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DanWeiss



Joined: 24 Jun 2008
Posts: 1889
Location: Connecticut, USA

PostPosted: Mon Oct 28, 2013 12:13 pm    Post subject: Reply with quote

The subject of board weight caught my attention. Without specific comment on the CarbOne, its generally true that a lighter board helps large and small riders roughly equally. I liken this to switching from steel wheels to forged aluminum on a car. Anything that reduces the unsprung weight of a car, that being the weight not borne by the suspension, like wheels and tires, adds considerable control and stability to the car's performance. It's usually the first and least expensive change on a car that gives the largest performance gain.

Similarly, moving and controlling an object at the end of our limbs becomes easier in most circumstances when that object has a lower mass. That's pretty obvious. What may not be so obvious is the amount of energy the board transmits to us and how a light board often allows us to depend less on the largest muscle groups when manipulating the board. I'm sure most of us know that a 12 lb slalom board is far easier to sail than an 18 lb board of the same shape. What is now way back when, Seatrend produced racing boards in three different weights and constructions. Even though the construction differences did account for a lot of the difference, the lightest models were far easier to control and planed up far better than the basic construction. They also proved less exhausting to sail, which meant a great deal to people wanting extend their sessions. So many non-racers purchased the middle and light-weight models.

Assuming equal stiffness, a really light board can be a bit more "flighty" when the rig is very powered and steep chop appears. The stiffness numbers, however, vary in boards of the same shape but with different construction. While I am convinced that a board can be too stiff, that usually is a problem only with short boards designed for big chop and high wind. For a shape of the Kona One and CarbOne, there is no question the higher performance comes from the CarbOne. It planes up earlier, penetrates lulls better and puts less disrupted motion into the rig. It may take a more aggressive style to keep in controlled in short chop, but the technique isn't difficult.

The weight difference between the Kona One and CarbOne is significant at nearly 8 lb and, when planing, a good deal of the difference tends to hang over the water on the Kona One.

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jingebritsen



Joined: 21 Aug 2002
Posts: 2293

PostPosted: Tue Oct 29, 2013 4:11 am    Post subject: Reply with quote

to add to, and somewhat argue with DW, is the fact that higher end boards also allow a rider to notice the strength and weaknesses of fins. quite a few of the boards tested by WS Mag had very low wind oriented fins. helped with the target use of these boards at the expense of higher wind app's. the perception of flightiness when lit up was greatly exaggerated in some cases, by some sailors.
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GURGLETROUSERS



Joined: 30 Dec 2009
Posts: 1251

PostPosted: Tue Oct 29, 2013 4:40 am    Post subject: Reply with quote

Quite so. Further, to be 'lit up' on a lighter longboard, with too big a fin, is more of a handful than similar on a heavier longboard. (Assuming you are trying to keep on a straight course.)

The forces of inertia are a help in taming a tendency to flightiness, and you can more easily control a bigger fin if needs be. Indeed, if carrying 'luggage' on deck, as in cruising, you are entering battleship territory. No pesky wind will get its own way then! Laughing
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Sailboarder



Joined: 10 Apr 2011
Posts: 331

PostPosted: Tue Oct 29, 2013 7:24 am    Post subject: Reply with quote

DanWeiss wrote:
It planes up earlier, penetrates lulls better and puts less disrupted motion into the rig. It may take a more aggressive style to keep in controlled in short chop, but the technique isn't difficult.


I still wonder why it will plane earlier and longer in the lulls. Is it because one can have better control over it? Or because the board will conform better to the water state, akin to lighter wheels on a car?
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whitevan01



Joined: 29 Jun 2007
Posts: 423

PostPosted: Tue Oct 29, 2013 9:08 am    Post subject: Reply with quote

Isaac Newton and some other smart guys figured this all out back in the way old day.

1. acceleration = force/mass, so less mass, greater acceleration (ease of planing) for a given force (sail size/wind strength). However, that also means quicker de-celeration in a lull, which it seems can be offset somewhat by #2.

2. A lighter board of a given volume will have more "float", that is reserve volume, than a heavier board. So adding again to ease of planing (Archimedes waaaay back when and Daniel Bernoulli of the famous and extremely scientifically prolific Bernoulli family).
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Sailboarder



Joined: 10 Apr 2011
Posts: 331

PostPosted: Tue Oct 29, 2013 8:12 pm    Post subject: Reply with quote

As an engineer, I figured this too, thanks to learning from these great people findings.

However, for typical boards, the gain is about 1% of vessel weight (rider + rest), and people still rave about the lighter boards.

I think Dan analogy is important for windsurfing, I just wonder what happens exactly. I guess pumping the fin can be easier, and maybe pushing the board over the bow wave with your feet. Or maybe the board will follow better the crest and throughs of chop, reducing the drag in the end.
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bmoore98



Joined: 05 Apr 2004
Posts: 20

PostPosted: Tue Oct 29, 2013 10:07 pm    Post subject: Reply with quote

I still have not taken the CarbOne out for a second time yet. As long as we're talking about weight here are some comparisons I made over the weekend. These weights are for the boards and foot straps.

BIC Techno Formula 25.20 lbs
Equipe carbon 30.50 lbs
Kona CarbOne 31.05 lbs
Mistral Competition Club 39.35 lbs

I no longer have a Kona One to weigh but the last time I weighed one it was 38 or 39 lbs.

Here's the dagger board weights.

Equipe carbon dagger 1.95 lbs
CarbOne carbon dagger 2.70 lbs
Comp club dagger 3.05 lbs

I hope to compare these boards back to back soon. I now wish I had kept the K1 long enough to compare with the CarbOne but I kind of needed to raise some money for the new board.
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GURGLETROUSERS



Joined: 30 Dec 2009
Posts: 1251

PostPosted: Wed Oct 30, 2013 5:22 am    Post subject: Reply with quote

An interesting comment Sailboarder, about longboards following the crests and troughs in chop.

The thing I like about the average heavier longboard taking short steepish wind blown chop at planing speed, is the 'ironing' effect of length. The front end appears more to 'carve into' and dampen the lift, rather than 'lever' the whole length of board about. I've always assumed the weight is a help in that respect. (I liken the action to that of a destroyer at speed in a swell - a sort of 'get out of my way swell, I'm coming through you!')

Given that weight shouldn't affect top speed, just acceleration, what would make the lighter carbon Kona (if same size and shape) faster in those kind of conditions, and would it be a rougher more bouncy ride if board weight really does make such a difference?

There does seem to be some confusion here.
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jingebritsen



Joined: 21 Aug 2002
Posts: 2293

PostPosted: Wed Oct 30, 2013 6:01 am    Post subject: Reply with quote

steve gottlieb and i tested and re tested the techno 283 vs the hyfly 283 carbon ride some years ago. same sails, fins, masts, etc. conclusions:

carbon board had better early planing, and better lit up performances.

both did equally well in the middle wind range.

carbon board cornered better. had better hole shots.

stability is a misnomer to lots of folks, even seasoned seafarers.
http://sailskills.co.uk/Stability/sailskills_stability_stability_explained.html

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GURGLETROUSERS



Joined: 30 Dec 2009
Posts: 1251

PostPosted: Wed Oct 30, 2013 11:49 am    Post subject: Reply with quote

As a kayaker (dabbled in design and building) I'm aware of stabilty (primary and secondary) in displacement craft, but planing performance has its own set of rules.

Boards magazine also tested identical short boards in heavier and lighter construction. (G.P.S. recorded performance) and their main conclusion (trying to keep advertisers on side, I expect) was that the lighter FELT nicer. They found there was little other difference.

Since a Kona has now been recorded at very high speed (over 35 m.p.h. wasn't it) are we to assume that the lighter, stiffer carbon version will be even faster? And if so, why?
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