Base/ edge/core material.

[rynhardt]

The main reason a TT feels incredibly bad to turn is because of the fin to back foot distance. With an SB you foot sits smack on your fines and you can drive that turn pivoting around the back foot and fins. The further away your foot is from the rear fins the worse that drive becomes. so.... My evil plan was to subtly move the fins forward up the board closer to the rear foot. It worked and I have way better drive on the wave face with the fins closer my rear foot. But with a mutant design you can't run too much rear foot bias or backwards riding will be compromised. That is also the reason I ditched the rear thruster. it was too far back and inhibited my turning radius. I also discovered with the quad I didn't need any extra fins. I can hold some incredible pressure on some pretty steep and lumpy faces.

Yeah man, agree with you on this 100%. I moved my fin to right up against the footpad and the board turns on a dime with minimal effort. It was a centre fin though, so did lose some power holding in rough chop,.
My new board will keep the fins near the edge, but moved up from the tips to just behind the footpads, pretty much where your outer thruster fins are.

[rynhardt]

For those interested in a more scientific approach, "The engineering of sport 7, Volume 2", has some research done on snowboards utlising foam vs wood cores.
Just google "experimental measurement of selected snowboard mechanical properties" and view the google ebook.

Anyway, for those too lazy to read the whole article, it comes down to saying that you can achieve the same results with foam as with wood, if you adjust your layup to compensate for the differences in core stiffness.

[downunder]

Sure.
But, I just don't see a foam snowboards
One thing: inserts. How much reinforcement is needed on a foam not to pull it out? Particularly when using boots. Also, a price. One cubic meter of Paulownia from China is $$$, the foam is 5-10 x more...
To be fair, all US boarders are using some sort of locally sourced wood. My PWood is local as well, bamboo 5mm isn't, hence $140 per sheet. The foam 5mm is $160, and I think it is shipped from Sweden. Crazy.

I think it's up to the individual. Myself looking for a nice wood grain boards, with the least possible glassing and carbon footprint. The epoxies, foam, FG and CF are just not Earth friendly, and we utilise wind for power, which is a directly opposite. I find this amusing...

[rynhardt]

Sure.
But, I just don't see a foam snowboards
One thing: inserts. How much reinforcement is needed on a foam not to pull it out? Particularly when using boots. Also, a price. One cubic meter of Paulownia from China is $$$, the foam is 5-10 x more...
To be fair, all US boarders are using some sort of locally sourced wood. My PWood is local as well, bamboo 5mm isn't, hence $140 per sheet. The foam 5mm is $160, and I think it is shipped from Sweden. Crazy.

I think it's up to the individual. Myself looking for a nice wood grain boards, with the least possible glassing and carbon footprint. The epoxies, foam, FG and CF are just not Earth friendly, and we utilise wind for power, which is a directly opposite. I find this amusing...

Yeah I think cost is one of the factors driving the marketing engine to a preference for wood. And you don't need to worry about seperate supports for inserts like with foam. It certainly simplifies the manufacturing process, you need one CnC machine and you're set.

As for environmental impact, it's complex. Total carbon footprint of wood needs to include the logging, transport, processing etc.
None of these industries are particularly green.

And then the board core is a small part of the equipment. Everything else, kites, bars, lines, fins, is synthetic.

[Onthewater860]

Where are people buying your Pawlownia from? Any one building with other woods?
How does bamboo compare to Pawlownia in stiffness, ease of working, glueing?

[plummet]

Talking wood v foam core. Yes you can get the same characteristics of flex. However the foam core will be prone to shear and the board fail sooner that wood core. From my landboard building days it was well known that foamcore only boards failed. They simply couldn't provide the shear strength with the given flex that was required. Now a landboard has a lot harder task to complete than a kiteboard. Kiteboards use the majority of their surface area to displace the impact and flex. So you can get away with a weaker design than that of a landboard.

So.. matching the shear strength and flex of the core to similar to the reinforcement gives you an incredibly strong and robust design, at the expense of weight.

The other major advantage of a wood core is impact resistance. The will core will assist the reinforcement in the instance of an impact. You can take a significant impact with very little damage on a woodcore board. Foamcore ..... not so much.

Summary,

Foamcore lighter weaker design damaged more easily.
Wood core stronger heavier better impact resistance.

[rynhardt]

Foamcore lighter weaker design damaged more easily.
Wood core stronger heavier better impact resistance.

Agree, but you also need to take into account ease of fabrication.
Foam is so easy to work with, especially for a DIYer like me. Not just cutting and sanding, but springback on foam is negligible.
Wood, on the other hand, either requires a pre-shaped core or a fair amount of experimenting with rocker tables and layups to get a consistent rocker line.

[plummet]

yeah wood core does add some difficulty when you start to consider spring back. Not so bad when your shape doesn't have big concaves and rocker. Ramp the rocker and concave up and you have some mechanical challenges to over come. Thats why I use a combo of vac bag and mechanical press.

[downunder]

Foamcore lighter weaker design damaged more easily.
Wood core stronger heavier better impact resistance.

Agree, but you also need to take into account ease of fabrication.
Foam is so easy to work with, especially for a DIYer like me. Not just cutting and sanding, but springback on foam is negligible.
Wood, on the other hand, either requires a pre-shaped core or a fair amount of experimenting with rocker tables and layups to get a consistent rocker line.

Let's be fair and say "a consistent rocker line" changes at the moment it goes on the water Only super stiff boards would not change a rocker line.

I've found a foam crap to work with, particularly sanding dust...Bonding is an issue, the epoxy penetrates into to wood, not so into the foam.

D.

[rynhardt]

Let's be fair and say "a consistent rocker line" changes at the moment it goes on the water Only super stiff boards would not change a rocker line.

I've found a foam crap to work with, particularly sanding dust...Bonding is an issue, the epoxy penetrates into to wood, not so into the foam.

D.

okay, I'll call it a planned rocker line then

I've no experience with wood cores though, my comments are based on what issues I've seen other builders encounter.