Piercing Bows...What works and where?

[TallDude]

I actually think that the pitching they describe in the M&M video is a fore-aft motion. They are trying to level out that motion (almost like a foil) with the piercing bow. The side to side motion is a roll, which I think effects the stability more. I designed my unlimited board with very soft chines, and it does roll quite a bit. Sometimes I wish they were a little harder, but when I see pictures of how quite my board is through the water, I know it's efficient. It has almost no wake. From my readings, generally the piercing bow increases the roll effect, which is why it's predominantly use on multi-hull designs. I'm just trying to understand it all myself. Great dialog...

[Strand Leper]

As to near neutral surf sups being a bad idea... It depends on what u r trying to achieve. I am trying to find the point where volume tradeoff versus short board feel intersect. I don't want to plane onto a wave super early... I wanna bury the rail, link turns and hit the lip...'the near neutral SUP wAs rather good at the aforementioned... But the instability tradeoff was too significant.  I should have shed the wettie to give me a little more of a margin but it was too cold.

I will take pics of my piercing bow from all angles...'as soon as the glasser gets his shite together.

[createinquiry]

Didn't even consider that Lep... Was this a board you made just to experiment with or Was it a lender? Can't wait to see the pics on your new arrival!

All this talk sure makes me miss the ocean, I've gotten into the shaping as a fix, and I think it's only making things worse. Especially since most of my ocean time was around SC and I learned to swim and exist in the ocean at T-street.

TallDude...
Completely agree and much better explanation than mine. With regards to stability on this board, did you have fixed footwells, or just a sandard deck?

I'm thinking that if you can lower the footwells, you can make up for some of the  roll stability lost through the piercing hull and a semicircular hull?

[Strand Leper]

It was my shaper Corran Addison's personal board... He is about ten pounds lighter than I, and he made it + 1.5 gallons of float above neutral for him.  He is going to make one that is + 1.5 gallons for me... 90ish liters I think.

Dying for my new racer.  Never say anything bad about ur glasser....

First he is finishing my racer, then he is finishing my 8'3" by 27 by 3.4...

He calls his tiny ones "the Push" series... (as in pushing yourself and pushing the limit...) Mine is going to be 8 by 26 by 3.2

Funny, I told my wife I was thinning the quiver... Sell three, get three more is not exactly quiver thinning...

[SoCalSupper]

Tim-im sure youve seen this but if not and for others this is a great site for thinning or increasing your quiver.

http://www.eatonsurf.com/UsedPaddleboardsRedux.htm

Caution-side effects of using this site include pissed off wife because you said no more boards and now you want to just call about this one more board!

Tip: have Proflowers site ready on the back button.

[lazymodo]

Personally, Im not stuck on making a surfboard with a fancy nose, actually im doing all my research from the areas of olympic canoe/kayak, oc1"s, and surf ski's.
If your talking about reducing wetted surface area wouldnt you want as much of the board as possible out of the water?
The roll thing i wonder about as well. I think the reference is for and aft . How could it affect side to side stability? I put 1" of roll in the bottom of my board wondering if id even be able to paddle it and its actually quite stable. A little tippy , but as it comes over on to the square rail it stabilizes (secondary). The roll has a huge effect on the smooth ride in my experience, just goes through the water easier.  
Maybe,,,,, its just the latest fad. Seems to be a multihull thing. Don't see may paddle powered monohulls( OC1, ski's )with the piercing bows, a lot of plumb bows though. A case of been there done that??? We shall see.
A link to a slight shot of the bottom of an m&m, looks pretty rounded.
http://www.facebook.com/photo.php?fbid=160960330618317&set=t.1304168835&type=1&theater

[TallDude]

Here is a great article, that answers a lot of questions about pitching, bows, rocker, and waterline. ( http://www.epickayaks.com/news/news/want-rocker-think-again ) It really hits home about the extended-piercing bow on my board. My board does have a little nose rocker, and it does slap down hard after it pierces a larger ocean swell. I'm going to think about this for a while.

[lazymodo]

Heres a great little article on this very subject. Follow the leads to the companies website. Wow . that thing looks cool,have GOT to paddle one of these things.
http://www.surfski.info/latest-news/item/1281-point-65-bourbon-orca-design-notes.html

[Strand Leper]

So Cal,

I've trolled that site a time or two... maybe been in the shop once or twice...

One thing that really stuck with me on the piercing bow idea is the reduced yaw that I think a piercing bow should (by nature) demonstrate.

Anyone? 

(Mine was ready on Saturday Morning... AFTER I picked up the wife to take her to the "high tea" at the St. Regis... don't laugh... those Kobe Beef sliders protein style were tasty!)  Gonna swing by and pick her (the board) up this week... IF Corran hasn't broken her by then.  He is so excited about the board that he asked me if he could paddle her first... pretty please... I am working on the percentage discount per rail ding right now...

Tim

[createinquiry]

Would completely agree that reduced yaw should occur. In my mind this would be true of any narrow, "shorter" race length board given the fact that buoyant force is based on the water displaced. So all these short narrow boards will have relatively large portions of the boards below waterline, helping to reduce yaw.

So it would seem that the piercing hull have advantages in reducing pitch, similar if not better in reducing yaw,  but the concern seems to be with roll.

I can only get my mind around two ways that the roll can be reduced:
1) lower the CG using footwells or 2) flatten at least some portion of the bottom, realizing that this increases drag due to the increased WSA.

Are there other means of reducing roll that I am missing?

[TallDude]

One thing that your missing CI, is the fin or keel effect. This is something I have some real first hand experience with. I was testing a 16' race board for Infinity that had a front steering fin. I helped build the tiller, and I tested the board in all kinds of conditions. With the front fin on (4' back from the nose), it tracked amazingly. I could paddle cross-wind and switch hands with out drifting off course. Just like using your dagger board on a windsurfer. But something I didn't expect, was how much more stable the board became. It felt like the board got 4" wider, at least. With the fin out, it just felt like any other race board as far as stability. I didn't notice any extra drag either with the front fin in. The newer Richmond boards have two, inline rear fins (like Thomas Maximus's board). I took the board into some heavy open ocean conditions (small craft advisory type) and smashing down the faces of the capping waves broke the tiller and fin pivit mechanism. I would hit the next wave on an angle, and it just slammed the fin to the side. It was not fun getting back to safe harbor. I've often thought about mounting a forward fixed fin on my board. I know it wouldn't help when you have surf finishes. Actually, Larry Allison recommended I put a small forward fin on my unlimited board. I thought, is he just trying to sell me another fin?

[robon]

One thing that your missing CI, is the fin or keel effect. This is something I have some real first hand experience with. I was testing a 16' race board for Infinity that had a front steering fin. I helped build the tiller, and I tested the board in all kinds of conditions. With the front fin on (4' back from the nose), it tracked amazingly. I could paddle cross-wind and switch hands with out drifting off course. Just like using your dagger board on a windsurfer. But something I didn't expect, was how much more stable the board became. It felt like the board got 4" wider, at least. With the fin out, it just felt like any other race board as far as stability. I didn't notice any extra drag either with the front fin in. The newer Richmond boards have two, inline rear fins (like Thomas Maximus's board). I took the board into some heavy open ocean conditions (small craft advisory type) and smashing down the faces of the capping waves broke the tiller and fin pivit mechanism. I would hit the next wave on an angle, and it just slammed the fin to the side. It was not fun getting back to safe harbor. I've often thought about mounting a forward fixed fin on my board. I know it wouldn't help when you have surf finishes. Actually, Larry Allison recommended I put a small forward fin on my unlimited board. I thought, is he just trying to sell me another fin?

I noticed Imagine/Corran put a forward fin on their 14' and 16' plastic SUPs. These models aren't exactly wide at 28.5", so I wonder if these boards will feel a little more stable with the front fin?

[raf]

Tim, I think its great that you aren't bothered knowing Corran will always be Candi's 1st.  I'm sure he won't hold it over you either 

[Strand Leper]

Actually Corran confessed that he will not ride her until I do... and that he was just pulling my chain... he does that sometimes...

I would have been bummed, because according to half of the androgynous population of Montreal, I would NEVER have measured up!

Tim

[TallDude]

Robon,
You're right. 'Eco Imagine' actually has them on their racing foam/ glass boards as well. I won't name names, but someone (who totally knows how to surf big boards) was trying to surf a SUP race board with the front fin, and hit someone. Of course, he totally apologized and made things right, but if he couldn't pull it off, I doubt I could for sure. Maybe just straight? How about a small retractable (dagger board) fin?