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Originally Posted by atapene  ...mmmm. obviously those assumptions are pretty debateable duck without some pretty detailed scientific testing.... but i do agree you have to have a well-fitting fin. |
How about just a little insight and common sense.
Most of the big bladed fins work good for deep slow kicks, usually good for surfacing from 30+ meters. I may be wrong here, and perhaps a Physics Major could explain it better, but I believe fins are designed to maximize the result at a particular cadence which is related to the kick range, length of blade, and flexibility of the material. Any lesser cadence and you get less push, any more and you lose the designed flow resulting in less push for the effort (possibly caused by the formation of eddys where you don't want them which would slow you down). Smaller bladed fins are designed for faster cadence using the same relations. Somewhere in the middle is more than likely the optimum. People's incorrect thinking and willingness to pass it along without question is what skews most hockey players' opinion. You probably heard from someone during your early years that you needed a bigger fin. They were probably told the same thing. And when you put on the bigger fin you probably went faster so you bought into it. I'd guess you went from something wimpy to something decent though. But the fact is you need one that fits you. Not just your foot, but your style of kick, your cadence, and the range of your kick.
To validate this all you have to do is look at boats. If that were not true, propellers for boats would all be the same. But they have different diameters and pitches. The simple reason for this is boats are designed different from one another. A different waterline, a v-hull or flat-bottom, different weight, motor size (power and rpm), just to mention a few. Just like people no one is exactly the same (except maybe twins). If you want to improve the speed of your boat you can't simply put a bigger prop on it and be done. A bigger prop will put more resistence on the motor bogging it down a bit. If that motor can't spin the prop fast enough for the boat to plane then you won't be faster. When you match your motor with the right size and pitch of your prop you will maximize your speed.
On the evidence level I have cut off the tips of old Alas and they are faster. So have others, and some have done so with Twarons and Quatros with the same results. Just a couple of inches. Perhaps they were designed for a slower cadence at the length which they were produced. Or perhaps they had worn out so much that they stopped getting the proper shape for the water to flow correctly. Or perhaps my motor is not big enough for them. Or perhaps the range of my kick is too shallow. Or maybe it's a combination of any of the above. Or something else. But the same foot pocket with a smaller blade was faster.