D3 adopts a new thinner fin as their standard

[SkiJay]

While setting up my new Helix yesterday, I noticed the fin that came with the new ski is different from the fin on the pre-production Helix I was testing. The fin on the pre-production ski was the same old tried-and-true Swiss cheese fin D3 has been using for years. The new fin is exactly the same shape with the same five hole pattern, but now it only has a single set of wing mounting holes. The wing still mounts in exactly the same location as it did in the previous fin's stock holes.

 

 

With the old fin laid over top of the new fin, it's easy to see that the profile and five pressure relief holes remain unchanged.

 

Not only are there three fewer wing-option holes, the new fin is .009" thinner too. At .087" thick, it has been slimmed down from .096" thick. I called D3 to learn what they were after with these changes. It turned out that the change had more to do with production considerations than performance changes. D3 intends to use the new fin throughout their product line, not just on the Helix.

 

It only took one ride to notice that the new fin needed to be shallower than where I was with the old fin. If your new D3 has a fin with only one wing location on it, you might find that shallower livens up the turns a tad without getting too loose.

[Horton]

Thinner find should mean the ski is faster and "maybe" rides deeper

[schroed]

Interesting post. Thanks for the info.

[Wish]

@MrMS and @MS are ya listnin...

[The_MS]

@Wish She has the thin fin but she has not been on the ski yet. Probably this weekend.

[Wish]

@MS just making sure you saw that case ya wanna adjust it. VERY cool that she wants to get on it with water temps that low. How the hell did you get that lucky and she got so screwed?? ;-)

[ForrestGump]

I was at @MS 's place last night. F me, it's cold up there!!! I can't imagine anyone skiing.

[SkiJay]

It turns out that D3's Helix test team has been finding the magic not only at shallow settings but at shallow, long, and forward settings. Paul Crawford recommended the following numbers as being worth trying for the 66". They are a significant departure from the initial factory settings so I tried them today with a little trepidation, but I LOVED them so much I have to spread the word:

 

FL = 6.940" (tips)

FD = 2.488"

DFT = .755 (head)

Wg = 7°

Bf = 29.125"

RockerBlock = R-30

 

This is with double binding plates bolted firmly to the ski. D3 skis are laid up to flex properly with double fixed plates. Velcro and floating Sequence plates allow the ski to flex more than bolted down plates, so tune accordingly. I had a floating Sequence plate mounted in the beginning and ended up at 6.904, 2.511, and .740 to compensate for the extra flex. The difference between these numbers is huge, so consider what kind of binding plates you are using and how you are fastening them to the ski when choosing your initial setup.

 

I'll be sticking with the double plates (Radar Strada) on this ski as I found the ski way more consistent than when it had the floating Sequence plate on it. With the Sequence's extra flex, I occasionally got too much tip pressure when I loaded the ski more than usual at the ball. With the solidly mounted bindings, the ski hasn't surprised me in a bad way once yet. It's fast, stable, forgiving, and turns like mad. It's perfect =)

 

No I'm not sponsored by D3 in any way—just really impressed.

[The_MS]

@Wish She is a great driver to.

[ral]

I am long but not that long, 6,926. But not that shallow. @SkiJay‌ , what specific effect have you noticed going that shallow?

[SkiJay]

@‌ral Mostly, I've noticed that the ski rolls up onto a steeper edge easier.

[SkiJay]

Thinking more about @ral's question, I was also expecting that the tail would be a bit loose at the finish of the turn, but I haven't noticed any of that yet. Probably because the extreme fin shallowness is matched by equally extreme fin length. The fin area itself has remained fairly normal compared to other skis. In fact it's slightly on the high side of average. D3's have traditionally had the highest fin areas in the industry, but that's probably going to change now that they've removed the extra holes from the fin. Just eyeballing it, the three fin placement holes that have been removed about equal a sixth hole in the fin, and the number of holes isn't factored into most measures of fin area.

[webbdawg99]

I'm surprised that I didn't notice the new fin on my Quest. I asked Paul if he had any suggested numbers and he told me to stick with the settings off my old Quest. After reading this, I'm thinking that may not be the best idea.

 

Im running mid 38 at 58k. My settings are currently

6.925

.760 slot

2.500

7 degrees

 

Anyone have an opinion on these numbers and possible "improved" numbers that reflect the new fin?

[SkiJay]

FWIW, @webbdawg99‌, the Helix is still a new ski and the numbers are still not cast in stone. The Quest is a proven design. If Paul says the new fin works with the old Quest numbers, it must be so, or pretty darn close. If you are really curious, try .003" - .005" shallower and the same amount further forward from your last personal numbers. You'll either like it better or not. What length is your ski btw?

 

Drawing conclusions from my experience described above is screwed up by too many changes all at once. I made major changes to the fin placement, ski flex (binding plates), and binding position all at once--not to mention the ski itself (pre-production to production) and old fin design to new fin design. It was a total leap of faith guided by Paul's knowledgeable advice.

[webbdawg99]

@SkiJay, I'm on a 68. Correct me if I'm wrong here, but with the same fin measurements that I was running on my old ski, won't I be running more surface area simply because of the fewer holes? Surely this would have some impact on fin performance. I have noticed of felt like I wasn't getting as good of a "smear" at the end of my turns. I'm definitely thinking about shallowing it up a hair....just as you've described. I'll probably wait until it warms enough that I can ski more consistently and accurately evaluate the impact of the change. Thanks for the insight!!

[SkiJay]

I think you're right @webbdawg99‌. I suspect that the difference is small enough that most skiers will ski right through the change without noticing it, but that to consistent and aware skiers who ski a lot, the change is noticeable. You're also wise to be suspicious of the effects of cold water which include reduced smear.

 

I'm curious enough that today, I'm going to put the old fin in my new ski, keeping everything else constant, to see just how noticeable this change is—or isn't. Today's weather is even unchanged from yesterday's.

[SkiJay]

@webbdawg99‌ Today I put the old Swiss cheese D3 fin on my new Helix with exactly the same settings as the new fin, and changed nothing else. I shadowed the course at -35 for the first couple of passes, starting narrow then amping it up to full course width just in case there were any lurking surprises. There were none. In fact I couldn't tell any difference in the ski at all. Hmmmmm . . .

 

I then lengthened the rope to -32 and moved into the course. I then missed one ball three times straight, each time due to less tail support than I was expecting. Granted it was a strong tail wind on all three, but it was a stiff wind yesterday too, and I wasn't having this issue. Then I adapted and ran the pass. It didn't take long before it was no longer an issue except for traces of over-turning and small wheelies when I wasn't in good position. If I was going to keep using the old fin, I'd add .003" of depth and possibly decrease DFT by .003". On the other hand, if I left it alone, I'd fully adapt within a couple more sets.

 

I suspect that most skiers won't notice any difference at all; but a consistent and aware daily skier may. It's certainly close enough that using your previous favorite numbers will work fine for anyone not interested in fin fiddling. If you'd rather fine tune the ski than your technique, then try setting the new fin .003" shallower and maybe a hair further forward than where you had your old fin. For most, the new fin will come on a new ski which may require slightly different numbers than the old ski anyway.

 

Factory listed setups are intended to be a solid starting point. From there you can chose to either adapt your skiing to the factory setup, or to adapt the factory setup to your skiing. After today's experiment, I'd have to say that these two fins are close enough to be immaterial in that choice.

[webbdawg99]

@SkiJay Awesome intel. I think I'll leave it where its at. I'll only make adjustments as I normally would. Thanks so much for the research!

[SkiJay]

You're welcome @webbdawg99. My pleasure.