Sorting Your Fins
I'm always getting customers asking me which are the right fins for their boards. And to be honest, the answer is I really can't tell them....
And that really doesn't sound right, does it? After all I designed the board, so I should know which fins should work for everything I've designed, right?
Actually, no.... and here's why...
How a board feels to a surfer is a very personal thing. Some surfers prefer a very solid feeling board with lots of carve and drive, while other surfers want a lighter feeling board with more drift and slide in the turns. Some surfers want lots of drive off the the bottom of the wave, but have it light and whippy off the top, etc, etc...
And then factor in the type of waves that the surfer is riding. Maybe it's a softer, lighter, tropical water style wave that's going to prefer a softer more flexible fin or maybe it's a thick, slabbing cold water ledge that's going to need a stiffer fin. Maybe it's a long walled up point break, where you're going to be doing long,drawn out turns maybe it's a tight, punchy shorebreak that's going to need very quick, tight turns. The variety of waves is a massive equation.
And then once you factored all these aspects in, you still have the subtle personal feeling that a rider likes to feel under his feet. Just like snowflakes you can bet that every surfer has a slightly different expectation of how they'd like their board to feel under their feet.
So how do you work out the right fins for the board? The same way that all surfboards have been designed and evolved over the decades... good old trial and error.
Welcome to the world of surfboard design!
The Solution
But before you go throwing our hands in the air in exasperation, as I have done a million times over the last 40 odd years, here's some hard earned knowledge and tips to help you find your way through the maze of surfboard fin design.
Overall Fin Area
The overall fin area is generally going to affect the drift of your fin. Not enough fin area and you'll feel the board drifting too much thru the turns. Too much fin area and the board will tend to be grabby in the turns and can even cause your board to skip out of that water a little. This one is critical to get right and once you do, you're 90% there.
Fin Base
In general, your going to feel the affect of the fin base mostly on your bottom turn. Want more drive, get a longer base fin. Want a little more drift in your bottom turn? Try reducing the base of your fin. This is not such a critical issue, as more of a fine tuning area.
Fin Tip
You're going to tend to notice the affect of your fin tip mostly in your top turns. Want lots of drive off the top? Go for a larger, stiffer fin tip. Want more whip off the top? Try a fin with a finer tip. Like fin base this is more of a fine tuning area.
Fin Ratio
With multi fin front and rear set ups such as quads or thrusters, the balance of the front and back fins will affect how the board feels. If the board is tending to understeer and nor come around through turns easily enough try reducing the size of your rear fin(s). Conversely if your board is oversteering and coming around too quickly and too easily try increasing the size of your rear fin(s). This is a fairly important one to get right as you're setting up the understeer/oversteer balance of your board. But note the while fins can help balance this, they won't be able to overcome a board design the excessively under or over steers.
Fin Rake
The rake of the fin is how much the very rear tip of the fin overhangs behind the base of the fin. More rake is generally going to project the board further through turns while a more upright fin will allow easier pivoting style turns. Most fins are fairly balance in this department these days, but still it's a factor to consider when choosing a new set.
Fin Flex
The flex of the fin is quite a significant factor. A fin thats too flexible will tend to drift excessively thru turns and produce a delayed whip effect out of the turn, while a stiff fin can feel clumsy and unresponsive. This again is a reasonably important aspect of fin design and while most fins these days are fairly balanced in the flex department, it's still worth paying attention to.
Getting the Balance Just Right
And so how do you get the balance just right for your board, to get your board to surf the way you want it to feel, and to suit the waves you ride it in? Yep! You guessed it... trial and error!
My advice? Start with fins you know, and work from there. Once you get it sorted for that board, take a photo to record that setup, because rocking up to pumping surf with your magic board and then not remembering exactly which fins are the right ones is a frustrating feeling...and I know, because I've done it!
And getting it wrong can be extremely frustrating, because it's going to rob you of having a good surf, and trust me, as a surfboard designer, I've experienced that way too many times for my liking, but remember, at the end of the day, you're still sitting in the ocean catching waves and not sitting in a boring office or an endless stream of peak hour traffic!
Good luck!