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Old 29th April 2010, 01:57 PM   #11
ChrisN
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Davide, yes I saw that article from Boards; SURF focused on the larger sizes, as I think that's where lighter construction should have an assumed impact. If you see the graphs in detail, SURF reported considerable effects of JP, Taboo and Fanatic heavy-to-lightweight constructions. So, from that perpective, both tests agree that in the larger sizes/volumes there is an effect in planning, sailing through lulls, top speed, and upwind ability.

However, as many people highlighted, beyond skill (which is elementary!), the most important factors affecting early planning are Width, Fin Length and Stiffness/Rigidity of the board. I think the formula I presented given Agrelon's excellent thinking on the the minimal effect of weight deltas btw. WC and W, compiles most of our experienced-based discussions.

Thus, the question in the end is not Weight per say, but rather Rigidity which then should explain what promotes earler planning the most in lightweight constructions. I think Anders Bringdal could speak of that, as he contributed to the Hydroptere (which sailed above 61 knots and broke the world speed record).
Moreover, Oracle's America Cup winning boat showed in Valencia a new concept of light wind sailing and reached phenomenal speeds for such a low winds speed! While Hydroptere's construction showed how low Surface Traction affect speed potential and planning ability, Oracle's Wing-rather-than-Sail showed that Sail Shape Rigidity (SSR) also has a grand effect on very low winds - this is one of my missing Parameters in the formula above. On the SSR check out the designers explanations (NP, Gaastra, Severne, etc. will certainly been reading with interest)...

But we are still only speculating - as Belscorpio highlights we are all anxiously awaiting the SB "engineering" gurus with their public approach to innovation, to enlighten us.


PS: If not we could pose the same question to Werner (JP), Pieter/Werner (Fanatic), FinnM (RRD), Fabien (from Taboo), and Anders (AB, now running Mistral). All market "lightweight" = more expensive constructions...
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Old 29th April 2010, 10:21 PM   #12
ChrisN
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Originally Posted by BelSkorpio View Post
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ChrisN,
I've heard several years ago the following statement:

"For every 1 kg a board weighs less, a rider can weigh 10 kg more to obtain the same plan(n)ing capabilities."


I must admit that I cannot 100% explain it scientifically, nor do I know if this statement is right in the first place. If I still remember it well, it got something to do with the fact that you can't just add the full weight of the rider with the weight of the board to obtain a total weight of "mass" on wich you could apply the 2nd law of Newton (F=m*a) to calculate the acceleration an object gets when submitted to a constant force.
I think they explained it in a way that your body weight partly get's lifted up by the sail, reducing the actual body weight that can be added to the weight of the board. This is probably a little bit less true when you 're not in planing condition yet, because then your body weight is not really "suspended" to the sail yet that much.

I don't know if I make sense, but I thought I'd mention this as well, since we are dealing with this topic more and more theoretically

Any reactions are welcome.
BelSkorpio, this is really interesting! If your "rule-of-thump" is correct then an 80 Kg guy on an iS144 Wood (~ 7,79 kg) will plan as early as an 86 kg dude on an iS144 WoodCarbon (~7,14 kg). I think that you are absolutely right that part of our weight are expended to counteract the sail lateral forces while on planning (thus we "relax" in the trapez). Prior to planning it's a "fight" - imagine large sail in a gust!

Agrelon, I quoted Belscorpio's points above, given that you used Newton formula to estimate the effect of the board weight delta. If this is even partly true, then that delta have a LOT more effect on force than you estimated!

As mentioned though, Weight of Sailor and Equipment was only part of the LWP equation above, where Board Rigidity and Surface Drag together with our discussion on Sail Shape Rigidity (the Oracle Americas Cup example), have significant effect as you move from Wood to Carbon constructions. The Formula from above can then be rewritten to the following parameters in priority of importance/ effect:

LWP = SAILOR_SKILL*c1 + BOARD_WIDTH*c2 + FIN_LENGTH*c3 + BOARD_RIGIDITY*c4 + (1/BOARD_SURFACE_DRAG)*c5 + SAIL_RIGIDITY*c6 + SAIL_SIZE*c7 + (1/WEIGHT_SAILOR)*c8 + (1/WEIGHT_EQUIPM)*c9 + BOARD_VOLUME*c10

Each of the parameters are positively affecting LowWindPlanning (LWP) potential except Surface drag and Weight that have an inverse effect (i.e. more drag less LWP meaning more wind is needed). Recall that HIGH LWP potential translates into LESS wind in knots for planning.

For example, a light/70 kg advanced sailor riding a 100 cm, 168L Formula Lightweight/Carbon construction Board with a Stable 12m2 REFLEX sail on 70 cm fins in sailed by a will plan earlier. There is naturally an upper threshold for LWP or a lower limit in knots for any construction with a given surface drag, which for a Formula board must be around 6 knots (unless you use hydrofoils)

The last America's Cup race in Valencia was done on max. 6 knots of wind with Oracle-BMW covering the track at blistering speed. This massive boat with their 630m2 wing main-sail, is a super-rigid, super-wide trimaran that can carry monstrous sail areas (>2K m2) on its 55m mast and sail on a minimum drag 20m waterline of one its hulls, should be sufficient proof of the Width, Drag and Rigidity arguments. This winning concept was able to plan 1-2 knots earlier than the other boat which translated into 600 m on the finish line! Check out a picture showing Winner with the Wing on a training day sailing on max 5 knots of wind on one hull!



Hope that the parameters should be pretty obvious by now, yet you are welcome to comment, while we ALL still wait for Godot!
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Old 30th April 2010, 03:23 AM   #13
davide
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However, as many people highlighted, beyond skill (which is elementary!), the most important factors affecting early planning are Width, Fin Length and Stiffness/Rigidity of the board. I think the formula I presented given Agrelon's excellent thinking on the the minimal effect of weight deltas btw. WC and W, compiles most of our experienced-based discussions.
I completely agree, weight, within the limits we are discussing, is fairly irrelevant. What makes a difference between otherwise identical boards might be the Stiffness/Rigidity but even there it is unclear which type is "superior". We all know that a stiff board is fine in light air, but becomes very hard to manage (and possibly slower) in hard weather, and I am pretty sure that the weight of the sailor is a component: at 70Kg I might not need as stiff a board as a 120 Kg sailor ...

I really believe that most of the carbon-here-and-there is marketing, it is not even clear that a 100% carbon board is the way to go, and probably it is not... it would be much more useful for the general user to have a heavier but stronger construction, such has witchcraft (http://www.witchcraft.nu/) offers. Starboard is actually doing a fairly honest job, offering carbon-wood/lighter construction in moderation and only where the advantage (for a racer) might be more perceptible.

Last edited by davide; 30th April 2010 at 03:26 AM.
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Old 30th April 2010, 06:01 PM   #14
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Regarding the stiffnes and spoken from a practical point of view, I know that there was a lot difference between e.g. the old tiga/hifly "plastic" and the other epoxy sandwich boards of the nineties. The tiga/hifly plastic was great in "heavy weather" wave conditions. They felt like they were reforming so much that they seemed to adjust themselves almost completely to the rough water surface. Very solid, indestructable, great control, BUT much slower in planning. No doubt in my mind. Material that reforms, creates a larger wetted surface, so more drag. All very logic.

So, especially in flat water and low wind conditions, I am also convinced that stiffness is a very important factor. But the question remains, once you have obtained a certain level of stiffness, what will those few percentages of extra stiffnes, gained by using carbon, still matter ? How many knots earlier planning ?
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Old 3rd May 2010, 12:55 PM   #15
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http://www.jp-australia.com/2010/index.php?id=574

Will be interesting to see what test results say about this board. I wonder if it planes even earlier than a formula? Interesting concept though, I guess the closest equivalent in the Naish Freewides, but as Ken pointed out their design may not be so good...

JP claims that it planes as earlier as a formula board, however, with a 56cm fin and 10cm less width this claim remains to be proved.
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Old 3rd May 2010, 04:34 PM   #16
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Yes, interesting indeed, agrelon.

It looks similar to the IS150.

10cm longer and a wider tail, though.

And what's more important, a carbon deck ! LOL
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Old 3rd May 2010, 05:45 PM   #17
ChrisN
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Originally Posted by agrelon View Post
http://www.jp-australia.com/2010/index.php?id=574

Will be interesting to see what test results say about this board. I wonder if it planes even earlier than a formula? Interesting concept though, I guess the closest equivalent in the Naish Freewides, but as Ken pointed out their design may not be so good...

JP claims that it planes as earlier as a formula board, however, with a 56cm fin and 10cm less width this claim remains to be proved.
Agrelon, this is spot on with the comparison we were doing with iS150 which by the way is 93.5 cm wide, so very similar to JP's Super Light Wind (SLW)! The only difference is of course the AGE of the designs, as SB's iSonic 150 is more than 3.5Y old, while JP has a new "blend" design, where as they are writing on the site you mentioned, JP's "..approach was to develop a board which gets planing in minimal winds and allows totally relaxed blasting, and feeling the sensation of speed. We achieved this by simply merging the JP Formula, Slalom and Super Sport shape concept."
This is certainly NOT what SB did as the iS150 was borne from a "pure" slalom heritage of going "faster". I did an simple visual comparison between the 2 shapes - JP SLW and SB iS150 - and one thing is immediately evident beyond that JP is 10 cms longer and 3.5 cm narrower than the iSonic; the JP is wider OFO while iSonic's pintail is making the tail more narrow; the widest point of JB is further forward than on the iS; moreover, the rails are parallel in JP while more oval and narrowing in SB's iS. While not visible, it seems like JP's shape is more thick in the rails overall - see position of footstraps. Actually JP's outline looks a lot like the SB's Formula LWR, yet narrower and more "rounded".



What is interesting is whether JP's SLW would be planning earlier than the iS150 given the details above - that is what the upcoming tests would show. JP is certainly focusing on stiffer/RIGID constructions for the SLW90, as it is only offered in GOLD (KevlarCarbon with Honeycomb) and PRO (Full Carbon); Both are lighweight constructions with the GOLD being the lightest and most rigid in the market!

In summary, while SB will NOT answer our question on the planning differences in various constructions, it seems that the industry is doing it for them. There must be a reason why JP is NOT offering their SLW in FWS (full wood sanwich construction), and why SB's new Formula's are both in WoodCarbon. So type of construction (which for Carbon-based ones equals to higher rigidity and lower weight) is important for early planning in light wind conditions.

While it seems reasonable that JP's SLW90 shape would provide better jibing capabilities and faster Reach speeds plus high-wind stability than comparable Formula Designs, what is interesting is that JP stresses the point that the SLW90 planes as early as a Formula board on a -10cm less width and -14cm shorter fin!
According to our earlier conversation and the "formula" we were developing, width and fin length are some of the most important factors after drag and sailor skill (of course!). Moreover, a WoodCarbon Formula would plan earlier than a Wood Formula right? What SB was not telling us was how much earlier...

So, per definition a SB Formula HSW or JP Formula 100 should plan "earlier" than a JP SLW90 or an SB iSonic 150, presuming the same fin length, sail size, sailor and conditions. For most of us it would be an est.1 knots delta between Formula and JP's new SLW90 and then another knot for iS150. If I sailed the same boards in Wood construction then I could add another knot (in alignment with BelScorpio's rule of thump)!

What I then assume is that for my weight (90kgs), advanced sailor (that can waterstart, jibe, pump large sails), on a 62 cm fin on a 11 m2 freerace sail, SB & JP Formula boards will plan from 8 knots while JP's SLW90 from 9 knots and iS150 from 11 knots (given that it is made in WOOD)...
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Old 3rd May 2010, 07:04 PM   #18
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ChrisN,

Nice on you pointing out the construction restrictions on the new SLW. No doubt they've done this to "ensure" the promised early planing performance and subsequent consumer satisfaction.

I think though that it should be possible to run a fin pretty close to 70cm on the SLW and a sail > 10m2 due to the huge volume and width. At this point, especially in Gold construction, I think that the planing performance of the SLW would definitely be competitive with full on formula gear.

It'll be interesting to get some test results and to see if SB responds in the future with an early planing freeride board (though they may feel that the Serenity has filled that gap). Man I wish I had the budget to go out and try all these new toys!

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Old 3rd May 2010, 09:55 PM   #19
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I guess all of this comes down to how you plan to use the board.

1. Light wind slalom racing - get a giant slalom board.
2. Formula racing - get a formula board.
3. Light wind free riding, earliest planing, highest pointing, deepest running - get a formula board.
4. Light wind free riding, best jibing and reaching comfort - get a giant slalom.
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Old 3rd May 2010, 10:11 PM   #20
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Ken did you see my earliest references on JP's Super Light Wind board above? It is definitely different than the iSonic 150! I think it does combine your 3+4 categories.

If anyone reads the test of the JP SLW 90 154L in PlancheMag May'10, can you please share the results??

And we're still waiting for our innovation SB gurus - funny how they have been avoiding to answer this particular question like a "hot patato", which in my view means they have not tested their own constructions! Else, they would have confidently answered back with a single REMI line - YES or NO...

From what you and everyone else has contributed so far though, we can infer that these constructions do matter A LOT. JP's Light Wind board is certainly only delivered on these.

I'll wait a bit longer, and then I'll ask some other manufacturers too, yet as it seems JP's SLW, which is not "pure" - neither Formula nor Slalom is probably the best answer to combine your 3+4 categories...
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