Bonzer / Quad

Im in the process of making a short and wide traditional fish come bonzer come quad.

Can someone help with fin placement for

(i) Bonzer 3

(ii) Quad thruster fins

6’1" long

17 1/2 nose

22 1/2"wide

17 1/4" tail

12" pod - diamond tail

WP 4-6" forward

Thought I would shape it as if I was making a bonzer then at the last minute apply well canted quad fin setup.

Any help on fin placement would be great.

Sweet looking board…I’m planning a quad like this, have the EPS, making the blank this weekend.

hey thanks, yeah I cant decide on fin setup. Anyone have a feeling on BONZER or QUAD positioning?

The waves are not as down the line here as I would like, but it should be a great travel board. I can think of a couple of points that I could crank up the speed on this one.

Also will be my first glassing attempt, fingers crossed.

Quote:

Im in the process of making a short and wide traditional fish come bonzer come quad.

Can someone help with fin placement for

(i) Bonzer 3

(ii) Quad thruster fins

6’1" long

17 1/2 nose

22 1/2"wide

17 1/4" tail

12" pod - diamond tail

WP 4-6" forward

Thought I would shape it as if I was making a bonzer then at the last minute apply well canted quad fin setup.

Any help on fin placement would be great.

hi trim !

so , just to clarify …

it’s going to be a fairly stubbie diamond tail , shaped as a bonzer 3 fin , yes ?

will you be putting in the DEEP double concaves that design featured ?

"then at the last minute apply well canted quad fin setup. "

so, extra plugs / boxes to allow the quad option …is that the idea ?

[in effect , allowing SEVEN different fin placement options?]

I just needed to check I read this right .

You will see I have “resurrected” a thread of ZoSurf’s [Super stoked on Swaylocks’ ], where he had a similar plan shape with multi-fin options , which I trust may hopefully be helpful ?

For you to be able to ride your intended design as a quad only , you would obviously need removable bonzer3 runners…boxed or plugged. Can be done. But the deep double concaves for the bonzer design , combined with four fins , I don’t know about . [Was it Mike Eaton that did that design ?]

I hope you go ahead with this …

it is certainly a fin setup I have not contemplated on my boards [ at least, not with the deep bonzer concaves]

Also, as I mentioned in my ‘p.m.’ to you , there are some useful quad fin templates and positioning recommendations on ‘oldy’s’ thread ‘quad fin templates’ , recently.

okay , I hope this is useful to you mate [and that I interpreted what you wrote correctly?]

cheers !

ben chipper

I can’t see anything inherently troubling with a deep double concave and quad fins. The depth of the quads replaces the depth of the center fin on the bonzer, and yet the fins are close to the same positioning of the Bonzer runners…

Kia ora Trim King!

The Bonzer bottom contours shouldn’t be an issue for a quad set up, at least not in my experience. My quads all have single to double concaves, though not as deep as my Bonzer.

Re placement, on a board that size I’d go:

Rear fins: 5 1/2" up, 1 1/2" in from rail, 1/8" toe in, 5dgrs cant. Double foiled.

Front fins: 11" up, 1 3/8" in, 1/4" toe in, 7dgrs cant. Single foiled.

Some like the feel of single foiled rear fins, and they do give nice drive and turn well, but I find the double foils make for smoother turn linkage.

The toe in could also be laid out pointing a straight edge from the trailing edge dot to a point a few inches either side of the nose (3" if you want it to fly smoothly down the line, 1 - 1 1/2" or so if you want more pivot type turns).

Cheers

Maz

hey Maz thanks heaps for such specific advice.

also Chipper, you really hit the spot. thanks mate.

So I guess I am making a QUADZER. I reckon we are entering a time of surfing where permutations will be explored. The modern shortboard is now evolving in small ways difficult to detect. This movement will undoubtedly spawn new breeds of fun designs.

Anyone who wants to post their Quad fishes etc go right ahead on this thread.

Hey guys,

Well this board is almost ready for fin installation.

It has been suggested that I should just go with a 2+1 (single fin plus one set of side fins).

If I place a box at about 5.5" from tail, any ideas on the side fin placement?

Many thanks!

Anyone willing to have a stab at the side fin dimensions?

Got to do the install tomorrow!!

HELP!

what about 14" for the sides and 6 inch for the box?

or maybe 5.5"for the box and 11"for the sides?

I really have no idea here?

Howdy TK,

I’d keep the side fins up around 13.5-14"–the tail’s pretty wide, so those fins, combined with the widepoint forward, can be more forward. The fin is usually in the front 1/3 of the box, so a box at 5 to 5.5" sounds right in there. You might want to consider a longer center fin than usual for a 2+1 to compensate for that tail width.

Jamie

trim_king: i really like the look of your stub-bullet template. i look forward to seeing the final shape.

“ZoSurf’s … a similar plan shape with multi-fin options …”

yours

zosurf’s

… I post this , just to help you with ‘pre-visualization’ , hopefully ?

cheers ,

ben


Hey guys. Many thanks for your help and support. I thought I would explain my thinking on the boards design. I have also had some advice from some guys in the industry so its a mix of ideas.

The template is wide with a super wide tail and pod.

To balance this, I added a generous single concave starting at about 12inches from nose and running out the tail.

I also shaped a pretty hard tucked edge all the way to the nose.

I am 6ft and 97kg so this board is going to be loose for me, its a game of stiffen the planshape up I reckon.

The rocker is pretty low, I think its about 4 in the nose and 1.5 in the tail (inches).

Today I drilled the FCS holes with about 1/8" toe for DRIVE. They are at 14", 1 1/4" from the rail.

Installed the box at 5.5" so I have some options.

Chipper has made a great suggestion - make some bonzer skegs to fit the FCS sides. This will definitely stiffen and add drive for sure. Thanks for all your help CHIP!!

I have made one OOPS from rushing things this arvo - drilled one FCS hole way off the mark (“F%#K!!!”). I have already patched it, but am bummed about the blemmish. The boards for me so no major worries.

Sorry no pics, I will start from now on this one.

So scared about sanding the bugger! Cant wait till I get to the polish bit!