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Rocker and Concave

here you can exchange your experience and datas about your home build boards

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Rocker and Concave

Postby Richtw » Sun May 10, 2009 8:29 pm

How much rocker should I put in a board? And how much concave?

134 x 40 board for freestyle is what I am after - was thinking of 25 - 30mm rocker at the tip and 5mm of concave.... is this too harsh?


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Re: Rocker and Concave

Postby TomW » Mon May 11, 2009 3:35 am

Your best choice at first is to use a constant rocker ( a circle section as seen from side) of about 30-35 mm. 5mm concave is fine. I´d keep that constant along the board too to keep shape simple, but if you have good control over your shape, you may want to taper that out towards tips.

Bottom shapes that use "3 -step" rocker or more complex curvatures are really hard to make right. Add concave and it gets even more complex.

Outline shape has a big impact on performance too. You will be suprised how the shape of a 5mm rail and fins effect feeling too.

My suggestion is to start simple- move to more advance stuff as you learn how to build and ride. Change only one or 2 factors at a time.

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Re: Rocker and Concave

Postby scklandl » Wed Dec 16, 2009 3:55 pm

start at 5cm continuous rocker... never progressive rocker,

there are some basic principles that you can apply to make even 60-65mm rocker possible without sacrificing lowend or upwind, but you'll have to figure it out on your own

kiteboards dont need to be flat, in fact, flat boards plain suck

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Re: Rocker and Concave

Postby aeberl » Wed Dec 16, 2009 5:24 pm

There is no simple answer to your question...
Rocker, flex, concave and outline are all variables in the same equation and propper choice of values for them depend on intended use of the board.
First you need to define:
- Surface conditions: choppy, butter flat, salt or fresh water, etc, etc.
- Rider weight
- Riding style: board speed, riding edged or more flat, stance, etc.
- Which kite / windrange: C, SLE or bow, riding in sweet spot, underpowered or fully lit, line length, etc.
- Choice of footbads and straps
At the end, you will have to arrive at a compromize trading off some aspects of the board for the desired attributes.

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