Performance longboard - twin fin question.

One of my upcoming builds is going to be a 9'0 longboard for myself;

it's going to be a 2 plus one , but one of the main reasons I build my own boards, is to try new ( for me ) stuff -

so I thought for a giggle and to spice up my life , that I'd give myself the option of riding it as a twin ( or more likely a twin plus trailer).

So , fin placement ? Depends on the rocker and planshape I hear you say.

Well I'll be upfront here and say it's going to be a knockoff of a friend's board ( which is a popular model from one of the leading lights in the longboard field) , so those factors are set in stone.

The sidebites are at 17 " , so I'd say the twin fins will need to be considerably further back than that .

Yes I've trawled the archives , the whole web actually and there's nothing too concrete there -

Aviso / Lance Collins do a twin LB , as do SR , Bob Pearson's well known for it , and of course G Griffin's done a few.

There's also the Infinity Cluster

So has anyone owned ridden checked out one of these and can give me some measurements ?

Or any of you shapers build any ?

Cheers guys

feel free to respond by pm if you like.


edited (by Huck) to add...(Infinity cluster)

I saw one this week.  it was set up as a straight twinnie.  with a channel between them. the fins half way between the rail and stringer. no cant or toe.

apart from the channel, it was identical to the only other i have seen.

You mentioned Bob Pearson, of Pearson Arrow surfboards in Santa Cruz…he’s been shaping and riding twin longboards since the 80’s.  Consider calling his shop for the factory number, and ask whoever answers there (usually several shapers in the bld mowing foam on boards)  for some data points…



Larry Mabile uses twins and twinzers for some of his longboard models.  This one is an 8-6:


Cheers for the words guys , it all helps

but , no numbers ?

I work construction , I’ve got a thing for specs and drawings.

I scaled some measurements off that Infinity photo using the futures boxes as a datum

and allowing for parallax and screen distortion it looks like they’re set at about 13 -14 " so that’s what I’ll run with I think , unless I hear different.


surprised nobody has recommended you attempt contacting Greg Griffin; he has made very nice looking hp longboards with twin fin set ups

just mentioning it

Greg's website:



I forgot all about those:

consider adding a couple more boxes, use FCS Fusions for the sides,  so you have some fore/after adjustment, try it both twin and quad…or even 5 fin ala Griffin…?

I’ll be interested to know how its goes  both the plugs in  my lb are cracked and need replaceing could be  an excuse to move them…

The fins in the  Griffin boards look quite far back 9in maybe? Hard to tell in a photo.

Yeah they’re beauties aren’t they , those Griffins ?

I saved that photo to file years ago - one of the things that made me contemplate playing with the twin fin idea actually.

The placement on them seems about 9 1/2 , using the plugs to scale off - but GG’s famous for his unusual placement re twins and it’s all related to his rockers , bottom shapes and templates of course.

I think it’s just over 13 on the Cluster -  placement for the 2+1 sidebites on my board  will be 17 1/2 , pretty close to McKee’s quad recs. , ( I can fiddle it by altering fin bases) and McKee says 9 7/8 for quad trailers , although I’d want to go more rail oriented  so yeah maybe I’ll put extra boxes in and go nuts !

I usually use probox but might have to mix brands so the boxes don’t interfere with each other.

PLenty of time , I 've got another board to build first.Meanwhile anyone got those figures ?

not a longboard , but a 10’ gun for Mav’s