 oz glass fins earlier in the day - very good fins to begin with) at Sewer Peak / Pengies. Noticed three things: 1) the whole board had extra “lift” at take off - really an asset setting up a wave; 2) loading the rail experienced significant drive and projection; and 3) really easy to hold the board on rail. I really was a little apprehensive that the “extra” lift and acceleration could be too much in a powerful wave. Surfing the two headed south swell (June 8 - 12) in the same line up, found those fears were premature. Same board - same fins - same results “ratcheted up” with the amplitude of the swell. It’s not rocket science, but an excellent idea based on correct laminar flow, well executed by the fin maker, yielding a cool result. My intuition tells me the design and quality foil maximize laminar flow, reduce drag and cavitation, and provide lift and leverage off the inside surface of the fin. SURFING IS REALLY FUN ! ! !