Question on Longboard Fin Performance (single)

I have been experimenting with fins lately and have made some observations. I would like to know if any other people have come to the same conclusions. In order to not look like an Idiot, I will begin by just asking the questions and reading the answers to learn from the masters. I undersand that fins and rails work together so I guess the questions apply to those combinations as well. A list of shapes and their characteristics would be interesting as well. The catagories I am thinking of are Pivot, Hatchet, Dolphin, Sweep, Cutaway, etc… not necessarily different brands or models.

  1. Which fin shape has a tendency to bog down durning a turn? What causes this bog?

  2. Why do some fin shapes have a tendency to come loose while noseriding regardless of their size?

  3. Which fin shapes are faster/slower?

  4. How much does flex change a fin shapes characteristics?

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  1. How much does flex change a fin shapes characteristics?

words can not describe hom much flex changes a fin shapes charecteristics. A LOT!

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  1. Which fin shape has a tendency to bog down durning a turn? What causes this bog?

the more rake the fin has, the more it will project through a longer, arching turn; whereas a pivot fin will pivot off the tail (hence the name). however, rail shape at the tail is VERY important here. a hard edge downrail vs. soft 50/50 is night and day.

  1. Why do some fin shapes have a tendency to come loose while noseriding regardless of their size?

the focus here is surface area, and the distribution of that area. a 9.5" pivot fin with a sturdy base will hold the tail much better than a 10.5" cutaway or thin-tipped flex fin.

  1. Which fin shapes are faster/slower?

again, this is primarily about surface area. more surface area = more drag = less speed relative to the same board. a pivot fin will not project through turns, and we’ll lose speed on each change of direction. a fin with more rake will project through turns better, and a flex fin will have a nice little squirt as the board follows through on a turn.

  1. How much does flex change a fin shapes characteristics?

ginormously.