interesting !!!!! well done , i hope it goes nice for you.

Those runners will have a braking action unfortunately, due to the fact that they are curved inward and toed out.

RoyStuart said..
Those runners will have a braking action unfortunately, due to the fact that they are curved inward and toed out.

how do you know ?

maybe...when the water cannot go anywhere but down....it will give me lift....just maybe.............pushing the envelope too far....is the only way your going to know...if you have pushed it far enough

just give it a run with the kite mate ...sorts it out in a couple of mins as you know!

I would think a smaller centre fin- well maybe

laceys lane said..
I would think a smaller centre fin- well maybe

dunno mate...we will see...it will be an interesting day at the beach

RoyStuart said..
Agreed it should lift the tail, it will be interesting to see how it goes.

the water shooting off the outside rail is kind of starting to take that shape....this is a quad fin set up and you can see the water is squirting off the outside fins...it sure as hell is not slowing the board down....I am anticipating that it all will all flow through the turns from rail to rail....the waters angle of attack is changing all the time so I'm thinking the curvature will not be a big concern as the blades are not deep enough

arkgee said..

laceys lane said..
I would think a smaller centre fin- well maybe

dunno mate...we will see...it will be an interesting day at the beach

That fin second from the left is is a nice side shape ! similar to a fin i had in a knee board once .

+1

Looks like a board made for figure 8's in the pocket...not for going straight gunning for the shoulder

vanders1 said..

here is a diamond in the rough for you V

Cheers mate, looking good.

I think I'll actually get you to supply one of those Fluid Flex fins with it after all, they look good.

Nice "SPOT"

arkgee said..

hey ricardo...my last post pretty much answers my thoughts....what you described is the theory the bonza design was based on...I think it was supposed to work like a ventury....compress the water flow then release it...I dabbled in bonzas for awhile, though I never liked them much.

The venturi was for 30 years what the Campbell Bros thought accurately described the principle behind their bonzer setup... but it wasn't.

I pointed this out to them ten years ago and was banned from surfermag ( temporarily as it turned out) for doing so, you'll notice however that they no longer mention the venturi principle on their site.

The bottom line is that the venturi is a closed system, the surfboard hull is not.

Compressing and/or constricting water flow will always create more drag, the idea that by constricting the flow one speeds the water up is a complete myth.

The bottom line is that disturbing the water in any way slows the board down, we have no choice but to do so but keeping it to a minimum promotes speed.

Your inwards curved runners are definitely going to make the board slower than the same board would be without them, sorry but that can't be helped.

More rail, and deeper... just saying.... but it's hardly relevant to the physics of constricted flow...

good bottom turn Roy