Fin trailing edge from rail

[4wfs.com]

As an OT aside, I rarely change my fin settings, but was grateful to be able to increase my toe-in when the surf dropped from 4' to 1' in the 4th day of the worlds.  I was able to "fake" full rail turns to progress through the heat and then re-set my fins to surf 6-8' Express Point a couple of days later.

TaylorO: try the more adventurous smaaklik (tasty) on your future trip.  Aply in liberal doses to girls, waves, food and drink.

Well i am stoked that you made an adjustment when u felt u needed it, especially in a competitive situation, where the pressure is even higher to perform. the key is, even tho u rarely change your fin settings, that fact that u could is what 4 ways is really about!

As for Taylor O: Red_boards is right... so i'll give u a sentence to practice in the meantime ( to be used on girls/waves/food/drink)

"Nou, dit is mos Lekker Smaaklik"

have fun!

cheers

Deano

[TaylorO]

ahahahahahahahahahqa!!!

I don’t evn care about the fins anymore… I’m too stoked to get to J-bay and get my

**“Nou, dit is mos Lekker Smaaklik” **On!!!  Ha!

Great info Red -  Did you change the cant as well?  

I’ve been all about increased cant for lift in those small/mushy times, but after adding the extra toe…  It’s a magic combo… I’ve had my mind so blown… I’m not sure where to begin, more fine tuning, different fins, combo’s…  Ha!  Great motivation to get the new shop up and running…

**
**

[reverb]

…hello Obproud,

in a narrow tail fins closer together are fine with manueverability

fins too apart in wider tails is not so good for that.

So your statement about fins closer to middle stringer are stiff is not so clearly.

Multi fins should perform as a whole not alone

depends tremendously on the tail area and the size and position of the surfer foot + the strength on that leg.

That s main big problem for kids and gals that buy rack boards

 

 

[TaylorO]

Good stuff reverb -

That s main big problem for… (I’d say many people.)…that buy rack boards

Individual/customization… It only makes sense to me - I’m the one who rides the way I ride the waves I ride - Anyone would be well served to explore the posibilites…

[red_boards]

@$1

…hello Obproud,

in a narrow tail fins closer together are fine with manueverability

fins too apart in wider tails is not so good for that.

So your statement about fins closer to middle stringer are stiff is not so clearly.

Multi fins should perform as a whole not alone

depends tremendously on the tail area and the size and position of the surfer foot + the strength on that leg.

That s main big problem for kids and gals that buy rack boards

Working through some thoughts here.

The further apart the (thruster) side fins, the better the drive characteristics, yes? (I think I got this from BillBarnfield post a while back)

The reason I mention this is because my boards are extreme.  My side fins are ~8" off the stringer and the boards are ~20" wide at that point.

Now the caveat.  The fins are set at ~18" from tail and the tail fin at ~9" an the tails 16" (at 12’). 

Point being you can pull your fins forward and spread them wider and still retain drive and deal with manoueverability using toe.  Of course, you can’t ride this kneeboard set-up standing up because you just spin it out in cutties, but it will come off the bottom OK.

How does this relate to fins in from rail?  Not sure how it relates to anything.  Just some more (confusing?) data.

TaylorO, I tried more vertical cant once, but felt I was tripping over the fins all the time.  I will try more cant on your advice, thanks.

[obproud]

@$1

…hello Obproud,

in a narrow tail fins closer together are fine with manueverability

fins too apart in wider tails is not so good for that.

So your statement about fins closer to middle stringer are stiff is not so clearly.

Multi fins should perform as a whole not alone

depends tremendously on the tail area and the size and position of the surfer foot + the strength on that leg.

That s main big problem for kids and gals that buy rack boards

 

 

 

Ya, I agree. It is all a balancing act. I was commenting in the context of moving fins around a particular board. If you change the tail width or template things change.

It is not so clear cut as simply putting the fins a certain distance from the rail, especially with quads that have two sets of rail fins. The fins do work as a set, and the template in the tail should define how the fins are aligned. If you have a more curvy tail template then the back fins can be the same distance from the rail as the fronts and not be too aligned. If your tail template is more straight then you have to set the rear fins further in from the rail so that the fins are not too aligned.

In this respect McDing is correct about setting the fins from the centerline, because then the fin setup doesn’t depend on the template.

But… I think that the tail curve should work with the fin cluster, also. So the tail template curve should be desinged with the fin cluster in mind. If that makes sense…?

 

I am kind of heavy with weak legs, so I like a wider board with the fins closer to the rail, because that allows me to put the board on the rail easier. Does that make sense?

[TaylorO]

Hey Red - What do you mean by, “…more vertical cant once, but felt I was tripping over the fins…”

I’m having trouble imagining “tripping” over the fins… Maybe, but not sure - I haven’t tried vertical front fins, but I ride some rear side fins which are 90 degress to the bottom, but there’s at least 4 degrees of vee…

Do you think (If I’m reading you correctly.) you may get more leverage riding on your knee’s which may enable you to have the side fins further in?

ob - “with quads that have two sets of rail fins. The fins do work as a set, and the template in the tail should define how the fins are aligned.” 

What are your thoughts on how the fins are (should be) aligned - Are there certain distances you work with?

[obproud]

@$1

ob - “with quads that have two sets of rail fins. The fins do work as a set, and the template in the tail should define how the fins are aligned.” 

What are your thoughts on how the fins are (should be) aligned - Are there certain distances you work with?

 

I like them aligned like a speeddialer, not too aligned and not too spread apart. I have had some boards with the rears closer to center, but I didn’t like that as much, because it is harder to put the board on its rail. I think for someone with stronger legs it might be better?

 

I made a board with a straighter template in the rail, and put the fins the same distance from the rail, leading to a more aligned pair, and the board lacked responsiveness.

 

In my experience there is definitely a middle ground that is “just right”. And it really depends on how you surf. I think that a guy with stronger legs would want a less aligned cluster, and a weaker guy like me would want a more aligned cluster.

Don’t quote me on any of this though. It is just anecdotal evidence.

[TaylorO]

Ok ob, no quote.  But, it sounds like by “aligned” you mean one in front of the other: true?

What about the distance between the fins - fore/aft?

I didn’t notice as much change in the boards I made with the rear quads at big differences from the rail (2-3"), but when I went to the edge set up (front and rear fins @ 1.25" off rail), based on consulting with Robin “Handshaper” Mair, I experimented with the fore/aft relationship, and was amazed at the changes I felt when the “spread” started to get  beyond 1 3/8" - Went from the smooth feel of the edge quad to the dragy feel of a trifin…  Just my emperical evidence, as you may say…

[red_boards]

@$1

Hey Red - What do you mean by, “…more vertical cant once, but felt I was tripping over the fins…”

I’m having trouble imagining “tripping” over the fins… Maybe, but not sure - I haven’t tried vertical front fins, but I ride some rear side fins which are 90 degress to the bottom, but there’s at least 4 degrees of vee…

I’m enjoying learning here and don’t want to derail the discussion. Just a quick reply:

With the fins vertical I felt that the front 1/3 of my rails wanted to catch all the time.  My thinking is that canted fins help pull the tail down in the water (especially during rail turns) so lift the nose a hair.  My style is the equivalent of a heavy front footed standup - lots of weight forward during turns.

With my full fighting weight of 76kg  I can sink almost any rail because I can apply a lot of that weight through one knee about 4" off the rail. I do notice when the fins are inboard because responsiveness goes down.

[4wfs.com]

[quote="$1"]

With the fins vertical I felt that the front 1/3 of my rails wanted to catch all the time.  My thinking is that canted fins help pull the tail down in the water (especially during rail turns) so lift the nose a hair.  My style is the equivalent of a heavy front footed standup - lots of weight forward during turns.

With my full fighting weight of 76kg  ;-) I can sink almost any rail because I can apply a lot of that weight through one knee about 4" off the rail. I do notice when the fins are inboard because responsiveness goes down.

[/quote]

 

hi Red_boards,

the feeling u had is exactly right, by increasing the splay/can outwards towards the rails u will find the board way easier to respond rail to rail (  ie: easier to sink the rail throug a turn) secondly, the experiences i have had with different boards/shapes etc, have been that, moving the fins closer to the rail WILL increase reponsiveness, whilst moving them inwards towards the stringer gives way more hold and less responsive.

 

the interesting thing here as this discussion has been unfolding is that it becomes obvious that there's no perfect fin-place setting for every surfer, so our individual weights, height, experience, level, waves we ride & riding style all become factors that determine "how a board goes" for each of us...

 

it seems so logical to me , that there is no space left for one single fin-placement to suit everyone.... 

sure there are standard fin placements, that each shaper will use for each style of board they shape that will work, but it's the individual experience of each surfer on each board that determine how good that board is for each surfer, am i right????

 

i find this so interesting, and hence my love for 4 ways ( sorry if it comes across too pushy sometimes) but i believe in it and what it can do for each surfboard/surfer.

 

the hardest thing probably is figuring how much change is needed for each surfer, but it seems that it's just "little-subtle" changes that can make the most differences to our experiences on each board we ride.

 

Best regards to all,

 

Dean

 

[TaylorO]

Good stuff you guys - Dean, I couldn’t agree more.

Red - I’m trying to get my head around your experience - my understanding/experience with additional cant is more lift, as the foiled side of the fin lifts/pulls into the flow of the water, helping facilitate the turn, the higher angle of cant will want to lift up more…  I have not tried vertical side fins (And after your experience I probably won’t… Ha!), but from what you wrote my thoughts are:  The lack of can’t may want to make the board pivot flatter in the water, where the more can’t the more lift on the whole board, and into the turn, so you are use to being able to lean into your turn against some lift, where as the lack of lift with the vertical fins caused you to feel like you were “tripping” over the board as it was turning flatter…

Thoughts anyone?

[4wfs.com]

Taylor,

the "feel" is simple, if the board is wide or thick, it's always harder to "sink" the rail

 

therein lies the subtlties in shape that require changes in cant/splay...sometimes... not always, but in this case yes!

 

remember tho too, for every positive change , u create a negative reaction elsewhere, hence in the case of RED_boards above, increasing splay outwards towards the rail will help get him to sink the rail quicker and allow for the rail to rail transition that he is looking for without feeling like he is "falling" over his board because he has to push so hard.

 

so by increasing splay, u get the positive of rail to rail transiton and response, but u start to loose drive and speed due to the increase in drag created.

 

with 4 ways, i designed the system to be able to negate the negative effects of increase drag, by being able to simultaneously toe the fins out if need be when the this feeling was experienced.

 

Again, the thing to be clear here is:

1) each board shaped is unique and there are subtle differenes in each and every surfboard produced,

2) each surfer is different, and evolving all the time,

 

so having the option to  to be able adjust when needed is the critical element, in my opinion

 

hope this helps?

 

Regards

deano

 

 

 

 

[TaylorO]

Thanks Deano - I am with you 100%

So many options, and, lately, so few good waves to test on… Ha!

Any news on the inserts?

[4wfs.com]

hi Taylor,

i had my meeting with Adam this week and i gave him a bunch of new discs that he will bring home with him, just for you!

 

he should be back at work around the end of the month ok...

 

regards

Deano

 

[TaylorO]

Sounds good Deano - Should expect I Maike to be out of the equation now?  Would you please make sure who ever is sending contacts me first, as I’d like to order a couple of things as  well.

Thanks again Dean - Still feeling the magic…

[f1f859bda2f2a3ab344c]

@$1

hi Red_boards,

yes, u are correct, as u rotate the fins inwards ( more toe-in), the trailing edge of the fin does move towards the rail.

 

This  is a complimentary action as the idea behind toe-ing in is to increase turning ability, so by having the trailing edge move 1mm closer to the rail the board will respond quicker by complimenting the action of “toe-in”.

 

Conversely, if u were to “toe-out” away from the stringer for a more “faster” more “stable” feel, the action of the trailing edge inwards towards the stringer provides the hold along with the speed.

 

hope this helps?

regards

Dean

 

 

 

 

Hi Dean…

If I may take this concept in a polar direction…

Most of my “surboard style” kiteboard builder freinds, as well as myself, are realizing that too much, or should I say “normal surfboard” toe is not beneficial when traveling at higher kite driven speeds in smaller wind driven waves…

Toe in’s of 1/8" to 3/16" max. are starting to be more common than the accepted 1/4" when measured at the fin base chord…

If a kite surfer rides  much larger/powerful traditional waves, with a very small kite,   more traditional toe  seems to be  prefered…

But I’m sure you’re well versed in this…

Too much toe when being dragged around  by a kite results in too much drag…

A far as trailing edge fin placement of a quad set on a typical kiteboard,   1 1/8" to 1 1/4" fronts   and  1 1/2"  rears  off  the rail seems to work very well for me… Mileage may vary…

With your system, you could tune the toe-in  as well as rail proximity to the windspeed as well as wave power… An interesting concept…

[MrJ]

I have enjoyed in particular the last 2 pages of information exchange on this
thread. It shows how type of board and other aspects of fin position all have to
be considered as a whole along with trailing edge from rail measurement.

A mate of mine likes to challenge his surfing reasonably regularly with a
different shape. He is a good surfer but not a design enthusiast and takes wild
guesses as to what might work for him. This is good for me coz I get to borrow
and measure his boards.

Here are three thick boards. The one on the left is mine. From left to right
6’ 3" x 2 1/2" thick Pancho Sullivan" by Bushman. 6’ 2" x 2 5/8" thick “The One”
by Webber and 6’ 1" x 3" !! thick Nugget by McCoy.

[img_assist|nid=1058351|title=Three thick boards|desc=|link=none|align=left|width=640|height=480]

A favourite tactic of mine is to ride high on a walled but gently sloping
section of a wave face to beat a section. The point break waves which I favour
in Vicco tend to encourage me to do this - can hold lots of water, but not be
hollow - in this situation I find that the steepness and speed is at the top.
Maybe this is lazy surfing and I should learn to surf top to bottom in all types
of surf, but thats how I frequently do it and like it. Its therefore quite
important that my boards need to have quite good fin holding power.

The McCoy Nugget on the right holds in quite badly high up on a section. I
put this down to its massive thickness and very chunky rails, which are thick
and rounded right into the front fin region.

The Pancho Sullivan holds in exceptionally well despite having tall boxy
rails in the front fin region, but its narrower and the rails up front are
considerably thinner than McCoy up front. I wonder if thick boxy holds in better
than thick rounded by having a top release edge? but this is pure
speculation.

However I took “The One” by Webber out into some fairly solid but gently
sloping and bumpy point break and it span out on me most unexpectedly when
trying to beat a section. From looking at its narrower tail I would have thought
it would have held in at least as well as my Pancho board. So my initial theory
for why it doesn’t hold in so well is in the pic below. As can be seen in my theoretical picture the fin gets a better bite in the curvy tail.

Taking a look at the 3 boards pic above it can be seen that the Webber tail is very much in the straight hip category like the conceptual board shown in the diagram below.

 [img_assist|nid=1058443|title=Effect of tail curve on penetration into a steep wave face|desc=|link=none|align=left|width=640|height=462]

[MrJ]

@$1

… my initial theory
for why it doesn’t hold in so well is in the pic below. As can be seen in my theoretical picture the fin gets a better bite in the curvy tail.

Taking a look at the 3 boards pic above it can be seen that the Webber tail is very much in the straight hip category like the conceptual board shown in the diagram below.

 …

However, I wasn’t convinced this was the reason or the sole reason. So I decided to take a look at the fins and measure them. The diagrams below explain my next theory.

[img_assist|nid=1058441|title=conceptual fin bite of the "Pancho Sullivan" by Bushman|desc=|link=none|align=left|width=640|height=462]

[img_assist|nid=1058440|title=Conceptual Fin bite of the One by Webber|desc=|link=none|align=left|width=640|height=462]

[MrJ]

In addition to the cant situation above the One Fins are slightly further in from the rail which I think contributes to less hold.

However taking a look at the Nugget fins in the pic below, the cant situation is really quite favourable placing its fin tips closest to the rail of the three boards, but it holds in the worst. So in this situation I think the bloated rails is the overriding force. Just goes to show how difficult it is to look at isolated design features!

[img_assist|nid=1058442|title=Conceptual Fin bite of the "Nugget" by McCoy|desc=|link=none|align=left|width=640|height=462]