Fin Idea to increase durability and depth options

I just barely thought of this idea. Hopefully it does not sound too crazy. I am sure that it will be more expensive and difficult to make though.

problem with current designs: I have seen fins crack and break where the screws go through the fins because the material is soo much thinner there

I was thinking that the screws could instead become shafts that are A PART of the fin. They could be machined as all one piece with screw threads on the top. The fin's shafts could be inserted up through the bottom of the board and then bolts could secure it from on top.

the attached illustration: i did a quick picture to illustrate this. I know the fin is huge and looks more like an old school fin, but just look at it for the idea. I colored the fin blue to emphasize that it and the shafts are all ONE piece. and the two little eyeball-looking things are the bolts up top.



advantages i see:
1. the fins would be less likely to break without pre-made holes weakening the body
2. with this design more shallower fin depths that were thought to be unachievable could be made, because the bolt no longer has to screw into the fin. Thinner fins could even be made (ouch)
3. this is more of re-emphasis of 1 AND 2. the fins would be more slider friendly

disadvantages i see:
1. the bolt securing the fin on the top of the board would have to be bigger, potentially creating a bit of an eye-sore
2. more expensive and harder to make
3. less universal of a fin design. it would be more specific to one brand of board


tell me what you think?

(disclaimer: i am no expert when it comes to manufacturing)

great idea man, its a wonder it hasn't been done already.

It kind of has been done. There may be more examples, but the CWB Prodigy fins come to mind.

These fins had threaded shafts sitting on top of them. Short screws went through the board and into the threaded shaft. A little different that what you are suggesting, but close.

Take off the fins and learn to edge.

I'd think if you hit something that would break a normal fin off with your fins it could damage the board quite a bit more. I'd rather replace fins than a board.

Or the whole world could start using CDI fins. Good luck breaking them. The 7 years we have been in business we have only seen one break. After analyzing it we determined it was a flaw in the casting.

Actually Jeremy we have looked at this style before and with plastic fins it isn't too bad of an idea. With the aluminum fins and the wider base of our fins it is not needed. Plus the wider bases helps keep the board from getting damaged as Dan pointed out.

Skiing made me board,
Lyle
Chrome Dome
www.cdifins.com

(Message edited by sunsport on October 01, 2008)

Lyle would those fins fit on a SS? I'm getting some of the new fins from SS that aren't supposed to slip, but like the look of the C. Wright fin

Hey Josh,
You know Slingshot was using a non-standard hole size last year. Not sure if they standardized it to 1/4" or not. Do you know what size the holes are on your board and the spacing of them?

Skiing made me board,
Lyle
Chrome Dome
www.cdifins.com

Ride finless!

The screws are steel, and the fins are usually plastic or aluminum. In your design, the whole fin would have to be steel, making it heavier.

Also, even though it is one piece, you would have stress concentrations where the protrusions meet the bigger part of the fin. Now, the protrusions will snap off instead of having the screw split the fin's hole open. It might not be stronger, just fail in a different way.

I have a set of fins like Jeremy is describing. I don't know what board they came from, but somebody in our crew bought a Cassette wakeskate and somebody had retrofit these fins on it. They now are on one of the wakesurfers. The fins were big, so I did some custom shaping on them. So, it has been done before, and they work fine for our application, but we aren't hitting sliders on a wakesurfer either.

If you make the fins to strong then you are going to be breaking boards instead of fins. I see that as a much bigger problem.

Damn fine rendering of a fin with MSPaint but why are there two Penn State helmets floating over it?