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I can not show you the new fin from Denali


Horton
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@cruznski I have one of those fins also, it was next on my list to evaluate. Yes very thin small wing. Currently enjoying swerving with another unique shape which exhibits many of the same characteristics.

Mike's Overall Binding

USA Water Ski  Senior Judge   Senior Driver   Senior Tech Controller

 

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@mmosley899 ah yes, 'tis good to know the old fin warriors are still out there. One must admit the slot makes the shallow v deep conversation a wee bit more complex. For one thing, the slot fins were really nicely made and finished and I recall on old Goodes they were a +.
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Schnitz has his NEW Slot Fins for sale on his Web-Site at SCHNITZSKIS.COM. I used the old ones for years, especially on Goode's and they made a huge difference. Pulled this off his site.

 

My new and improved SlotFin. Same shape, minor upgrades! $149.99 plus $6.99 SH in the USA. Outside the USA, shipping costs will vary.

 

PS: GREAT VIDEO !!!!!!!

 

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But I can show you some fins from Ernieanwet2vg7cdk.jpg

xecptv4hhw72.jpg

 

Back in 2003 I designed about 30 fins, made about 15 of them. Will and Paul of D-3 tested some of them. My fav was the top loader, you didn't want to be hard in the turn, but the more you loaded going to behind the boat the tip of the ski could pull to 90 degrees to the boat. That's what a crazy auto designer does, that loves to ski. P.S. loved the Carbon Fins.

Ernie Schlager

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I have a decent grasp of the aerodynamics and hydrodynamics of the the water sports I enjoy, and yet slalom ski fins confound me. Perhaps someone who understands better than I can explain a couple of things. Why do we not use foiled fins and what's up with all the holes?

 

The basic shape I get. It's essentially a delta wing which doesn't reach a point of stall as angle of attack increases, it just continues to loose lift. This makes sense as the fin never completely stops working, it just slides more the more it's pushed. The problem is, it's not a particularly efficient shape, and when you punch a bunch of holes in it, you make it worse. I may do this experiment my self, but I would wager that if you were to draw a line connecting the edges of all the holes, and then cut the fin along that line, it would perform nearly the same.

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I'd recommend you keep that wager small @wilecoyote ... and you'll want video rolling right from the pullout. It feels a bit like dress shoes on ice. You can walk around okay, but it feels insecure enough to discourage any thoughts of running.
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@wilecoyote the holes act as pressure relief.

 

If you think about a fin under static pressure - you can define it with center of pressure and amount of drag. The problem is with that thinking is that the angles and pressures are never static. A slalom turn is a long dynamic slide where the angles are constantly changing. Even Adrian Newey will admit there is alchemy in the science.

 

As a side note - I believe that the standard fin shape is the way it is because it is easy to make by hand - not because it is best. Back when I made CarbonFins I made hundreds of fins by hand. The standard shapes are easy to make and arguably organic.

 Goode  KD Skis ★ MasterCraft ★ PerfSki ★ Radar ★ Reflex ★ S Lines ★ Stokes

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@wilecoyote you bring up some good points. Without getting into too much detail though you have to understand that the fin on a ski is definitely NOT intended to be as efficient as possible. It wouldn't be very hard to make a super efficient fin...but it would make for a terrible ski ride.

 

The fin is asked to do a lot of things, as @Horton points out. We want the ski to be fast behind the boat, and hold direction off the 2nd wake, while keeping the tip high enough to keep the ski going out, but low enough to still be efficient. Then we want the ski to slow down coming into the turn, while at the same time we want the ski to start to rotate, then as the speed drops dramatically we need the tip height to be stable as the tail slides through and the ski starts to point across course. Then as the line comes tight we need the ski to be stable without getting behind us, and when we start to pull we want there to be the most acceleration from the ski with the least amount of load/drag so we can start the process over again.

 

It's a lot to ask. It's also why setting up a fin can be so challenging, and despite popular opinion, the fin effects all of this, not just the preturn and turn. So yes, holes add drag, but at some points we want drag, and depending on the angle of attack of the fin and the location of the holes, they do different things, and it's more than just pressure relief.

 

As Horton said there is some alchemy there. This new fin is the result of years or testing. We may have an idea that makes sense on paper, but then we need to build lots and lots of different prototypes, testing and tweaking to try and learn what's really going on, and what works the best. This whole process has been really fun.

 

 

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I did not do a direct compare between the old fin and the new fin but whatever was going on today it felt really crazy good. I can not comment on the specific claims about the fin shape but I am 100% sure it does not suck.

 

If you do not believe me as @Rico if I was excited after my second ride.

 Goode  KD Skis ★ MasterCraft ★ PerfSki ★ Radar ★ Reflex ★ S Lines ★ Stokes

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Playing with fin design is fun and very interesting. However it can also be SUPER frustrating. The challenge lies in understanding what is really going on down there under the ski. Contrary to popular believe, the hydrodynamics on the fin go FAR beyond the simple concept of 'location of surface area' and pressure relief.

 

Anyone who invested time trying to decipher fin design will tell you there is some 'black magic' going on. The surface-area and pressure-relief arguments that @Horton eludes to, do have merit and are valid under certain circumstances. However, I find that explanation falls apart and does not hold true under ALL conditions/situations the fin is exposed to within the slalom course.

 

The new Denali fin takes advantage of some of those 'black-magic' hydrodynamics and brings a new level of performance and tune-ability to the water. We are just scratching the surface of what is possible, and I'm more excited then ever to be on the water digging deeper into the rabbit hole.

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@JAS the reason for the ridiculously silly video I made about this fin is that there is another "feature" of the fin that @AdamCord asked me not to show. At this time of year I can not really do an A/B comparison between a fin with and without the "feature" but my guess is that it really makes a big differnece. Until the Patent Pending stuff is all legal I think they do not want me to say more.

 Goode  KD Skis ★ MasterCraft ★ PerfSki ★ Radar ★ Reflex ★ S Lines ★ Stokes

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