My Quad Placement, Tell me what you think.

General Discussion
1

G’day!

Well I’ve read a lot about quads recently and until now i wasnt really going to join the craze/jump on the bandwagon due to a truthful comment i read from a shaper i respect alot.

However, I feel like i’m being a toolkit by ignoring quads and dont want to be like a lot of guys were when simon’s thruster came out. I guess what fueled my curiosity and my (must do it attitude) was when I saw a guy with a local shapers board as a quad down in my quiet little home town of Avoca. If the craze is hitting here i wanna be among the first to get on it. Also I rode a quad many years back in Bali and had a blast on it! the board i’m reffering to was a 1980s Japanese swallow tail quad that was pretty beat up.

Anyway I have two boards I plan to convert. The first is a beat up 80s thruster with back fin box to remove the back fin. I’m chosing to do this board first to see if A) i’ve got enough skills to do a good job of putting in fcs plugs and B) to see if i like quads. The other board is my poly thruster with fcs plugs from a couple of years back.

in saying this it is possible i may not do this at all. lol.

So what do you think about my fin placement.

The front fins are 11" up at the trailing edge.

I was thinking of putting the back fins 5 1/2" up the board and 1 5/8 - 1 3/4" from the rail.

Would this be good for a quad fin? I’ve read the Mckee formula isnt prefered by many and i thought the back fins look to far in off the rail. I also wanted the back fins to be able to turn tight in the curl but want to maintain a little bit of the feeling of having a cluster of fins to act as more of a single fin if you know what i mean.

Feedback much apreciated.

Cheers!

Josh.

Also, Can you still get the old fcs plugs or are they all the new red and blue ones? and to the aussies, where abouts on the central coast of nsw can you get fcs plugs or is there an online retailer?

Cheers again.

2

The boards…

3

I’ve only been making quads for a little while but, with the experimenting I’ve done, I find the rear fins on the McKee formula too far off the rail, (for smaller waves at least). His formula seems very drivey though so in big stuff could well be a lot better. Your placement ideas seem sound, try it, it’s a good starting point. Once you see how it goes you can always alter your set up to suit you. Nothing like a bit of experimentation.

4

Thank you sparksbrand! Very much appreciated.

5

On my last quad I felt that having the back fins less than 1 1/2" form the rail made it harder to get the board on rail. I always felt like when i did a bottom turn or a cutback I wasn’t getting the board on rail (carving). It seemed like the fins were doing too much of the work. When I added the middle fin, it surfed top to bottom a little better. I’m about to shape a 6’2" x 20 1/4 quad and I’m planning on bringing the two back fins toward the tail a little more, and closer to the stringer, similar to the formula that josh is talking about. My Idea is that I can hopefully achive a little bit of thuster pivit with some quad drive.

I’ll post some pics as soon as its done. So far I have a 6’5" USblank about to be shaped.

6

Just for shits and giggles, here’s some info I posted on my old Channel Islands quad to show us how they did them in the past…:

Al Merrick Quad #10957 “Al shape”

6’2" x 12 1/2 x 20 1/2 x 15 1/2 x 2 7/8

Front Fins are single foil

Between front edge of front fins: 10 5/8

Between rear edge of front fins: 11 1/8"

Front of front fin to tail: 14 1/2"

Back of front fin to tail: 9 3/4"

Fin base: 4 5/8" or so

Fin height: 5"

Front of fins to rail: 2 1/2"

Back of front fin to rail: 3/4" or 7/8" or so

Rear Fins are also single foil

Between front edge of rear fins: 7 3/4"

Between back edge of rear fins: 8" (thus very slight toe)

Front of rear fin to tail: 8 1/2"

Back of rear fin to tail: 4 7/8"

Fin base: 3 1/4" or so

Fin height: 4"

Front edge of rear fin to rail: 1 3/4"

Rear edge of rear fin to rail: 1/2" at most

From leading edge of front fin to front leading edge of back fin - roughly 6 1/2 inches. (same as the modern remake).

Cant is very slight and the toe of front fins isn’t a lot either (do not aim at the nose tip) and toe of rear set is very slight. Rails are very full, and carry an edge all the way to the nose like a 70’s board (i.e. it doesn’t have soft rails up front).

7

Howdy again,

Just adding my two cents worth on this old forum…in saying that, in 2004 I didn’t have the tail fin positioning in relation to tail width formula on the website… and I wasn’t expecting everyone to start making slabby fish boards. I had personally steered away from there… So my fixed position at the time for standard width short-boards, which was only food for thought and not gospel for the whole range of tail widths, was being place on 20" plus wide boards and obviously too narrow, thus the above comments.

Due to this phenomenon I had to give more exact details in a new formula so as make it all clearer… Many have forged their own paths in the meanwhile which is great… Thinking caps on!

Cheers.

8

Good to know, McKee. Thanks for sharing your knowledge here.