The Fin Thread

[dklavoie]

Lots of great info on fins in the Zone, but man is it spread all over the place. Thought it might be useful to get many of these great opinions on fins in one thread. Would love to know what fins ya'll are using on what boards, characteristics of the board (box placement, bottom shape, tail, rail, etc), in what conditions (technical races in chop, coastal crusing, downwinding, surf, pure speed, etc), to ventral fin or not, stability versus speed versus agility, keel/dolphin/hatchet shaped/foil?, and other factors that currently escape me. And while these are all just personal opinions, it sure would be helpful to give other zoners a place to start when on the hunt for the "perfect" fin. Cheers.
d

[burchas]

IMO one thread is not suitable for such a diverse subject. Realistically you'd want
a forum category covering the subject, and while at that, have 1 sub category, sup surf fins.

But that's for Admin to decide if there is enough interest and logic.

Personally I think there is. As you pointed out, the amount of data on the zone about fins is out
of control and you'll get lost pretty fast trying to sort thing out your self.

If you want an example of how fast it can go sideways take a look at that thread:
https://www.standupzone.com/forum/index.php/topic,22706.0.html

Even-though it's a narrow subject, see how long it will take you to sort it out.

[Luc Benac]

The more I try fins, the less I am sure of any absolute truth....
general comments are:
for a narrow race board 24" and under, Larry's four fins set is  a great solution and you can alternate between twins and single with ventral.
for all-water boards like a Vapor and so on, often a smaller fin might work better
for dug-out the semi-dolphin shape of the Mako seems to work really good for choppy but sometime a longish sweep fin works nicely for flat
for downwind, get a downwind fin and try all the different shape to find the one(S) you like
for catching small surf at the beach, dolphin shape seems tried and true

The smaller the fin, the more effect it seems to make to change position on the box
In many boards a small ventral fin is a blessing for side chop, side wind. The Vapor and the Ace-GT do not seems to need one.

Finally, like everything, it seems to change as much as the weather and what you like will come and go and come back so do not throw away a fin, you might very likely love it in a few months and hate it again and again....

[dklavoie]

Yeah you're right Burchas, a tad ambitious. Wow 19 pages for that thread. Sheesh! That's some great info Luc. Cheers
d

[Beasho]

Ahhhhh Fins. . . . So many opinions, so little data.

I started a fin thread a while back, didn't get very far.

https://www.standupzone.com/forum/index.php/topic,30992.msg339357.html#msg339357 

I have been focused on fins increasing the performance, being fast and turny, while surfing waves as they get bigger.  My conclusion: Go smaller as the waves get bigger.  Drag increases as the square of velocity.  Use the smallest fins that will allow you to turn in combination with the boards rocker without spinning out.  Any bigger and you are dragging around little anchors with every stroke.   

This video does a great job to show the fins working on an inclined plane.  Similar to  traversing a moving river from one bank to the other while holding a rope or getting towed behind a boat.

[coldsup]

For surfing folks seem to reckon quads are the fastest.....but surely a single fin is...less drag even though it is usually longer.

[Beasho]

Last year I was testing all sorts of fins and configurations.  I spoke with STRETCH in Santa Cruz.  He, William Riedel, tends to be more scientifically minded than the average surf board shaper. 

According to STRETCH the speed of a board from fastest to slowest would be in the following order:

1.   Twin Fin
2.   Quad
3.   Thruster
4.   Single Fin

[dietlin]

I think there's too many variables with fins (template, size, placement (distance from tail, toe-in, cant), material, foil) to generalize like that.

Is this fast or slow:?
 

[dietlin]

...and those fin variables all interact differently with the board variables; rocker, rail shape, bottom contours, tail shape...

[Pierre]

Sorry to say about racing boards, tri or twin fin setup is a great idea, ventral fin design  is totally idiot.
you need fins at the tail when down winding, you need fin fore when upwinding or sidewind course. replace ventral fin with a removable or pivoting centerboard like on sailing dinghies or some win surfboards, OK; Ventral fin solution is a non- solution. Generally fin shape,size, position and stiffness is also a great issue depending on style and technique, not forgetting conditions...

For surf, fin layout depend on the way you surf and you feel... the smallest is the best if I want a reactive and handy board, the large single fin if I like a old school nose riding style, a tri-fin if I like an agressive style, a quad if I like a speed shape... but fin setup must match with board shape.... difficult to explain...

[Pierre]

Sorry to say about racing boards, tri or twin fin setup is a great idea, ventral fin design  is totally idiot.
you need fins at the tail when down winding, you need fin fore when upwinding or sidewind course. replace ventral fin with a removable or pivoting centerboard like on sailing dinghies or some win surfboards, OK; Ventral fin solution is a non- solution. Generally fin shape,size, position and stiffness is also a great issue depending on style and technique, not forgetting conditions...

For surf, fin layout depend on the way you surf and you feel... the smallest is the best if I want a reactive and handy board, the large single fin if I like a old school nose riding style, a tri-fin if I like an agressive style, a quad if I like a speed shape... but fin setup must match with board shape.... difficult to explain...

[Larry Allison]

Sorry to say about racing boards, tri or twin fin setup is a great idea, ventral fin design  is totally idiot.
you need fins at the tail when down winding, you need fin fore when upwinding or sidewind course. replace ventral fin with a removable or pivoting centerboard like on sailing dinghies or some win surfboards, OK; Ventral fin solution is a non- solution. Generally fin shape,size, position and stiffness is also a great issue depending on style and technique, not forgetting conditions...

For surf, fin layout depend on the way you surf and you feel... the smallest is the best if I want a reactive and handy board, the large single fin if I like a old school nose riding style, a tri-fin if I like an agressive style, a quad if I like a speed shape... but fin setup must match with board shape.... difficult to explain...

You have NO understanding of Ventral concept or fins period with alot of other posts I have seen of yours. But when someone that is clueless like you calls me a idiot I have to say something.