Select slalom fins (windsurf): Defective fin heads of the Select RS7 and SL7 slalom fins.

Defective Select RS7 and SL7 fins.

Performance wise I'm a big fan of Select slalom fins (the SL7 and RS7 series), and consequently I have a large quiver of those fins for my slalom boards (Tabou Manta 85, 79, 74 and Rocket 115 and 95). I've tried other slalom fins, but until now I haven't found the "bite" of the SL7 and the RS7 anywhere else – allowing me to ride my Tabou slalom boards with comparably small fins.

However, lately my SL7's and RS7's have started falling apart at a faster rate than "usual". The first sign of the fins giving up is a widening of the cracks between the (plastic?) fin head and the foil, making the fin somewhat "rubber-like" to sail. I mean - after just a couple of hours of sailing ALL of my Select SL7’s and RS7’s have developed small cracks between head and foil (if you pull the tip of the fins after sailing you can always see water being squeezed out), but here I’m talking about cracks that are wide open without the fins being pulled or pushed.

If you don't notice this early sign of failure and continue sailing, the fins pretty soon start to delaminate along the foils (probably because of the lack of support from the fin head?). The signs of a delaminated SL7 or RS7 are of course low speed and lots of spin-outs.

To show the defects more clearly the fins in the pictures below are pushed moderately to one side or the other. However, the pushing force doesn't come close to imitate the force exercised when actually sailing.

The log says that the SL7 39 cm fin has been used 13 hours (with a Tabou Manta 74), the RS7 41 fin has been used 7 hours (with a Tabou Manta 74), and the RS7 45 cm fin has been used 9 hours (with a Tabou Manta 85).

The fins have probably been defective a short while before the failures were recognized.

At my place for years we've known that the lower priced race fins from Select aren't the strongest around, and that eventually they break down around the fin heads. But the short lifespan indicated here I find a little alarming (my wife can't earn money in the rate that my fins need to be replaced), and a question with a link to this page and the pictures below was sent to Select-Hydrofoils in the middle of September ("I've noticed that you produce the SL7 and the RS7 fins in another and more costly edition (the S07 and R07 fins). Are those fins different from the ordinary SL7's and RS7's only in the shaping process - or are they also stronger and have a longer life span?").

Select-Hydrofoils haven't answered yet.

Update:

Unfortunately, latest experiences tell that the fin head problem is NOT confined to the (now discontinued) SL7/RS7 series. Also the (ongoing) S07 and the S10 series show strong evidence of bad quality fin heads, and the clear signs of this often starts from about 10 hours of usage.

What to do if you have a large quantity of Select slalom/race fins? Well, tentatively I've simply started to strengthen ALL my Select slalom/race fins from day 1 - in an attemt to widen their life span. If this simple method functions I don't know yet - I'll let you know.

You can see the try here.

Click the picture to enlarge.