HWS Fin Guidance

General Discussion
1

Greetings, swaybots.

First, much thanks for all the knowledge and inspiration this forum has provided.

Long story short…got a bug up my ass to get a new board…like the Frye longfish

shapes and simultaneously discovered http://www.grainsurfboards.com and

http://www.grainsurf.com/forum/

Being that I’m a tightwad AND really enjoy making sawdust…I figured “what the heck?!”

So here we are…

that’s a 45" ruler next to it

the back third is (will be) dead flat with nice hard rails…blending up in to a slight concave that is most pronounce at the throat

in the first third.

the swallow is about 10.5" wide and a little over 6.5" deep…total length is about 7’8".

I may be making more work for myself than necessary, but I really want to put a bonzer 5 fin system in.

my reasoning is that:

  1. I really want to try teh bonzer

  2. if it sucks I can go tri

  3. if that sucks I can go single

  4. I might even be able to get a cool 2 or 4 fin configuration out of the deal

In short…I’m indecisive, but like the 5 box system at the very least for the wide array of fin combos I could try.

It’s for south bay LA el porto beach break to the pv cove rock reef with some north baja in for fun (but mostly beach break).

What do you say, swaylocks…your opinions and suggestions are greatly appreciated.

PS. might be looking for someone to glass this for me…if you’re in the LA/OC area…holler at me.

2

The 5 box system is great for switching from quad to thruster, but doesn’t work for a Bonzer. The placements are completely different. The standard for a quad is around 11" for front fins, and 5.5" for the rears. If you try to install bonzer side runners, the rear edge of your rear runners will be around 5 + inches from the tail. On a Bonzer shortboard, the rear edge of the rear runners is between 10.5" and 11", and the front runners are FORWARD of that. Not saying you can’t do it, just that if you do, and it rides weird, it would be sad if you came back here saying that Bonzers don’t work. I’ve mentioned it several times here but nobody seems to care. Maybe everyone is so giddy about having a fully convertable board that they don’t notice. Pics for reference…

Bonzer with rear runners @ 11"

Quad with rear fins @ 5.5"

A quick look at the Bonzer fin diagram makes it crystal clear.

3

what’s the guidance on the location of the center fin?

how far up from the crack should the box be?

4

5" and 1/2" to 5" and 3/4" from tips of swallow…

5

considering your previous statement regarding bonzer vs. quad…what about 7 boxes instead of 5 so

you can shift your fins up for bonzer, or back for quad/thruster?

where does the center rake get positioned for single/thruster/5 fin setups?

is there a variation on the fore/aft positioning of the center fin relative to the different side

fin placements?

6

The best thing about adjustable fins is just that…they’re adjustable. The Campbell bros. recommend 5 and 3/4 for the center fin, and a 1/4 inch overlap on all the sides. We always recommend to start at the shapers position, then make fine tuning adjustments from there to suit you, your board, or the waves. Or all of the above. 7 boxes sounds like a lot of boxes. Cheers Jim

7

is there shared positioning between a quad and a twin?

let’s say I wanted three options:

1: single

2: quad

3: twin

is this possible with 5 boxes?

I’m sure I can position the single independently, but I’m curious

if the twin/quad are mutually exclusive.

8

bump…

is there any overlap in terms of fin position for a quad and twin keel setup?

9
Quote:

bump…

is there any overlap in terms of fin position for a quad and twin keel setup?

Again, the positions are very different. Standard Twinnie is between 9" and 10" from tail. Standard quad - 11" and 5.5".

10

don’t know if this is what you’re looking for, but I have a board with lokbox side boxes and a single fin box in the middle. I get several different fin setups with this:

  1. twin fin (keel or twin)

  2. twin fin plus small trailer (need a small fin with a rear overhang)

  3. widow maker or 2 plus 1

  4. single

I find this is plenty of versatility to play around with. Any more and I’d probably spend too much time thinking about what set up to use and never actually get in the water.

Of course, this is on a 5’6" round tailed, round nosed board that’s nothing like your board, but I don’t see why it wouldn’t work with your shape as well.