Isaac Wood's Blog: January 2010

There has been a lot of talk about fin's lately. Whenever the surf comes up everyone seems to be lost on the placement of their fin's. It's a lot easier when the surf gets small to not mess with the fin's because there isn't enough speed to really utilize the fin. However, when the surf gets big a common thing I see is people sliding their fin's back. Although the theory is true on some single fin's, most of the time when the center fin is in the correct position the waves can be big or small and the board will work and turn well without ever moving it. I cant ever just say a fin set up is right or wrong because everyone has their own style. My brother Micah and I can ride the same board but need totally different fin setups to match our style on that board. I know for a fact what works for him does not work for me which is why this blog is more about the characteristics of small and big fins as well as a small insight on how to set up your fins so that hopefully you can get a feel for what works for you...

Depending on a surfers style the side fins usually become a pivot point for the rear fin to carve around. Side fins can really change the way a board drives and reacts out of turns.

How to find which side fins work for you?
A good way to find out which better suits your style, if you have smaller side fins add larger side fins to the set up that you are currently riding... ride it...Get a feel for how this rides. Depending on center fin size, the board may feel like there is too much fin (almost like a parachute effect). This is good, because now you can move to a smaller center fin, no more then 1/2 an inch at a time. Shortening the center fin allows both side and rear fins to release easier, but not drag as much as the larger center fin.

Characteristics of a smaller fins
This usually makes the board turn fast, have faster bursts of speed and livelier feel. Although, some of the benefits of small fins can be faster with turns and more forgiving the down falls can be slower in straight lines or trying to maintain speed through the flat sections.

Characteristics of large side fins or lack of center fin
If the board feels fast down the line but doesn't turn well, this may be from side fins that are too large and creating the main drive and not allowing the rear fin to pivot around them. For instance tipping over on cut backs, not gaining speed on turns or not transition smoothly from rail to rail. Most of these characteristics of a board can usually be blamed on not enough Fin either center, sides or a combination of both.

Characteristics of a Large center fin.
Unfortunately, fins can also go the other way by the center fin being so big that the side fins just drag along. The center fin then becomes the speed...not the two fins working together. A board that feels directional can also be caused by the side fins not being large enough to create drive. because the center fin never breaks loose so the board becomes tipsy and less forgiving but can have a more stable feel, drive smoother and faster as well as noseride better. Drive is what is sometimes lost when moving the fin back. To much center fin may be fast and drive well, but it isnt very forgiving and tends to have a tipsy feel when turning.

The way I find side fins is first find my center fin placement using the method from my previous blog (by marking the center fin 1-5). After the best spot is found remove the side fins and replace with bigger fin's. What this will do, is change the way the 3 fins break in the water. It will cause the side fins to be deeper in the water, causing drive off the rail when turning. If the fin is too small the board may loose all drive and feel dead when turning.

I like to have 3 of the same size fin for a short board feel on my 9'0" comp boards. Although lacking on stability, the boards have quick little bursts of speed and snappy exits out of turns and an overall more forgiving feel when doing 'off-the-lips'.

On my 9'2' to 9'4" (my bigger boards) I like to have 2 1/2 inch side fin's with a 7 1/2 to 8" center fin. This gives me the feeling of a single fin while noseriding, but the drive and turning of a shorter longboard. Anything over 9'6" tends to loose the feel of a tri-fin due to the length and weight of the board. The tri-fin set up still works, but the size of the 3 fin's together become way more critical to the way the board reacts and feels.

I have found with my single and tri-fins...the bigger the base on the center fin, the more drive can be generated. A drawback to having a large base is turning gets drawn out, so it is good to find a fair medium of flex, base and length. The next blog will explain base and flex and how each effects the way each fin works and why.