fin advise

J64TWB · Joined: 24 Dec 2013 Posts: 1685

Want to add an additional fin to my 130L, 72cm free ride board to try and get out on those marginal days where my stock fin won't get me planing. Goal is early planing, upwind performance. Stock fin is a JP 44. Thinking either a race/slalom oriented (maui fin KP race) in either 48 or 50 or Liquid pro in either 48 or 50. Will it help?

I am 145lbs to be paired with a 7.5

U2U2U2 · Posted: Fri Apr 03, 2015 12:29 pm Post subject:

The reason the board doesn't plane is NOT because of the fin, OR fin alone. Its a number of aspects, and could be just that there is not enough wind.

I think a 44cm without looking up a load of research stuff is about the right size, its going to be possible to improve the JP fin. You may go slightly larger and better fin and cure, or NOT

I like the MFC Liquid, and really like a Black Project Fin, BPF, they are super efficient. You need to compare any fin as a replacement with the area as well as the length......

Write Chris at BPF tell him Colorado sent you

coachg · Joined: 10 Sep 2000 Posts: 3550

I pair a 48 cm MFC RC fin with a 7.5 all the time, but I'm 30 lbs heavier than you using an 85 cm wide board. On my 70 cm board I don't go bigger than 44 cm with a 7.5. Too hard on the ankles.

Stock fins generally are not very good. I think a better 44 cm fin is the way to go. MFC Luquid Pro or KP in 44-46 max is a good call. If you want to spend more a Tectonics T-43 is a very powerful fin.

Coachg

swchandler · Joined: 08 Nov 1993 Posts: 10588

These days, fins can highly specialized, particularly when it comes down manufacturing. Being such a light sailor you just might move up to a 46cm course slalom design with more high aspect planform, powerful tip, but soft and flexy overall. If you have the money, I would check out what F4 fins can offer you. Molded fins offer the best out there, particularly for the lighter sailor.

http://www.f4fins.com

If you're grounded in a more affordable world, you really can't go wrong considering Tectonics. I have older 46cm Spitfire and 50cm Mirage course slaloms, and they have served me well over the years. They strike a great balance between powerful and comfortable across a pretty healthy wind range. I wouldn't be thrown off by a more vertical high aspect design. They're a lot more maneuverable than you think.

cgoudie1 · Posted: Fri Apr 03, 2015 2:52 pm Post subject:

I've got a True Ames Sweeper in a 48, it's pretty darned planey, and
not overly stiff in turns. You might like it to get you planing in
about 2 or 3MPH less wind than what currently planes you.

http://www.isthmussailboards.com/True-Ames-Sweeper-Tuttle-Base/productinfo/TASTU/

-Craig

jingebritsen · Joined: 21 Aug 2002 Posts: 3371

easy way to make sure your fin choices do not exceed a board's ability to balance with it well:

measure the bottom of the board one foot off the tail. the width of the board at that point should be the max fin length. anything over that reduces the upside wind range, and tends to offer limited additional lift.

J64TWB · Joined: 24 Dec 2013 Posts: 1685

Interesting jingebritsen. Boards are in Wisconsin, I'm planing on sailing next weekend. I'll check those measurements! Makes sense all. Preferably I would have a wider board for those conditions. Maybe next year. Coachg, what's your 85cm. Board? Could people comment on stiff vs. Flex for lightweight in light winds. I assume fin width is most important for early planing, which true ames sweeper isnt, but maybe has more flex and length? Upright Is better than curve for early planing correct?

coachg · Joined: 10 Sep 2000 Posts: 3550

Area for early planing, not just width or length. Fanatic Falcon 142.

Coachg

J64TWB · Joined: 24 Dec 2013 Posts: 1685

Coachg, at what wind speed and sail range do you use that falcon? What is your next step down when the wind picks up?

cgoudie1 · Posted: Fri Apr 03, 2015 11:28 pm Post subject:

As the Coach says, area is the call, but meat cleaver like fins tend to
top out really really fast, and I find purely vertical fins to spin out abruptly.
Another thing that will help with early planning is a thick fin foil (at least thick at
the leading edge). For light wind I prefer a stiffer fin, but when it honks, and in really rough terrain, a little flex is good. If your goal is to plane as early as possible then the Drake-Curtis 42 or the Drake-Ames 40, or the True Ames Stubbie 38 or 45, but I don't know where you would order the Drake fins (maybe starboard could help), and you'd have to special order the Stubbie 45 from True Ames.

Good Luck,

-Craig