I've just started researching the theory of quad-fin design. I came across this interview with Keith Teboul. http://pozonews-en.blogspot.com/2010/03 ... rview.html

I've heard some discussion in various posts, but I thought I'd start a discussion topic here so we could post information and opinions in one spot.

The Boards forum has some good threads on Quads/triis/twins, etc. Looks like there are a few iterations of the quad style set up; some with larger front fins vs larger rear fins, and others with similar sized fins.

I'd love to try a quad. Sounds like the added up wind ability and positive tracking feel for jumping should make it good for all around sailing as well as waves. My biggest complaints with my twin are the higher power required to get it planing as well as the lower upwind ability (unless lit). I've yet to sail anything more maneuverable however, and I'm still getting to know how my twin likes to be sailed. It's exciting to see so many ideas being channelled back into board design.

The Quatro and Starboard quads have different set-ups for the fins (big rear vs big front fins) and they sound like you need to adapt to a rail driven bottom turn a bit more as opposed to pivoting off of the back foot for wave sailing. In fact, a lot of guys are running their quads without the smaller front fins to get the easy sailing feel of a twin. For our sloppy side-on CB conditions, I love the extreme looseness of the twin. You can redirect instantly and keep the board moving and the sail powered up faster after turning it on the wave relative to a stiffer feeling single fin or grippier quad (as I understand from my reading). I wonder how the quads will work for this style of sailing?

Ultimately the core aspect of performance comes from the hull shape, not just the number of fins. I'd love to see a single fin design eventually evolve to combine all of the best aspects of early planing, upwind ability, jumping, and turning ability of a multi fin board. The simplicity of one fin is easier on the wallet as well!

The next few seasons will see a distilling and fine tuning of the various multi-fin designs, and the single fin shapes should reap the benefits of these new discoveries and modified hull "foam flows".

Thanks WD...somehow I knew you'd be the first to respond...

BOARDS discussion on Keith's interview
http://boards.mpora.com/forums/keith-te ... 54031.html

Another recent thread: Quad boards – punter review, fin drive etc
http://boards.mpora.com/forums/quad-boa ... 53745.html

http://ncpaddlesurfer.blogspot.com/sear ... results=20
See article on "Why Quads rule" more surf and SUP but it's much the same for a windsurf board on a wave. Have only sailed the evil twin a couple of times in decent wind but no down the line. I am still trying to figure it out. Super loose. It requires good steady wind and me working on my technique to get it up wind. I think it will require more forward weight and driving into the turn for me to get the best of it. Reports on Starboard quad is that it gives more drive in the bottom turn. ( Not that we get many of them at cb) and it is very good going up wind. Plus faster but that maybe due to fin set up.

I liked the Witchcraft board maker's post talking about his innovation: gluing the flat sides of the assymetricals together so no water could flow over them, reducing drag, and allowing them to be mounted in a single slot!

I wouldn't consider a quad until Winddoc get's one

http://www.boardseekermag.com/windsurfi ... 0-119.html
dated? apparently the top turn, not bottom turn is the key advantage and they confirm better upwind ability

http://www.associatedcontent.com/articl ... tml?cat=14 Why stop @ 4 !!! http://www.bbc.co.uk/wales/surfing/imag ... b_tail.jpg

as tempting as it is to get out there on the cutting edge of windsurf board 'progress' i can't say conclusively that my single fin is holding me back. Since I sail DTL approximately 0.027% of my TOW i don't think i would truly reap the benefit a quad might offer.
it would be fun to take a spin on one i bet. I do like the 4 fin setup on my surfboard. I think 5 makes more sense, at least you can run it as a single. btw i believe this is an option on the starboard quads.

DD,

You're closer to riding a quad than most of us. Isn't your "single" really a trifin?

After spending two weeks SUP'n last may, I definitely preferred the thruster setup on the board over running it with a single fin. Far "turnier" waaayy more fun. I can only imagine the same would be true for my windsurf board, but at the cost of some speed and early planing. That seems to be the same conclusion the mags have drawn on the RRD Wave Thruster. On the flip side, 1 fin is simple, less to break and less money, pretty hard to argue against that!

i have had the RRD tri fin since '06, i keep putting the side fins on then taking them off. they feel really fun for riding and cranking upwind but the trade off in speed is a downer, especially when you are looking to boost a massive combo. last spring i had the 3 fins going at CB, i was on a full plane and bean flew by me on his fsw like i was dragging a kelp bed. My side fins are just little kite fins too.

Now that the sun is shining and the water is warm, are you going to come out of hibernation Dave?

I am trying to stick to my Lasik recovery schedule.. i should have the all clear in a couple weeks.. potentially i could sail and just not fall in.

nanmoo wrote: On the flip side, 1 fin is simple, less to break and less money, pretty hard to argue against that!

If you break off your single fin you are hosed.. if you have 4 fins and you break one, presumably you still have three good ones left!

Just keep your eyes shut! Half the time when I am sailing I have salt water in my eyes and can't see anyways.