fin box drag, options

I checked the archives, but am looking for any more input on how using a fin box may increase drag. I want to be able to use various fin setups on my next board, and am thinking a medium box, side FCS and a single FCS tab for a type of “supercharger” option. This way, I figure I can go from single, to twin, to thruster, to a twinzer type setup, to a five fin with the canards. I realize more fin area increases drag, but am eager to experiment some. I also realize that placement of the box and FCS tabs will greatly change things. Is using this type of setup going to truly give me a great difference in performance, or would I be better off focusing on one type of setup (such as a single box, or FCS thruster, etc.) What are everyone’s thoughts on this? Thanks- ryan

it depends on what type of board you’re making, but i think that sounds like a great setup for experimenting. i wouldn’t get too worried about drag from the box, my guess is after a couple times as just a twin/quad you’ll settle on a center fin set up. rustys new rpf box type fins look cool.

The ability to change your fins is a big plus. I have made boards that were so so in the water. With some fin adjustments they have become some of my favorite boards. I would stay away from using fcs longboard set up (6 plugs in a row) for your center fin setup (if you are going to use like a 8 to 10" tailer). I have tried them on several longboards, and they always seem to break or pull out. I guess a tall fin secured by 4 tabs is just not enough. It might be an interesting option if you were to use a shortboard style trailing fin (G5 etc) with 6 plugs in back. That way you would have a greater range for fin placement for your trailing fin. If you want to try a range of cutaways, boomerangs, etc. Then the box is the way to go. Maybe Tom from red X can give some suggestions?

mike d., Thanks for the consideration. Fibreglas Fin Co. has made some longboard center fins that fit our box. True Aimes has also made us some 6-1/2" Bonzer center fins. I am testing a new McCrystal Bonzer (as soon as I can get to some surf). You can get them through Larry Block. Initially we focused upon the short board market. Most of our templates are for short boards. But, we do have two side bite templates. There are definitely more single fin templates available for the traditional single Fins Unlimited box. But, there is also much more slot to create drag from them. Herb is testing out Red X in his next board and I have put superchargers on one of my test boards. I did not use the FCS plug. I just cut a slot withy a dremil tool and bonded the superchargers in with milled fiber and laminating resin. Herb’s superchargers definitely gave me more gluide. But, I have not really had enough time to completely evaluate their benifit. Goodluck with your experiment. But, just remember drag is not the only draw back you will find by having extra boxes in the board. You will also add weight to the tail and change the flex characteristics.

tom, when you get some more time on the superchargers please post your feedback. any plans on bonzer side(keel) fin templates? my current glasser doesn’t do red x but if you made bonzer sides i’d go across the alley to a place that does…

Hey Tom, how far up is your center fin on the Bonzer and can I get one of those 6 1/2" fins. I have two boards at the glasser and two more that I’m currently shaping and all will have Red-X fins. Stoke! Scott

tom, when you get some more time on the superchargers please post your > feedback. any plans on bonzer side(keel) fin templates? my current glasser > doesn’t do red x but if you made bonzer sides i’d go across the alley to a > place that does… I will definitely post the results when I have had enough surf time on the superchargers to give them a fair evaluation. Our box is a bit on the over kill size for the superchargers. So, I will be spending more time focusing on the bonzer evaluation. Hopefully, tomorrow will be good in La Jolla. San Clemente is pretty well protected from most swell activity this time of year. We are definitely interested in making a set of keels for the bonzer program. But, I need some board time to evaluate and some education on the keel templates, foils and fin angles. The trailing edge of the center fin is 5-1/2" up. Give Larry a call at 805-583-0057 to find out when the next run of Bonzer center fins will be made. I know Casey McCrystal has most of the last run. I got one for my board and one for Dev Gregory to experiment with.

Thanks Tom.