Tardy thanks for taking an interest in this post and giving your input, great to see you had some success in modifying your fin as its not easy getting the foil rite, my guess is you got the foil rite rather than just thinning the fin down
The smallest fin is a bit wide at the base but no wider than your MXR WEED , the difference is the fin is wider further up the fin and narrower from midway to the tip, the chord at the base of the fin has been lengthened with a shallow foil similar to your normal delta, i'm not qualified to say if the thickness slows the fin down or gives the fin early lift but i'm happy doing around 33knts, so all I need is another 2knts and I have reached my goal
the answer to your question about the tip breaking off , my concern isn't the tip but the back of the fin is sitting on the board , if the fin hits a solid object it will smash the back of the board, also you can't use carbon at the tip of these fins because the carbon is to brittle, if you drop a forward boxed fin you can bet it will smash the tip

some interesting info .The fin i messed with or thinned out was a select .scouts honour it was 25% faster
on all points ...it still was a thick mother .

i do notice this on my SUP fins on waves ,the thin FCS fins are a lot faster than the naish .standards .which have thicker walls .But it sounds like you've got it right first time with good speed . they even look good .

I Guess thats why its hard to get carbon fins now ,being fragile .

i was too useless to make one so i did buy a delta ultra XT 22.i like it .

I'm sure you'll hit your 35 knots and beyond .

I'm also aiming for this.

looks like some serious dredging there Dezza

Tardy said..
Hey keef,nice job mate .
just noticed the fin is quite thick at the base ,just wonder if this would effect your speed .

Tardy i'm not sure if the thickness of the fin makes a lot of difference except for different wind conditions , e,g I used the same 18cm fin Jetlag managed to get 40nts a few days earlier with a 6.2mt sail in 25nt wind , I was getting lifted on the same fin with a 4.6 sail 30 to 35knts , my guess is if you have the rite foil for the wind conditions you can have the same fin thick or thin, I guess it's a bit like using the same size sail with more or less down haul,=the same size sail
keep up the good work your fin mods look great

Tardy said..


Cheer keef.
your on the money with those speeds ,
It must be rewarding to make your own fins then get a 40.
you must be stoked.

Tardy I made that particular fin a few years back and before the production guys started make small weedies, I have only managed 37nts but other guys have done 40nts , I have only made or modified boards or fins the production guys have done then come up with my version , the board in my avatar is a classic, example Leo Rockfingrers was knocking out 42+nts at primbee on that board and showing the budgi guys where to sail, a pioneer and a legend of speed sailing in NSW
getting back to the fin in this post , I'm not sure if its the answer as the last time I used it i was picking up weed when starting, my test pilot is back from the slalom nationals Green Island so hopefully we can get some wind and some modifications