It was perfect (cutbacks like “buttah”) in every way but one. When I set up to drive down the line, I got big directional changes but no drive. On one wave, I could see 25 yards of perfect face in front of me, and I just wound up turning up and down the face until it ran out, instead of powering through the end with a buttload of speed and throwing buckets (or trying to, at least).
Anyway, I think I know the problem, so I’m looking for verification and
solution. I’m running the injection-molded FT1 set, the big twins
plus trailer, and I think its just too much fin area to have in a
plastic fin. I think I’m flexing the tips too much on my pushes,
causing the loss of drive and big directional changes. Do you
suppose simply switching up to the fiberglass version of this same
template would take care of my problem here, 'cause I really
like driving down the line. Or should I bump up to the glass
keels and get the stiffness and extra area for driving off of?
Lot’s of flat surface on the big rail fins makes for reduced trim speed and poor down line surfing. I don’t know what the board looks like but it sounds to me like it’ll turn great and surf top to bottom very nicely but fails to project much speed and thus doesn’t use the wave face effectivey enough to keep up with faster sectioning waves.
I won’t venture to tell what fin set-up will work best for the board without know lots more about it.
Sometimes boards just work better with smaller rail fins and bigger center fins. The C5 fins can be minimized to maintain the channeling effect they give and still help to quiet the water for the main rail fins. This may be you’r solution. It’s worth a try at any rate.
try two smaller side fins , with a larger back [fibreglass] fin. Keep the two little front side fins there too if you want . Experiment ! and have fun !!
…I thought you were on your honeymoon Jarrod ???
…what did you take a laptop with you or something ?? [er…computer , I mean]
That makes a lot of sense, Rich… But I must ask, if big flat side fins hinder down the line speed, then why is my keel-finned fish so fast? Probably the paralell rails in conjunction with the keels, right?
If it helps at all, rich, here is the full outline shot:
And Chipper, I leave on the 25th for the wedding/honeymoon. Just trying to get the board dialed before then!
A quick read of your problem + a quick glance at your trailing fin = get a bigger trailer with more base. It’ll stiffen your cutbacks a bit but give you more drive. With the adjustable center box you should be able to dial it in for a reasonable compromise between the two. Try it with and without the canards? Nice balsa comp/sand by the way.
plastic fins lose drive…u know when you see someone…hauling ascc down the line and then go for the big cutty and fall straight on their back…PLASTIC FINS…or to much flex…also a bigger back fin will give you more down the line drive…get halycon to make your fins he is the expert…in construction and design…
I’d like you to try THAT ! [With a good-sized FIBREGLASS fin]
cheers !
ben
have a great wedding , honeymoon , and marriage , and surfs , mate ! [gee , I actually wrote it in that order ?? Must be “softening” , as I near 45 ! [three weeks time]
Aloha, Looks like your fin placement is best set for a traditional thruster set up! same size trailer fin! the medium used in building this board may also go best as a single fin ( 8.5" or 9" fin good base and pulled tip) . The C5s may not work on this shape!! try a thruster with equal size fins or just a little taller for the trailer ( remember Simon Andersons thrusters ? third fin was just a bit larger, I also noticed your fin placement looks to be set close to the tail? this setting is best for the above mentioned, or go single like Chyane suggested …
Aloha, Have a great surf ! Clyde Rodgers Edge Fins
…and , much as I DISLIKE polycarbonate fins , I must say that the winged keel went well on my similarly shaped 6’5 “benzer bottom” abomination I made** . Matter of fact , it seemed to be the only fin out of all the different configursations I tried on that board, which actually held the big wide thick floaty tail in , strange though that may seem .
Jarrod , do you have , or know anyone who has, a winged keel ? [I think you guys probably call them “star fins” there, yes ?]
Schwuz, don’t get too caught up in the fin shape, foil type, or concave/no concave.
Toe-in, cant, and fin area are the major players here. You had them out of whack for achieving thrust. It is easily remedied. Use a rear fin roughly the same area, same shape, as the rail fins, toe-in the rail fins 1/4", and cant them 4-6 degrees, and you get thrust.
Now, fine tuning the rail and rear fin shapes, using twist fins, concaves, etc, can optimize thrust. But these are smaller impacts than using fins of the same area and shape, and getting the toe-in right.
Ok, well toe-in is already 1/4, and cant is built into my fins… I must have had fin area out of whack.
Maybe I need to clarify my experience…
I have NEVER (never) ridden a thruster setup I have enjoyed, or have been able to “drive”. My drive-est boards ever have been my classic fish, my bonzer egg and bonzer stubbie. I found that they created speed very naturally (for me), but still rode well in trim, while a thruster needed to be “worked” constantly to keep moving. That’s probably why I didn’t go straight to a tri- setup as my default on this board, right from the start. Also probably why I seem to be going at this a bit backwards. The consensus, however, seems to be that I need to try a “normal” thruster config on this board, and that should clear up my drive issues. I am certainly not too proud to give that a try.
I have always been a big fan of “alternative” fin configs, as evidenced by my above list of favorite boards… Because of that, in this case I might be a victim of the medical profession’s “if you hear hoofbeats, look for a horse… Not a zebra” scenario.
However, I am still totally open to any other suggestions that aren’t “make it a thruster”, so keep 'em coming.
Also, if it makes a difference in the assessment, I drive off my front foot and my rail, not off my back foot/tail.
You will get at least a thousand different solutions to creating good fin perfromance if you talk to enough people.
What are the demensions of the board?
Nose Rocker?
Tail Rocker?
Rail and bottom configuration?
Here’s is what I sense will work.
First off it doesn’t look like it’ll work too well with a fishy type fin set-up to me, just to much curve in the outline mate.
The rounded outline of the board tells me it will surf very nicely with very small canards in the C 5 boxes, rail fins around 4.5" full based or 5.125" Mentals, and either a full based trailer around 4.75" or a 5.625" Mental depending on the how you want the board to feel. It definitely wants a center fin and possible one that is slightly dominant in more demanding surf. You can get a fishier feel from the board by Moving a cutaway center like the Mental a little forward to close up the cluster. The cutaway template will let the board transition from rail to rail nicely and still give the board the drive it needs.
A set-up like the one in the attachment with a center of about 5.625" and little C5 canards or a small full based template will work well when the conditions dictate lots of trim speed. Changing to a full based center of about 5.5" in bigger waves and tuning the board to the conditions by moving the either center fin fore and aft and – or removing the canards will give you lots versatility.
Yep! too much flex is a killer! i know this one first hand from this
and a flexy rubbery fin on my stubbie.
I’m thinking i might favour wood fins (yet to try them) as I like harder plastic fins and love fibreglass fins but they can be a tad heavy for smaller boards.
