New CG Fin from Denali

[Bill22]

@adamhcaldwell Thanks. I was thinking of using a Dremel and file but I want to keep the top edge as perfectly flat/smooth as possible.

[Adam Caldwell]

Sure. You can reshape it any way you need to.

[skialex]

@Bill22 dremel is my best tool, but in this case better use a flat hand file. Try to file all the area at the same time, either by using a wide hand file or filing diagonal. Clamp the fin on a vice (level) and try not to file at an angle. Edges should be 90° at all time. If you want a smooth finish use wet sand paper on small block. Leave the edges where the adjusting screws touch sharp, but break the corners and smooth the edges of the part that sticks above the fin block.

Do this and your fin would look like it came like this out of CNC machine.

:)

[skialex]

 

This is an idea of what to do if your dft adjusting screw is not long enough and you can not just go to a hardware store to buy one.

Made this for @Stathis Ventouris to use with his CG fin

[aupatking]

Anyone running the CG on an Alpha? I just put mine on yesterday and can only get about .735 out of it, even with some minor filing. I haven’t been able to ski it yet, so curious if I should go ahead and file it more before I do.

[JayG80]

Adams... Can you build the ski with binding inserts for MOB/OB4 binding plate?

[Adam Caldwell]

@JayG80, I thought the MOB system was universal?

[Bill22]

@aupatking do you want me to send you one of the custom set screws? I had to buy a 10 pack. PM me your address.

[JayG80]

MOB is a Universal plate except for two forward holes like on HO A2. Their temporary attachment is an adhesive but I’d want inserts at the front toe release. http://www.mobsystemrelease.com/

 

“The MOB release system has been installed on an aluminum plate which mounts directly to your ski's binding inserts. If your ski insert pattern does not match, you may need to install additional inserts, or modify the mounting plate slots. The spring housing area should be attached with an adhesive material such as 3M Auto Trim Adhesive. This may be used for extended time with careful monitoring by the user.”

[Adam Caldwell]

@aupatking - file away until its a the right spot. If for some reason you manage to destroy the running surface in the process somehow just let me know. I can get another one out to ya.

 

[BraceMaker]

@JayG80 I know that's one of my issues as well. I have a micro just but need to release the tape move the plate and retape it.

 

For dual boots you need tape front and rear.

 

Trick skis often have another forward set of inserts and In theory Mike could redesign the plate for that style of ski and skip the front plate.

 

Another approach I have been working on is a delrin block that is taped down so the mob plate is contained but can slide if you loosen the mounting screws.

[aupatking]

Thanks @adamhcaldwell I’m going to try a couple more fin boxes to see what let’s me get the most forward adjustment before I file much more. I stuck my MAD block on my new Alpha, just because I like the setting on the Syndicate fin so I could do a quick drop in change if I want. Long story short, the rear, downward set screw doesn’t allow much forward movement. I’m going to try another HO block and possibly a Vapor block. At some point I’m just going to cave and order a damn C75

[Adam Caldwell]

I know @Horton thinks we are 'Crazy'. So whenever I can get some positive reinforcement on our designs I'll take it.

 

Retired Boeing tooling engineer - who I gave a couple of old 3.1 skis to several years ago- randomly pops in my shop last week to see what was new.

 

I handed him a CG fin and didn't say a word knowing this guys is a high level power nerd like me.

 

He stared at it for about 60seconds turning it over in his hands, and then the 'holy $h!t" i was was expecting to hear.

 

He then proceeded to highlight almost every critical design attribute the CG fin brings to the table. This particular individual is not a high level skier, but has extremely broad knowledge of hydrodynamics and aeronautics - well beyond what I'll ever know.

 

Several of the fin characteristics he mentioned we have never discussed publicly (and don't plan to), but it was clear as day to a 'trained' eye - which was very cool to see that he was able to pick up on it. That was a very cool experience for me, and just helps validate and further cement the design concept in stone.

 

 

ALSO,

I heard today from @AdamCord that the a new stock of CG fins will be arriving less than 2 weeks!!

 

As previously mentioned, there is a NEW ADDITION, to the Denali CG fin family in this next run. For those who have been sitting on the sidelines watching but afraid to get you feet wet out of fear of needing to 'tweak' the setup, this next one is for you. Literally plug and play. ZERO setup required. Unless of course you want to turn the volume up to 11 and explore new found potential!

[DangerBoy]

@adamhcaldwell @AdamCord I understand your gear is optimized for and/or targeted at 34 mph course skiers but I'm curious to know what would/could your CG fin and/or CG Fin C75 combination have to offer a 31 - 33 mph skier? Do the advantages of your designs only really start to appear at higher speeds or are they still noticeable at slower speeds? And what about longer line lengths like 22' off? Has anybody been testing your stuff at lower speeds/longer line lengths?

 

What about for a free/open water skier? I know it's hard to quantify benefit or performance gain on an open water skier because you don't have number of bouys made at X rope length to use as a yardstick so think more in terms of what's important to us free skiers; stability & foregiveness, easier to crank wicked turns, gettin' lower, throwin' bigger spray, impressin' the ladies and all that good stuff ;) I generally ski 31 - 33 mph at 22' off although I'm thinking of giving 28' off a go this year just for grins.

[Stathis Ventouris]

@skialex excellent job it is working nicely!

[paul413ski]

First sets of the year - holy sheep dip what a difference both sides of the course lff on a 2018 69.5 Vapor

[chlotan]

my girlfriend bought a cg fin to mount on my HO superlite tx....anyone have any idea or experience setting up the cg fin on something other than a denali c65 ski? I'm trying not get wrecked the first time on the water with this thing.

[Drago]

“ after a year of testing most people are liking .010-.020" shorter and deeper, as well as 1-2 degrees less wing from their original settings.”

[Ed_Johnson]

@chlotan...I've set the CG Fin up on three 2018 top end skis, and found out in all three cases, that the Stock Fin is more sensitive than the CG. My recommendation is to set the Stock Fin up to the very best it can be, then switch the CG to those exact settings. The only difference is wing. Mine is 5 degrees. Anymore than that just adds drag. 7 degrees would be the absolute MAX. Keep in mind that the wing is way lower on the CG than the stock fins.

 

 

[chlotan]

anyone have any idea about using the fin without the wing?? how performance might be effected? also, how can we purchase the specific denali wing for the cg fin?

[skialex]

@chlotan no offens, are you familiar with fin adjusting? Do you have the means to adjust a fin? If yes by what I understand you should start at your standard fin numbers or factory numbers and work from there. Otherwise find a fellow skier to help you with the swap!

[Horton]

75k page views for a fin?

[BraceMaker]

@chlotan https://www.ballofspray.com/forum#/discussion/20424/using-denali-fin-what-wing-are-you-using

[aupatking]

For the last 2 years for Radar and this year for HO as well, both companies have released 2 sets of numbers, Long/Shallow and Short/Deep. Have any of you found that one suits the CG better than the other?

It sounds like, if stock, you go shorter & deeper. Would that also be true for the S/D settings: still Shorter and Deeper?

I like the Alpha at L/S with the standard fin but went into no-mans land chasing a fin setup with the CG. I don’t really have the time available for 2-3 sets a day a couple or more days a week to iron out a setup, so I’ve just stuck the standard back on. I really want to get the CG back on this ski, as I’m sooooo much earlier, even with a bad setup, but it’s insanely inconsistent right now.

I’m going to try @Ed_Johnson advice and go straight stock, as I think I started at slightly shorter and further forward numbers last time.

It would just be nice to skip the L/S goose chase with the CG if I just should have started with S/D to begin with.

[MattP]

@aupatking What are you feeling with your set up? What part of your skiing is inconstant in the course?

Have you tried stock but just decreasing the DFT? I ended up DFT -.05 & Length -.06 from stock Deep & Short on a Vapor.

[aupatking]

@MattP I had gone forward with DFT, but was trying to make leading edge neutral moves, unless I felt I needed them. I’m not consistently getting the tip down, especially into offside so I was adding tip and adding tip. Even moved the boots forward. Moved front binding forward 1/8, then back 1/16. I have been able to ski so little that my adjustment last night might get tested as early as Friday, if even then. So, all I’m wanting is some DECENT base number.

It says great things about the fin but there’s just conflicting data. Some saying go short and forward, others say go DFT back. To me, DFT back while still getting proper tip engagement means a lot of length, right?

[aupatking]

So to clarify, .750 DFT would be now .700, right?

[paul413ski]

Stock settings back 0.30 thou worked great for me on my Vapor Reducing dtf will also help with tip pressure into on side leave length were it is tweak front binding forward if you lose any of your offside

[MattP]

@aupatking Yes, from what I have experienced and talked with Adam about is backward DFT movement from stock is the usual move with this fin. I have not heard of many people going forward with it though. I have tried stock & going forward and it was too unpredictable and squirrelly. I could run up to my average but not consistently. I have heard that people are going a little shorter & deeper as well (-.01-.02 movement of each). So if HO has Short & Deep settings I would start there.

 

I also don't think moving your boots forward is giving you the results you are looking for either. Moving your bindings too far forward will make the tip sensitive and bite sporadically. You more than likely will get slower turns because there is more ski behind your feet. Are you wheeling out of the turn? Slack rope?

 

I would say move the bindings back to stock and get the fin back in it's stock and pull DFT back and give it a shot.

[aupatking]

Thanks @MattP that’s where I went with it last night but didn’t subtract DFT. Will go that way

[AdamCord]

@aupatking This is where the whole "leading edge neutral" theory falls flat. Any time you do that you will massively change the pitch angle and therefore tip height, especially off the 2nd wake and into the buoy. For instance going forward and shorter to keep LE neutral will both be moves that make the tip ride higher. Conversely back and longer will both make the tip ride lower.

 

I'd suggest you pull the fin back to get the stability and tip pressure you're looking for. Especially if you have tons of space, you will benefit from fin back.

[Drago]

⬆️100%

[aupatking]

Thank you @AdamCord that’s exactly what I was feeling off the second wake into the ball. I was trying to add tip but think I had gone further forward than necessary. Felt like a restart was necessary.

[Dano]

@AdamCord in your post above you suggested moving the Autopatkings fin back. Just to be clear were you be suggesting "move fin back and keep LE the same" making the fin longer as well? Or "move fin back and keep the same length"

[AdamCord]

@Dano leading edge position doesn’t matter

[ballsohard]

When will the LFF CG fun become available to purchase again?

[Adam Caldwell]

@Ballsohard - We are expecting a batch this week!

[paul413ski]

@ballsohard what typevifvski

[paul413ski]

Of ski

[ballsohard]

@paul413ski 2018 Radar Vapor Probuild

[paul413ski]

@ballsohard just pm,d you

[ballsohard]

@paul413ski didn't get ur PM

[sfriis]

@AdamCord you write:

For instance going forward and shorter to keep LE neutral will both be moves that make the tip ride higher. Conversely back and longer will both make the tip ride lower.

 

Are you saying that forward move make the tip ride higher?

 

OR are you simply saying that both moves in combination (F.ex. going forward + shorter=> tip high)

 

I always learned that going forward with the fin (stand alone) would make the tip ride lower.

 

btw exited to try your fin - just want to get in shape before changing ski setup

 

[AdamCord]

@sfriis like all ski adjustments....it's complicated.

 

Moving the fin forward will make the tip ride higher in most phases of the course, but it can also make the tip drop lower through the finish of the turn.

 

Here's a way to think about fin moves - Imagine going to the extreme. For instance a fin forward/back extreme would be putting the fin under your front foot or somehow moving it back 10 feet. There is a high pressure zone under the ski where the fin and ski intersect, driving the tail up. By moving the fin forward to under your foot, the leverage that lift has over the ski is reduced, causing the tail to ride lower. Conversely moving that lift point back 10 feet would give it tons of leverage over the ski, making the tail ride higher.

 

Now in the turn when the ski is rotating there are other forces going on. The tail of the ski is sliding somewhat sideways through the turn. The faster/free-er it can slip, the more lift it will generate, and thus the tip will come down through the turn. So a forward fin will cause the tip to drop through the turn. A fin that is 10 feet back will not slip easily, so it will not lift as much, and the tip will stay higher.

 

This effect is why the CG fin has a slot where the fin meets the ski. It reduces some of this pressure, letting the tail ride deeper in the water but still be able to slip and rotate. This is why it is less sensitive to fin moves, and also why it's extremely difficult to blow the tail with a CG fin.

 

It gets more complicated than that when you start talking about drag from the fin surface, fin edges, the holes, the wing, etc. Oh and throw in asymmetrical holes to manipulate that drag on each side independently, and then it starts to get really fun.

[sfriis]

Thanks @AdamCord - I always try adjust the fin to complete my off side turn, getting and holding angle to 1st wake, as good as possible - because thats my weekest spot .... (=> forward will drive tip down through turn)

 

Maybe these new fins will change how we need to think when tuning ....

[BuckeyeBoy]

When will the RFF CG fin become available to purchase?

[AdamCord]

@BuckeyeBoy We just got in a new batch of fins. They are available on the website again.

 

https://www.denaliskis.com/online-store

[sfriis]

@AdamCord sugestions for fin adjustments needed (d3-arc S);

Standard fin were perfekt on 2.467 6.963 0.763 wing 7.5

Tried CG on 2.467 6.963 0.736 (cant go more forward without filing) wing 6

Too much drag - very narrow turns (but not overturning) - I need to work a lot faster and harder

Tried wing 5 and DFT 0.700 (back 0.03) => feel even more drag....

I have an idea that I need to try forward (from 0.736),shorter deeper - 0.015 each (when reading all these posts).

Is it correctly understood?

Your help is very appreciated

[AdamCord]

@sfriis filing on your fin is good for the soul

 

Sounds like you need to get forward of where you started.

[sfriis]

thanks - filed and ready