Fins that flex dont actually give any more power. How could they? That springy recoil feeling is just an illusion! The whole time youre leaning on the fin, it’s not driving- it’s releasing power to the rails. After you let off, that’s when it springs back. Boing- boing- boing. Those long flexi fins that came out around 1966-1970 were another sales gimmick to sell the new “revolution” and shorter boards.
Be sure to tell George Greenough and Greg Liddle that their fins are just an illusion…
Sorry, you’re wrong about the sales gimick angle. It’s not a myth. George Greenough is far to ethical and too committed a waterman to ever even consider such a thing. I do agree that they don’t give more drive what they do is allow you to surf more off the rails of the boards and less of the fin. I must agree that the springy feel is an illusion of power but on some bottom configurations a lot of fin drive is self defeating because the board is designed to be more down in the water and create it’s own drive as you turn. Big solid fins on these boards don’t make them go faster they slow them down. Think of how many different kinds of boards there are and then tell me there’s no place for flexible fins. I surf both depending on the conditions and the board I take out and enjoy the performance that both give. There more to the story but I’ll save that for another time. Mahalo, Rich
What if Longer and Smarter is right…what if a rigid, well foiled, expertly templated fin works better, bear in mind GG used stainless steel for his windsurfing fins, wonder how much they flexed.
It depends on the application. For a thruster set up, rigid fins may work better as each outside fin has to work in concert with the stabilizer. On the other hand, TUNED flex single fins with the right bottom/rail/rocker combo turn a dead pivoty turn into fire breathing drivey arcs with tremendous acceleration. Certain hull configurations will not work as they are designed unless the fin has a very specific tuned flex. As you take the pressure off the fin at the end of the turn, the fin will rebound and add a little spurt of additional acceleration. On a particular single fin I ride, that spurt is NOT and illusion. A board with a good flex fin has to be turned a little differently than the same board with a rigid fin to take advantage of the flex. George Greenough uses stainless steel on his paddle fins and they do flex; but it is primarily a twisting flex, not a lateral flex as many think. Bottom line: rigid and flex fins both have their places. But, it is like everything else in surfboard design; they have to work in concert with other design elements to get the most out of them.
Hey Lee Im glad you cleared that up I thought we might have been wrong the last 35 years.
Lee V. for Governor!
For a thruster set up, smaller Greenough “paddle” fins w/torque flex work extremely well… just ask BT. He`s very familiar with the foremost Austrailian application from about 3-4 years ago. Yeah… Lee V. for Governor!
Campaigning would just get in the way of the Swaylock’s Anon. Camp Out. Gotta keep your priorities straight…
Campaigning would just get in the way of the Swaylock’s Anon. Camp Out. Gotta keep your priorities straight…
I’m glad you all brought this up. I’m sure you have seen Gene Coopers Comets. Great looking boards, and I’m sure they ride well. I am thinking of shaping one similar and was wondering if the flex fin was for me. Seems to me they might be forgiving, but I would also be afraid they would give to much in a critical bottom turn. Let me give you an example. A few weeks ago on a head high day at terra mar cove, I (for the heck of it) asked a beginner if I could try his Morey Doyle. It was eight foot. I had one as a ten year old kid, and I thought I would be a bit nastalgic. Well, right away, it was a big disappointment, mostly because of the fins. I could feel those plastic things (tri fin) bending when I was trying to bottom turn in steeper sections. The board literally spun out and slid ass, just like a finless board. It simply couldn’t take the tourque. And it didn’t catch waves as easily as I remembered. So, I quickly gave it back. Maybe if the board had a long single fin it would work better, but the fins had to be four inches. Really weak design (but perfect for shallow whitewater, which is the point, isn’t it). So, will a flex fin perform in a similar way? My goal is to make a 7 foot comet/feather fastback type board that will make wide arching turns at Cardiff Reef on slightly overhead days. Whatchathink?
I’m glad you all brought this up. I’m sure you have seen Gene Coopers Comets. Great looking boards, and I’m sure they ride well. I am thinking of shaping one similar and was wondering if the flex fin was for me. Seems to me they might be forgiving, but I would also be afraid they would give to much in a critical bottom turn. Let me give you an example. A few weeks ago on a head high day at terra mar cove, I (for the heck of it) asked a beginner if I could try his Morey Doyle. It was eight foot. I had one as a ten year old kid, and I thought I would be a bit nastalgic. Well, right away, it was a big disappointment, mostly because of the fins. I could feel those plastic things (tri fin) bending when I was trying to bottom turn in steeper sections. The board literally spun out and slid ass, just like a finless board. It simply couldn’t take the tourque. And it didn’t catch waves as easily as I remembered. So, I quickly gave it back. Maybe if the board had a long single fin it would work better, but the fins had to be four inches. Really weak design (but perfect for shallow whitewater, which is the point, isn’t it). So, will a flex fin perform in a similar way? My goal is to make a 7 foot comet/feather fastback type board that will make wide arching turns at Cardiff Reef on slightly overhead days. Whatchathink?
If you surf at Cardiff Reef, talk to Guy Takayama. (he surfs there alot) He makes flex fins in two shapes. I’ve tried them both, and they work. His philosophy is to keep a wide, stiff base for drive but thin out toward the tip so it flexes. I put a 9" Orca style on my 9’6" pintail on his recommendation, and it completely changed the way the board acted: more speed in trim and more drive in turns. With the right design you won’t lose drive when it flexes.
If you surf at Cardiff Reef, talk to Guy Takayama. (he surfs there alot) He makes flex fins in two shapes. I’ve tried them both, and they work. His philosophy is to keep a wide, stiff base for drive but thin out toward the tip so it flexes. I put a 9" Orca style on my 9’6" pintail on his recommendation, and it completely changed the way the board acted: more speed in trim and more drive in turns. With the right design you won’t lose drive when it flexes.
Actually - the physics of the flexing fin goes… the fin begins to flex at the start of the turn, as pressure is placed on it. Once the pressure and rigidity of the fin equalize (a fraction of a second) the fin flexes no more (assuming that pressure is constant). The turn continues with the fin in the flexed position. Then, as the turn is completed, pressure is relieved from the side of the fin and the fin return to its non-stressed position - straight. Again, this happens in a fraction of a second. Think of it as a coil spring. You press on it, it gives to a point, then when pressure is releaved, it pushes back to acheive its original non-stressed position. So… You loose a tiny amount of drive going into the turn, and gain it on the exit. In between, the flexing of the fin actually smooths out (dampens) the boards response during the turn. Good? Bad? I guess it depends on how you like your board to handle. (like a car with or without a suspension - only no where near as obvious) Either way, it really only makes a very slight difference - hardly discernable to the average rider.
Actually - the physics of the flexing fin goes… the fin begins to flex at the start of the turn, as pressure is placed on it. Once the pressure and rigidity of the fin equalize (a fraction of a second) the fin flexes no more (assuming that pressure is constant). The turn continues with the fin in the flexed position. Then, as the turn is completed, pressure is relieved from the side of the fin and the fin return to its non-stressed position - straight. Again, this happens in a fraction of a second. Think of it as a coil spring. You press on it, it gives to a point, then when pressure is releaved, it pushes back to acheive its original non-stressed position. So… You loose a tiny amount of drive going into the turn, and gain it on the exit. In between, the flexing of the fin actually smooths out (dampens) the boards response during the turn. Good? Bad? I guess it depends on how you like your board to handle. (like a car with or without a suspension - only no where near as obvious) Either way, it really only makes a very slight difference - hardly discernable to the average rider.
Don’t confuse a wiggling fin connection with tuned flex. A good flex fin is designed to bend in a very specific way. Most of them (if not all) have very rigid bases. If you want a good flex fin for the board you are describing, go to the source; liddlesurfboards.com. Order up a 9" or a 9.5" and stick it in a 10" box so you can move it around to tune it in. You’ll never go back to a stiff fin again.
Don’t confuse a wiggling fin connection with tuned flex. A good flex fin is designed to bend in a very specific way. Most of them (if not all) have very rigid bases. If you want a good flex fin for the board you are describing, go to the source; liddlesurfboards.com. Order up a 9" or a 9.5" and stick it in a 10" box so you can move it around to tune it in. You’ll never go back to a stiff fin again.
In general, these work well as does the Liddle fin described by Lee. 
In general, these work well as does the Liddle fin described by Lee.