over the last 6 months or so one of my long time theories have been blown out of the water by experimenting with concave foils.
also im going to present a theory on vectored drag , ive had a lot of feed back from a heap of my team surfers and some longtime customers who surf real well , all up the following is a composite collection of comments and thoughts ,feedback and observations from a solid list of surfers …
the crew who have helped me on this are , the current west coast o/35s shortboard champ,the current west coast o/35s longboard champ,the current west coast o/40s shortboard champ,the current west coast o/40s longboard champ, the current west coast o/45s longboard champ,current open longboard national champion , current west coast and former national open longboard champion, plus a handful of other good surfers , mostly shortboarders with various styles and ages …
since ive been using the futures boxes and making my own foils to fit a few interesting things have happened . most of my team guys and some customers have managed to get hold of futures fins and make some interesting comparisons , plus comparing the concave fins ive been building…
there has been some contradicting feedback but the theory im putting up clearly explains the contradictions…
at this point its only theory , and till its excepted by a wider audience its still a theory ,
so ive posted some diagrams as well, most of the regular fin experts will know already the stuff ive written and drawn in the attachments but ive put some stuff in to help some of the laymen , so a few more crew could see how ive come to this conclusion…
im relying on the regular panel of experts to examine this lot and see whether you guys agree or not…pust it past theory…
templates aside this is just a comparison between concave foils and flatsided plus fuller foils…
in the shortboards there was a 50/50 split some said the futures were faster others said the fat foils were faster???
the guys who said futures were faster also said they could feel the extra drag from the fuller foils,
the crew who said the fat foils were faster said that futures didnt respond and nothing happened when they tried to turn , they sliped out easier , lost speed out the end of deep turns…
what ive personally observed is the futures concaves have less straight line drag , but increased turning drag , less hold , less responsiveness …
the guys who said they could feel the extra drag from fuller foils , had there boards set to take futures fins (future team guys, boxes set with less toe in )…
not one longboarder even rated slightly favourable any concave foil mine or futures …
all these comments start to make sense when we look at each fin as a vector force acting on the board and the magnitude of those vectors is depending on the camber of the foils and the toe in there set at …
so my basic theory is , a fat fin doesnt create extra drag by itself but 2 fat fins going in a straight line will cause drag because of opposing vector forces, as soon as there is the slightest angle of attack the fat foil has way less drag , more drive ,more hold,more turning power… all that enables the surfer to connect tighter turns closer together…
a thin fin has less straightline drag but increased drag everywhere else and prone to fail way ealier…
my previous theory that ive droped now , i use to beleive that as water went around the curved side of a fatter foil it created drag at that point , that if the foil got fatter the drag increased because the water had to go further around the curved side of the foil (like going over a steeper hill)…
but now i say the drag doesnt come from curved side it comes from the larger pressure difference , creating a larger opposing vector force between each side fin, because in reality set up right a fat foil will make your board go faster so it cant be the individual fins creating drag but the collective set if there not set right…
there are way more comments that crew have made … ill post the attachments see if they make sense and i can post the other comments and observations later …ok time to fry the brain…
regards
BERT