Can someone explain to me the pros and cons of having a concave deck. And how it works into the construction of the board - example - depth of a concave? How far forward? How far back?
I’ve heard it being mentioned in several board descriptions, but I’ve never actually surf a board with one.
I really have no experience with concave decks, but logic might suffice. A concave deck decreases some volume in the middle of the board but keeps same volume in rails. Higher performance? It also puts your feet closer to the water rather than being x inches off the water, you are now x-concave inches from water. This could also add to performance. Also, you could hold really cool things in a deep concave. Maybe a six pack for surfdrinking competitions…ha.
That may be some of it. I believe that a major mactor may also be stiffness control. You see, curved surfaces are more resistant the bending than flat ones (although more prone to fracture).
bert talks about deck concave enabling rail to rail flex resulting in dynamic bottom contours… DanB and Bert have had several open discussions about this…
archive search option has changed so I can’t find the threads right now. One of the threads is something like “Where is Flex Important”.
To sumarize… Bert has talked about the concave deck and flat bottom resulting in a concave bottom when loaded and flat bottom when not under load. flat bottom board for paddling while concave bottom for hard bottom turns…
Here’s what Bert said from the Flex important thread:
Quote:
whats the benifit of a concave on the bottom of our board ??
when do we use the concave ??
why do traditional p/u p/e boards go better with concave bottoms ??
because p/u boards have there rail line flex off in turns , a flat bottom turns into a v bottom so to speak and will lose a certain projection out of a turn , add concave to the tail and it ends up flat under load on the inside rail but still releasing water nicely on the outside rail …problem solved !!!
not entirely , you still have to deal with the concave when your not using it …
while trimming on the flat you have a bottom curve that really only wants to work best when on the rail hard …
a different form of construction allows shapes to be explored not possible with p/u p/e …
get some paper to form a concave like it was a concave deck , now bend it in the middle as if you were standing on your deck and the nose and tail was being supported …
what shape does it go into???
concave deck flat bottom surfboards …
fast when flat , then when you load into a turn and flex the board the bottom starts to concave ??
yep flat when you need it and then concaved when you need it …
ouch …
if something changes when we exert a force on it , might as well design it in such a way that the change will help us not hinder us …