Hey! Yes, i think thicker wood would do the trick. I've got a 8mm wood core board that has very good flex. The thing is... 8mm + glass fiber is a bit on the heavy side... i'm not very particular on weight.. but... one has to admit that 8mm wood core + laminate makes for a pretty hefty board...
Keeping with the wood core solution, there is no reason why one can't make holes on the tips of the board, thus making it lighter. In order to prevent core / laminate "gluing" problems one could fill the holes with some kind of foam.
The "hole" solution has one problem... i made a CAD simulation of a 135 x 44 board with holes allllll over, and got a weight reduction of about 20%, regarding only the core. Thats great, to me at least...
The bottom line, for me, is... 8mm and up boards are perfect to get in to board building, and to make boards quickly. They are heavy, but ride great.
+/- 5mm wood core boards are WAY to thin and need heavy carbon / glass and / or tri ax. -> i wont be doing this again... the board is good... but its "special" board... on flat water i wish i had something with less flex...
The way to go, again, for me, are wood - foam constructions. Airex C70.71 is a great material... This way, i can have a full wood core, and then add 5 or 6mm of foam on top of that leaving the tips out. This makes a board with thin tips, that flex great, and a stiffer middle section.
The main concept here is that... the only thing that matters is moment of inertia, and that means thickness. The ticker the more resistant. By adding thickness one is making the laminate work less in "flection" and more in traction / compression. Keep in mind that we want traction, compression is not your friend.. but is unfortunately always present..
Just a quick note about my board, its nothing special really... just yellow paint and quick black vinyl. Just buy black stick on vinyl and print something of your PC, overlay the printed paper and your vinyl and cut with a x-acto knife
Very easy really... just happens to look good i think!