toe in & inside foil

General Discussion
21

Some Notes on the ‘other’ value(s) of foil

In general, foiling is provides a degree of rigidity to fins, which is not there for flat or unfoiled fins. Simply rounded the leading edge, in order to achieve some degree of streamlining, has the added bonus of providing an extra bit of rigidity.

For those who enjoy drawing directly from Nature for inspiration, consider the fins of fish v aquatic mammals. Fish tend to use bones to support there fins, whereas, because their evolution was different, aquatic mammals tend to use other mechanisms, in addition to bone (but even then, quite differently from those of fish), to achieve a similar degree of rigidity in their fins. That is, they [aquatic mammals] would appear, in general, to rely more heavily on foil as a structural element in design. This being particularly true for dorsal and lateral fins. Yes, foiling is used in general, if only to streamline, however, the exact nature of its dynamic application, aside from structure would appear to vary significantly, even for creatures that move at comparable speeds and subject to comparable accelerations

In general, I don’t doubt the value of foil, it is at once offers a unique mechanical solution to providing rigidity to a structure, and at the same time offers the general benefit of streamlining. That it may than be used in other ways is also likely to be true, for both fish and aquatic mammals, and marine architects … and it would appear surfers.

Where does its application with regards to structure end and the secondary benefits begin? I don’t know. The question for me is that of its application in surfing. It has already been stated that surfers don’t go straight a lot, this being particularly true for current state of the sport. For me, this is a reasonable departure point.

kc

22

…no offence man,

I understand your point, may be I didnt explained it more

but this is like communism, all the guys who have been talking about that for years cannot accept that all their work and life go to a bucket…so insist until the end

-is like the rocker, it has more effect than other stuff in the final performance, but yes all the parts need to be matched like a whole

I can see lot of boards and very good riders in 3 to 6´ riding thrusters around the world using FCS G3 s, G5 s G 3000 s and knock off s (that have more flex), stiff Speeedfins without ANY change in final performance

also, I have been talkibg with most of the radical teenagers with that hardcore mags surf, and the guys say something like “…all feeling the same, etc” and still dont see any difference in final performance

the guys still can do slashbacks, reentries, aerials, long floaters, generate speed in 3´ waves, keeping that style all with the same effort

they dont feel anything different and I dont see any difference at all

and Im talking about what I m considering most important, like flex, stiffness, Height, etc…

so bullshits for me is blah bling about minimum changes when the sea in most cases is not near perfect

also some here talk a lot about design and then in other threads say that ride boards that…are like corks

I assume that these guys cannot surf properly well

may be with those corky bigger boards and fatty out of shape guys, these fellas feel (in the subconscious) that great changes occurs in their surf

23

Funny how fins seem to bring out a lot of emotion in people, and for good reason. There will always be those who just go surf and don’t really feel what’s going on under their feet. They just make whatever they ride work, and some just plain rip.

But there are others who have the ability to feel and understand the fine differences in shape and foil, and enjoy the challenge of finding what actually does work better, like Rich. I loved playing with fins too, and having played for years I know there is a noticable performance difference in both shape and foil, and don’t forget positioning.

Sure everything works, but many out there prefer something that works better.

24

…hello Wildy

please read again the other comments

Im only trying to say that, like you say too, there re may things before a minimum change in foil that people can or cannot feel

and like previous comments, thruster, bonzer, Twins set ups have more noticeable effect for everyone and a REAL change that an almost imperceptible 1/16" in foil curve (like I said previously in average 3 - 6´ WWide surf conditions)

25

Hey there Reverb, I pushed reply on your post but wasn’t particularly aiming at your comments.

Have to agree completely that the set-up (fin sizes, numbers and positions) will change things way more radically than a tiny change in foil.

Good thing is the incremental changes that then make there way into stock fins make the average board go better which makes everyone surf better and as a result feel better. Have more fun.

As for personal boards, always the quest to make them go better, and if a tweak works it’s all good.

26

…

I’ve learned a lot from this thread!

thanks guys

27

Hey, not so fast… Like what have you learned?

You’re the one taking the course… how about a few concluding arguments either way? Maybe a few crude calculations, order of magnitude kind of stuff, nothing precise but something that might bracket the impact of some of the ‘foil’ applications (as they relate to surfing) suggested here? You know, make some arguments so as to rule out a few things as being all that important, or do the converse.

Jeez… come on Hans… don’t leave a geek hanging. Yeah, I know in school the teachers are always saying that ‘questions’ are important, but in the end, its all about the answers - right or wrong. I’ve tried answering an exam question with a question - it didn’t work out well - it never works out well unless you’re a politician, or planning on become one… in which case, I guess this would be a good start?

kc