I'm getting to a point where I will build my first Twin tip. I have built longboard skateboards and landboards before. So I already have the technology and experience with board building. I juts need to tweek my process.
Righto. I will explain my conditions and hopefully you can help me with the rocker, concave and flex.
I kite in the Wave capital of NZ. In fact its one of the best wave spots in the world. Conditions are chop and waves. usually head height or bigger waves. There's a great many days of 20+ knots and big seas. These are the conditions i want to build a TT for. For it will need to be more wave/chop orientated rather than a flat water water pop monster.
My thought process so far is to build a board that a board thats 134x42 more rounded at the tips that standard. Has a reasonable amount of flex for the chop. what i don't know is the amound of rocker i need and the amount of concave if any.
bambo is a great choice i am rite now making myself a raceboard and a twin tip of bambo as for your twintip concave smoothes out the ride however it also stiffens the board my choice is convex it smoothes out the ride also allows for a little more flex but more important it rolls from one side to another easier that is very important in the waves as for rocker i think about one and three quarter inch but i would suggest a little longer maybe 144 that might vprevent you from sticking the nose and going over thew front as for thickness use 2 one quarter inch peices and add an aditional one quarter peice the same shape as the foot pad for example look at the SU 2 board mine will be done in 2weeks and u can check it out good luck