I'm building my first board with 2 layers 6mm birch ply, top layer cut back to add flex at the tips and to reduce weight. I"m using west 105/206 epoxy to glue and seal and may use a layer of 6oz glass on the bottom and maybe the top too.? The goal is 25mm rocker with 6mm concave.
The size is 152x48 and I weigh 170lbs. I'm thinking that I will put two fins on one side so I can go with fins or without by switching sides of the board.
Anyway, my main questions is; what is the center to center spacing of standard kiteboard footpads/footstraps? Do different companies have different layouts or is it standard like snowboards?
I want to make my own pads for now and be able to upgrade easily in the future without changing or adding inserts.
Thanks to all posters who taught me a lot about boardbuilding, what a great resource. I will add photos and updates as things get further along!
I think that 12 mm plyboard would be a litle bit to rigid, regarding the cut back. At least try to use thinner ply on the top.
And I would suggest a smaller board for your weight, although it depends on the shape, but if you are doing a normal twin tip board I would suggest about 5 cm smaller board in both directions.
I don't quite understand what you mean with fin position. In TT boards you have pads/straps in duck position, so you have heel and toe side of the board (or you could say left and right tip) and it would be impossible to ride it switched. But it's totaly OK to have fins just on heelside, because those two are really effective and help you ride upwind.
The stance information, that companyes indicate is the measure between inner strap hole. It is usually between 40 and 50 cm. And the pad holes are arround 185 mm apart. It is recommended you position them slightly towards the toe side. Pads are rotated about 15 degrees.
mainly for kiting it is a 6.5" spread. but now cabrinha (maybe others) has a 6" spread (if you go with cab sync straps).
generally go with 6.5" and pretty well any plate and strap will work in any combo, not too sure of all these backless bindings tho. Flexi has a new one, Litewave, and cabrihna - don't know the spread on them.
so go 6.5" from center to center of the inserts.
if it is a light wind board you won't need all that concave. for fins, just have a hole drilled and screw them in. if you don't want them, take them out. it takes 2 seconds, really. and if you press it (however) make sure you add about 5-10 mm extra in rocker, b/c the plywood will spring back a touch afterwords.
pdkite is right, straps widths are not standard...yet. Most are 6.5, but many are 6. I recommend going to the shop and measuring a pair/brand you like and might buy in the future.
Consider skipping the 6oz glass; extra weight and extra labour. Sand the birch perfectly smooth and seal with your epoxy or spar urethane. I like using urethane, it dries perfectly smooth. Using west systems as a top coat I always end up with a few bumps that need to be sanded out.