Conversation with Adam Cord 4/3/16

[Horton]

Adam: So how you skiing

Horton: meh. Ok but not as wide and early as I want

Adam: Take some fin away. Take out depth and length.

Horton: No I am just not as centered as I should be. It is not the ski

Adam: Just take out some depth

Horton: No Adam. It is not the ski. I need to work on me

Adam: You should really adjust your fin. I am sure the problem is not your skiing

Horton: Very funny. No. I am working on my gate and being centered. I also want to carry more speed out of On Side. I need to be more smooth

Adam: Why don’t you put a washer under your fin block on your On Side to smooth that out.

Horton: Darn that sounds like fun…. Ok I will do it.

 

[Horton]

So I DID NOT measure anything. I unscrewed my fin block, slid small washer under the middle screw hole on the left side of the fin block and screwed everything back down. The result was not wild different but I have to say my On Side turns were a lot more flowing. It was the best ride so far this year. I shortened to 35 for only the 3rd time since my injury and ran 3 in a row.

 

This concept is for sure interesting.

[Bruce_Butterfield]

The next step is to keep the washer on the left and put another one, twice as thick, under the front screw on the right side. That will make your offside just as flowy as the inside. I was flat amazed at the effect. Subtle, but definitely an improvement.

[Horton]

@Bruce_Butterfield please please please tell me you think it's till April 1st. You're joking right?

[Adam Caldwell]

Starts to make you think about all those skis you can only tune to be good on one side or the other.... Very likely there was a miss-allocation of fin area that was NOT working in your favor, no matter what D/L/DFT adjustments were made.

 

[Bruce_Butterfield]

@horton, no it's April 4th. We are just starting to experiment with this, so I probably shouldn't have mentioned it yet. You just need to think about how the fin dynamics affect each side differently and it will make sense.

 

Why does LE have a dominant effect on the offside while D and DFT have a dominant effect on the onside? It's a very similar phenomenon.

 

The washer in the middle on the left is effectively changing D only on the onside while leaving D unchanged for the offside. The thicker wash on the front on the right is effectively changing LE only on the offside.

[Horton]

@Bruce_Butterfield I hear you but I am going to try to forget we ever had this conversation.

[Adam Caldwell]

@Bruce_Butterfield, for me personally, I've not needed to consider the length adjustment on the opposite side. As the ski is deflected below the middle of the fin block, you are getting a reduction of surface area over the entire length of the fin, not only at the deepest part of the fin where we measure. Its deflection will be at a maximum where the jacking screw is located, and at a minimum at the ends of the fin slot. Area reduction is not isolated to where we measure depth only.

 

Taking that into consideration, adjusting the length with washers on opposite side doesn't seem necessary, and to be done effectively, would require running a longer fin slot to get deflection under the front screw, which then starts to impact torsional stiffness, which could be good, or bad.

 

Using the Denali Fin Area Tuning system simplifies life tremendously. Dial in the settings for a stong toe-side turn, and then crank down on the set screw to reduce overall area on the heel-side turn comes alive.

 

Since @AdamCord and I ride a new ski nearly every set, and constantly playing with settings, we run a thumb screw installed so its possible to reach down at the end of a pass and make moves on the fly.

 

Most of us consistently run 20-30K delta between depth measurements side to side.

[AdamCord]

For anyone who wants to try this (you should!),

 

Left foot forward skiers put the washer on the right, Right foot forward skiers put the washer on the left. This image is from a Left Foot Forward skier:

 

 

This is something that can make ANY ski work better. Do skis absolutely need it? No, but it will make the turns more balanced. We have gone as far as a .040" depth offset from deep side to shallow side, and it was pretty good. It's hard to get much more than that because the ski will only flex so far.

 

How to use it to tune a ski:

 

If your offside turn is pretty good, but your onside turn leaves something to be desired (if it feels like you have to be in just the right spot or you'll wheelie, get dumped, get slack line, etc.) then you need to just install the washer and leave everything else the same. This will leave your offside turn the same, but the ski will rotate more freely on your onside.

 

If your onside turn is pretty good, but your offside turn leaves something to be desired (your offside turn feels unstable, bitey, sensitive, or just isn't what you want) then you need to install the washer, then add depth so that the washer side is the same as it was minus about .005". That means if your previous depth was 2.500", your new depths with the washer will be 2.495" shallow side, and 2.520 deep side (assuming a .025" offset).

 

If both sides could be better but are already fairly balanced, add the washer and then split the difference with the depth.

 

[ktm300]

Sho nuff my onside was deeper than the off by 5. I have never even thought about this. I put the smallest washer I had in and got a 15/1000 reduction in depth onside. How shallow an onside are you finding is acceptable? Before the washer my depth was 2.450 (shallow by traditional notions) Now 2.435 (I have never had a fin this shallow) I want to try the idea but I don't have time to re-invent the wheel. Please give some guidance as to the acceptable ranges. Thanks!!

[AdamCord]

@ktm300 there's no issue with 2.435. I have gone as far as 2.410 on the shallow side when playing with long/shallow settings.

[Than_Bogan]

Although I am a current @AdamCord disciple, for safety purposes I feel I should point that just because he has gone somewhere does not necessarily mean you should... :)

[Wish]

Yeeup.. A washer convert. How nobody thought of this before is beyond me. Smart guys those Adams...and that's just with a washer.

[rfa]

Just curious...is that section of the ski sufficiently "elastic" so that it will not deform once/if the washer comes off. Thank you

[Adam Caldwell]

@rfa A ski is basically a big leaf spring. Its fine to push it 20-40/1000s over a 6" span. No need to go beyond that.

[gmut]

Well back in the day Andy used washers under the screws of his fixed fins to change the performance characteristics of his skis.

[Wish]

@gmut i think a lot of us did that but it was usually to change the fin equally on both sides in terms of changing depth and length and little else. Until the Adams, I'm not sure anyone has tried to change the surface area differently on each side of the fin. Even D3s Rocker Block displaced both sides equally.

[ALPJr]

I would be shocked if it hadn't been done in some ways before. BLP, KLP Mapple, Syderhoud, Roberge etc...with bigger purses on the line back in the day some of the old secrets may never be known.

[ToddL]

News Flash! Home Depot and Lowes report a nationwide shortage of stainless steel washers.

[ToddL]

@Wish - I wonder if a D3 Rocker Block half can be mated with a D3 standard block half. Hmm...

[skibug]

So, what is the washer thickness you are using? Is it a fender washer to allow for some surface area?

[Stathis Ventouris]

@AdamCord I am a RFF and my fin is deeper by 35thous. on the left side. If use a washer under the middle screw of the fin box at the left side of the ski as recommended for RFF skiers, both sides will probably get even. Therefore should I use a thicker washer?

[AdamCord]

@Stathis Ventouris You can stack up 2 washers if needed. I'm not sure you'll be able to get a big offset where the left side is much shallower, but just evening out the two sides will be a big improvement.

[Stathis Ventouris]

@AdamCord thanks, will try the coming weekend and report back.

 

[Horton]

If this becomes a common practice @AdamCord will get credit but he may not have really invented the idea. I understand Wade Cox may have done this sort of thing 20 years ago*. I had never heard about it until Adam told me ... I guess the idea had been somewhat lost over the years.

 

*there are conflicting reports about if Cox used a washer to shallow the whole fin or change the depth on one side. IDK

[AdamCord]

@Horton I wouldn't be surprised if he had done this. Wade is a smart guy and this is a simple idea. When it occurred to me I couldn't believe I had never heard of it before.

[ToddL]

An innocent question...Does this ever so slightly cause the fin block to become slightly out of perpendicular to the ski's surface making the fin no longer at a 90 degree angle from the bottom of the ski?

[skialex]

@Stathis Ventouris loosen the fin clamp's screws, use spacers in the fin slot to center the fin, then tighten the screws again, loosen and tighten the fin, measure both sides and everything else and you might be ok and with an even depth on both sides.

Then put the washer B)

[skibug]

What is the washer thickness that is being used? I am also curious about the answer to the question above...doesn't it make the fin not 90 degrees to the bottom of the ski?

[Horton]

Pretty sure my fin is 90°

nothing to worry about

[Wish]

It does not displace the fin out of 90 degrees to the bottom of the ski..or whatever it was before the washer. The ski is the weak link and gets the displacement to the side the washer is located. Thickness has not really been an established thing as far as I know..just go grab a washer and give it a rip.

[Adam Caldwell]

@skibug

If you put the washer at the front or rear mounting holes it would act to put the fin on angle. If the Front and rear screws are mounted flush to the ski, and a washer installed beneath the middle screw, the ski will deflect beneath it, and not "tilt" the fin at all. As @Wish stated, the ski is the weak link, and will deflect below the aluminum block. The washer thickness, and or diameter will govern the changes in depth measurement for a given side.

 

Rule of thumb, the deep side should remain the same as what your currently running until you determine there is a need to make more changes to fin setup. Just let the shallow side be what it is, play with washer thicknesses or, get more fancy and drill/tap the hole and drive a thumb screw into it for limitless adjustability on the fly.

[skibug]

@Wish and @adamhcaldwell

 

Thanks for clearing that up.

[mwetskier]

@adamhcaldwell - assuming one chooses the route of installing an adjustment screw do you put some sort of metal shim down to prevent damaging the ski surface?

[mwfillmore]

Don't think I need to try this... But I have to try this. I love the Adams and their ideas

[eleeski]

Flex matters. If you want to make it interesting, use rubber washers. I did this under all the screws when I was using stiffer fins. I noticed and liked the feel.

 

One other aspect may be to add a bit of hook to the tail. The washer does this a bit. I can't remember who told me to try it - adding a bondo hook to the tail really helped. I never purposely mismatched the bondo by the sides but it was a very easy tune.

 

The washer tune is very clever. But don't try to do too much - the screws holding power is limited.

 

Eric

[skialex]

@mwetskier, I thought of installing a screw after seeing Denali's pictures. Your thought of a shim needed is great, you can make room for the shim on the bottom of the fin block so at neutral it would not act as a washer.

[Razorskier1]

I've skied with Wade several times. What's funny about it is when he adjusts someone's ski. He didn't measure a thing. Grabbed the ski and bumped it a little in whatever direction he thought it needed, tightened it back up and handed it back. His comment about skiing back in the day -- "nothing Andy or I skied on was stock".

[rq0013]

While this is a cool idea, it's been done for years. I know a few pros that tried this years ago and they had seen it done before them. It's just now getting to the public

[Wish]

@rq0013 start namn names..haha.

[Adam Caldwell]

@mwetskier, if your ski has inserts below the fin block, then the larger screw size would be driving against the insert directly. Alternatively, if it doesn't, then it wouldn't hurt to put a shim of some kind for the screw to Jack against. @ Skialex makes a great suggestion that you could make a relief in the bottom of the fin block such that a shim under the jacking screw could be neutral (no offset) and would give you something to run the jack screw against if the ski did not have inserts.

 

 

[Adam Caldwell]

This is from before the Denali Fin blocks were finished, showing an example of how a standard fin block could be modified.

 

 

[mwetskier]

i will have to look in storage but i think my mapple ski only has 4 fin block screws os it looks like a relief cut in the block and a stainless shim is in order. on a side note the 'urban dictionary' thinks a shim is something different than i do.

[Ed_Johnson]

The Mapple Fin Block does only have 4 screws, no center screws. I plan to use some small strips of Gorilla Tape on the center side to build up the thickness and see how well that works.

 

 

[Horton]

@Ed_Johnson you can still use the washer. Pop the fin block off & put down a washer or some other shim and then maybe a little piece of tape just to keep it in place when you are tightening everything down. As long as the four screws are super snug you should be fine

[Stathis Ventouris]

@skialex I will follow your advice...

[skibug]

You can actually see the deflection of the ski, under the thumb screw, in that picture.

[mwetskier]

to err on the side of caution i would suggest you use a large padded c-clamp or similar to pull the block flush to the surface and then install the screws. that will avoid any undue thread load or wear trying to pull the block down with just the screws alone.

[Adam Caldwell]

Who's been out to try it?

 

[LeonL]

Just to raise a question....the thumb screw would be good for testing, but wouldn't it be illegal to use in tournaments? Do I remember the rule correctly? 8.03.c(2) is a bit unclear. Does "during actual skiing" mean while the skier is moving over the water or does it mean anytime the skier is in the water during a round?