Performance twin fin placement question

[ChaseTMP]

http://imgur.com/a/l8bHnfG

Assuming the Futures' slot is 4.5", I printed this image out and did some quick measurements/math and by my calculations (using a 2.5" physical measurement of the Futures box that = 4.5"), I'm coming up with 7.2" from the tip of the tail. I'm assuming the rear part of the fin slot would be where the rear shaper's dot would be?

 

[jkb]

http://imgur.com/a/l8bHnfG

Assuming the Futures' slot is 4.5", I printed this image out and did some quick measurements/math and by my calculations (using a 2.5" physical measurement of the Futures box that = 4.5"), I'm coming up with 7.2" from the tip of the tail. I'm assuming the rear part of the fin slot would be where the rear shaper's dot would be?

Depends on the fins you use (or more accurately the fins that the shaper intends to use).

As Greg mentioned earlier, Tedshreds fins aren't actually set at 8, they are at 6 1/2 because the trailing edge of the fin is 6 1/2" up from the tip of the tail. The trailing edge of some twin templates extend well beyond the back of the Futures box.

 

[tedshred5]

Depends on the fins you use (or the fins that the shaper intends to use).

As Greg mentioned earlier, Tedshreds fins aren't actually set at 8, they are at 6 1/2 because the trailing edge of the fin is 6 1/2" up from the tip of the tail. The trailing edge of some twin templates extend well beyond the back of the Futures box.

that makes sense. I just assumed (incorrectly) I should be measuring from the end of the fin box. I've got the Merrick keels in the board which hang over the edge quite a bit, and my board's a TKF. The videos I've seen of the Bullet Twin being surfed, I think it's been with the Aipa twins which stay pretty close to the edge of the finbox.

 

[griffinsurfboard]

Edumacation going on right here ! ;-)

sh!t - I'm Old

 

[VonMeister]

If one were to design a fin around the futures box intentionally what is the issue?

If you are forced to make a design change due to the limitation of the box it's going to be near impossible to make something just as good if the conditions were otherwise. There's a lot of talented fin makers out there for decades. No one has settled on a design lifting the base of the fin off the board until they were forced into it by Futures box design.

 

[griffinsurfboard]

The base is the initial part of lift and hold
Area reduces from that as it moves into the higher pressure area of back and up

 

[ChaseTMP]

I'm going to be using one of three FCSII templates: Power-twin, AM or MR. I potentially want to tell the shaper to move the fins back from his regular/preferred 8.5" twin placement. Since we're using the Bullet Twin as an inspiration and it's Futures boxes look closer than what the shaper is accustomed to placing twins at, I want to ask him to move them back (maybe 1 1/4"?). I'm trying to do the legwork and give a placement number based on what I'm seeing on the Bullet Twin, (and the wealth of knowledge around here) without making him feel like he's totally copying a design exactly (which he's not). I also want to get something that I have the best chance of being stoked on without having to use a trailing fin, which the shaper was promoting and everything I've read/heard about the Bullet Twin was encouraging for what I wanted out of the board (any easy transition between it and my HPSB's/thrusters). I tried pretty hard just to get a custom Stacey, but there was too much negative energy with how they're operating in the US and I got pretty soured pursuing a board through them.

 

[VonMeister]

Bio-mimicry would suggest the fish and birds figured it out first before the board makers were forced to follow?

I never bought the argument that fish or birds have anything to do with successful fin design. Fish don't look like fins, not in the least. Birds would have to travel at several hundred miles per hour for air to have the density of water. Neither operate in any way like a surfboard, move through resistance like a surfboard, or under changing leverages like a surfboard.

 

[griffinsurfboard]

Bio-mimicry would suggest the fish and birds figured it out first before the board makers were forced to follow?

curious if there were glass ons with this type of separation at the base before fin boxes got us picking sides

No reason to try and help you

Controlled lift is that " Magic " feeling that all pursue and some have found .

 

[griffinsurfboard]

Tim deserves a shaper of the year
So do many others
This should never have ended

 

[need 4 speed]

ChaseTMP:
I like the power twin or the EN for a modern twin
build around that base length
Also check out @blackfinsurf on IG
nice twin template and he can probably do custom fin position if you needed

 

[ChaseTMP]

Am I correct in thinking that a twin fin "washing out" in a turn would be lessened by moving the fins back? I would think it'd stiffen things up. When I proposed to the shaper the idea of moving the fins back an 1.25", he said that was pretty far back and that the repercussions were that the board would have a higher propensity to "wash out" in a turn. He (Dan Cobley) has been shaping for over 20 years and is really good surfer, so I know he can communicate shapes/feel accurately. He primarily longboards and only rides shortboards when the waves are bigger, so he's probably not taking twins out that often and his customer base gets more fishy style twins.

 

[griffinsurfboard]

I've been making my current twin since 1986 , fins have moved 3/16" in all those years .

They were developed thru my surfing and what worked best , not what sells .

Others did so too but are gone .

 

[need 4 speed]

When I got back to about 6 1/2, it felt like I wasn’t getting the projection out of turns . So I went back to 7- 7 1/2” and I seem to like it there. But I surf twinzer so I also have a canard, make my own fins, and scrub my own boards. I’m sure the experts on the forum can help you

 

[Havoc]

my neighbor just ordered a wtf as a twin keel with futures boxes. anyone ridden a wtf twinzer?

 

[need 4 speed]

"Am I correct in thinking that a twin fin "washing out" in a turn would be lessened by moving the fins back? I would it'd stiffen things up."
for the most part I would say yes. I wouldn't like the fins placed past 8.5"
there is more than just placement to consider toe,cant, and position from rail are all part of the equation
trial and error. that's one reason why Ev uses 4 way
imo

 

[need 4 speed]

my neighbor just ordered a wtf as a twin keel with futures boxes. anyone ridden a wtf twinzer?

I had a a straight twinzer fish(same outline) way more maneuverable than a keel.
he should try it with some twinzer fins(T1?) depends on box placement

 

[paunch23]

I had never seen an MR in real life. Looks so fun

 

[000]

iirc MR places his fins at 10"

 

[teeroi]

I was debating whether to post this. But here’s the twin in action at my regular summer spot that has been surfable for the last couple of weeks. Swipe left for rewind clip.

http://instagr.am/p/B76K1jQDpwA/