Quad Fin Placement

Currently working up a Quad Fin template.  6'11" x 21" T-15" N-15 1/2" wide point 3" fwd of center. Round tail with a wing 1/2" behind front fins. Any opinions on fin placement from tail? Mahalos UNDERGROUND. 

Check out:

http://www.mckeesurf.com/brucemckee/multisystem.htm

His placement formula worked for me.

Dave

I didn’t like my mckee setup boards…I use Larry’s quad setup…they are more rail oriented and are positioned so the two fins work in concert with one another.

http://www2.swaylocks.com/forums/how-i-probox

I would love to see some updated opinions on this topic.

I have done both McKee and rail-oriented fin placement in my last few boards. All between 5’11 and 6’3". Did the McKee on the 6’3", which was a relatively narrow round tail (14.5" width) designed for steep/hollow waves. Board worked great frontside (good drive and predictable) but seemed a little out-of-synch going rail-to-rail backside. Played around with fin placement but mostly used the PC5 Quad finset.

Did the rail-placement (12" and 7" with trailing edge of both 1 1/4" from rail) on my shorter, smaller, wider tail boards. These boards are plenty loose, but lack drive and feel almost twin-finish. They tend to slide out unpredictably sometimes in pocket turns. Had the best luck with bigger fins (Hynson Quad).

Both setups have toe-in of 1/4" for the front fins and 3/16" for the back fins.

Looking around, I see that the big guys (Rusty, Lost) seem to do something in-between. Front fins at 11-11.5" and rear fins at 5.5 (half the distance). Rear fins also seem to be set further away from the rail (2"?) but not McKee far.

I would love to find a nice compromise between the two extremes. Want the drive of the Mckee but better synch going rail-to-rail backside.

Anyone have any good fin placement numbers/formulas that they love for a well-rounded quad shortboard?

Sorry to be lazy at the moment - but I have posted some info about my quads base on Robin “Handshaper” Mair’s set up.  I tried McKee and liked it, but it didn’t seem to have the speed some talk about w/edge finned quads.  

The main deal for me is using an adjustable fin box system (I’m using RedX) to find the sweet spacing - for me @ 7/8 on my toe side, trying to keep the set as far forward as possible, and @ 1 1/4 - 3/8 on the heel side, and a little bit back.  

The front fins are basically in the same position as a tri fin.  All fins @ 1 1/4" from rail.

In the end, for me, tri or quad, I’ve found I like the heel side fin further back, and the toe side forward.  I will off set my boxes even further on my next board.

As Robin, and others, have mentioned, with the edge fin set up, it’s all about the interaction of the two fins…  I found once I made the spread over 1 1/2" it felt like a tri… some fin drag, but not as bad as a center fin.

I would be putting them 11 an half front and 6 rear. 1 and a eighth in. I was using Mckees but finding it very stiff. Then I met a glasser who worked for a high performance shaper and he said the closer the stringer you go, the stiffer it gets. I tried pushing the fins up and lost a lot of drive and consequently ended up on huge fins. I use a toe in that shoots 2 and a half to 3 in wide of the nose and aim the rear ones to the same point. 6ft boards 11 at front and grom boards I pull em all back another half inch or so. I dropped the fin sizes with this config and they~re going very nice.

Pretty rad what taylorO is doing, like it. My summation is that McKees turned out the way it did because it was developed in Hawaii where the waves are definitely hollow. But for east coast Aus, it just doesn~t work for me. Having said that, Kellys set up looks very Mckee and he won mushy Snapper barreling chopes and mushy Trestles!