A little fin advice sought.

I recently picked up a custom board from a widely known shaper, but who generally makes thrusters.  It’s a 6’4" epoxy round pin that I requested have a quad setup.  So the board was made with a McKee arrangement, with the trailers closer to the center line than the rails and the thing is a squirrel.  Seems to paddle faster that the thruster version I had, but not much drive and very squirrely and odd feeling when it’s on a wave.  I have a set of Futures MB2 quads on it (http://futuresfins.com/en-us/mb2-honeycomb-carbon-blue-1262-458-00-detail) and wondering if something like a Controller set might work.  I have a set of those on a wide tailed 6-0 grovellor and they’re great on that, just don’t know what to do.  I’ve read the threads here on McKee fin arrangements, looked at his site, and read about pros and cons, but this thing is just wobbly-feeling on a wave.  Perhaps more time on it, maybe different fins.  If anyone is familiar with that setup and can offer advice on fins, please help.  Much thanks in advance.

Flat foiled rears are better on quads when the rear fins are set closer to the rail.  With the Mckee placement, double foiled trailers work much better.

Had the same problem with my first quad until I swapped to double foil, was like taking the emergency brake off.  Board settled down and flew.

And easy to over fin the trailers - suggest starting 4" or so, the quad trailers work more together with the Mckee set-up, easy to overfin the rears.

Try some double foiled fins, give a report…

 

  

The trailers in place are foiled 80/20, but I do have a set with symmetical foils on the trailers.  I’ll give those a try.  Board seemed less weird today, but then, the surf got really weird with a continuous boat wake type interference pattern on the waves.

I’m riding double foiled rears on my boards that have the McKee quad layout. If you can, move the fins as far apart (for and aft) as possible. I use proboxes, so I can get some fore and aft movement. That should add some drive to the turns too.

The boxes are Futures, so no adjustment on these.  I had to order a pair of symmetric trailers as I didn’t have any for these boxes.  I was considering using two thruster trailers and would then have four fins exactly the same size, but thought that might be too much with the trailers close together.  Thanks for the advice.

find me a guy who rides quads, I’ll show you a guy with a box of fins… hard to dial them in at first

but when you can find the sweet spot mix, you also find another gear…

 

Put a set of symmetric foiled trailers in and that cured the squirrely feeling.  Must have been some odd cavitation or eddy effect from the two fins closer together, but not present with these new fins.