Fin Settings - Personal Standard?

[ToddL]

I am wondering if top level skiers who always log their fin settings have noticed a trend in their preferred fin settings vs stock settings as the move from one ski to the next ski. What I mean is: have they noticed that their final/preferred settings are always 0.xxx +/- from stock? The hypothesis is that a skier likely ends up a similar amount away from stock when they setup a new ski for themselves.

 

Skier "A" might always like a little bit longer fin and ends up with length always +0.100 above stock on every ski.

Skier "B" might always like a little shallower fin and ends up with depth that is always -0.050 below stock on every ski.

And so on... I suspect the same question might apply to binding positions.

 

Any fin tweakers out there ever study their logs to see if there is a trend?

 

Also, if so, did you apply those personal preferences to any after market fins (Whisper Fin / CG Fin), and find the same to be true?

 

Maybe every ski requires a unique setting, but I just wonder if personal preference results in trends for an individual.

 

(PS: I keep crappy paper logs of settings. I wish I had started a spreadsheet.)

[PatM]

Rossi mentioned something in his podcast about roundabout settings that he goes to when starting off with a new ski

[Horton]

@ToddL would you season every cut of meat the same?

[BraceMaker]

When someone is measuring to a thousandth with a caliper that is a +/- .001 accuracy but then lists a fin measurement to les than a round 5 thousandth I get suspicious.

 

That’s said you should be closer than a ten thousandths for sure in any world. But a 6.883 to me is a 6.885 or a 6.880 between two people measuring that’s not a reliable difference.

[Horton]

@ToddL

 

"Stock" is a setting designed by the team at each factory. So all "Stock" settings are NOT based on the same targets or methods. There is not universal standard.

 

Fin settings change the pitch/yaw/roll (& drag & slip & other stuff) of a ski. Every ski rides in the water differently so there is a different starting place with each ski. This is why some skis work better with short/deep and some work better with long/shallow.

 

In other words this is a false premise.

 

On the other hand a lot of upper level skiers know when they get lost they can always go to the "Master Settings" or "Mapple Settings" 6.850 / 2.500 / .770 (+/-) If a ski sucks with these settings it is time to wonder if something else is going on.

 

 

[thager]

@ToddL The only fin setting consistent for me over the years has been length. Whatever the stock setting I end up adding about .017-.020 in length when I am done tuning. DFT and depth are all over the place depending on the ski. Only exception was the Denali C-65 and I just couldn't figure that tune out at all.

[ToddL]

I expected a lot of criticism on the premise. I still wondered about it. Worth the dialog IMHO. I have been skiing Radar since 2011. So, maybe my view of this is skewed by that consistency of the test team driving the "stock" settings. I imagine that other brand loyal skiers have also found some consistency regarding stock settings within their brand.

[ToddL]

@Horton - a lot of meats taste really good with just salt and pepper. (...if you buy decent cuts.)

[Horton]

@ToddL would you use the same amount of Salt and Pepper on a single New York Strip as you would on a Brisket?

[Horton]

@ToddL If you are talking about within only one brand of skis then yes your idea sort of holds water but that is only really true if the designer is very conservative and does not innovate.

[keithh2oskier]

@Horton @ToddL

[Anderson]

@keithh2oskier - Setting aside the esoteric black magic of fin settings for a minute, any BOS member who can combine Letterkenny and skiing makes me smile :-)

[Luzz]

@ToddL Interesting question, but I'll provide a slightly different answer. What I have noticed is that I always end up using a bit more surface area than most recommended stock settings in the industry. Doesn't matter if I go 6.83x 2.52x or 7.01x 2.44x… to me, the first variable I look at is surface area, even through the super rough LxD calculation. Now, keep in mind that the vast majority of my tests are on HO skis, but the occasional times that I test skis from other brands for my own curiosity, I seem to always add fin.

 

This makes a lot of sense to me. Someone who is trying to run 41off SHOULDN'T have the same surface area as someone trying to run 22off (and, even more importantly, not on the same ski, but that's for another threat). And very few skiers who are buying skis are trying to run 41off.

 

In terms of DFT, no consistent pattern for me, except that for whatever reason, I find myself being around .005 to .015 further forward than a long-shallow "stock" and .005 to .015 back than a short-deep "stock".

 

:expressionless:

[santangelo]

Reiterating some of the above, but I've learned within the same manufacturer, my settings work well on all of their ski's. I tend to ride oversized ski's so my set-up is far from factory, but it does work well.

 

About 900 ski's in the database now...use this to track your settings.

 

finDB for IOS

finDB for Android

 

I'm putting together a new release and may include a spreadsheet export if it's a desired feature.

[bigtex2011]

@ToddL i seem to have the same surface area from ski to ski. it has worked for me on all radars since 2013, several d3's and the KD Platinum.

 

for me 17.06 seems to work. i'm currently 2.455, 6.950. If i get in a slump or water temps change i go to 2.490, 6.850 or 2.480, 6.880

 

this has worked for me, hopefully it will work for others

[ToddL]

So, two skiers have commented that they have discovered a preferred surface area which then can be applied to length & depth configurations. Now, my mind is wondering this...

 

Assuming most stock fins use a common leading edge curve profile, this concept is sufficiently stable for those skiers. What about the CG fin and Whisper fin? Has anyone considered a surface area factor comparison? For example, if @bigtex2011 have found that surface area of 17.06 is his sweet spot, then what would his CG fin sweet spot be? What would his Whisper Fin sweet spot be? Does this even matter? IDK.

[BobF]

Since fin surface area is, at best, an arbitrary number, I think it would hard to apply the differences to the non-conventional fin shapes. Length x Depth gives us a pretty standard way to determine how much fin you like in the water, but it's not actual area. Assuming that someone who likes a lot of fin overall may need even more if it's a "pointy shape" is fair, but I can't imagine a way to accurately figure out how much.

(tldr - I don't math enough to figure it out)

[MattP]

See this thread: https://www.ballofspray.com/forum#/discussion/18935/fin-surface-area-equation

@tap did the math

Surface Area = (2.697 * Length) + (4.841 * Depth) - 18.924

[bigtex2011]

@ToddL probably 1 thing i should mention. I use the same fin on every ski. It's a radar/mapple 5 hole.

[BobF]

@MattP, That's a great thread. Interesting stuff, indeed.

[Horton]

I often accuse @AdamCord of using a random number generator for fin settings. He sent me some completely bonkers numbers the other day. Oddly enough they feel pretty good.

[tap]

Yep, did the math. Fun exercise if you're really really borred. Had to digitize a fin into CAD to get the raw data. It was a Radar fin if I remember correctly. The resulting equation is quite accurate. Never got around to doing it for a CG fin.

 

For what it's worth, i don't use the math, i did it more as a sensitivity study to see how depth and length effect surface area. As you can see in the equation, you pick up quite a bit more surface area for every thou of depth than you do for every thou length. It is definitely not a 1 for 1 relationship.

 

Fortunately for me I figured out several years ago that all I have to do is call up @AdamCord and ask him what he's running, then i pull about .020 of depth out and take off a degree of wing and that usually works pretty darn well. Basically i let him do all the voodoo then just free up the ski a bit... I don't pull as hard. I'll tweak a bit from there, but he puts me in the ballpark. It helps if you're riding a ski that is very forgiving to setup.

[Luzz]

@tap would you say that would work better for other similar although not the same fins? HO, Connelly, D3, Goode, etc…

 

btw, thank you @MattP … I have been looking for this forever :astonished:

[tap]

@Luzz if the shapes are similar, which i think they mostly are, then yea it should be fairly decent. Certainly going to be way closer than the overly crude L x W or 1/2 x L x W approximation. My guess is the difference will mostly be in the offset. I would think the sensitivity of how depth vs length adjustments effect surface area would be pretty good for any fin of similar profile.