what's the proper fin placement (thruster) for a six foot double-winged swallow tail fish?? and how do you measure from a swallow tail?
>>> what's the proper fin placement (thruster) for a six foot double-winged > swallow tail fish?? and how do you measure from a swallow tail? I used to wonder about this all the time... what makes it particularly confusing is the placement of the wings... should the fins be ahead of or behind the wings etc.? Now you have added to the complexity by putting fins on a double-wing. This is how I do it, and I've talked to quite a few shapers about this, all of whom seem to mumble vaguaries that neither I, nor they, seem to understand. Consequently, I try to keep it simple for myself... first by never putting in super deep "stinger" type wings... and if so, far from where the fins should be placed. But here's what I do regardless of where the wings are: Place the back fin from 2 3/4 to 3 1/4 from tail. On a swallow, take a ruler and place against back of swallow tail and make this measurement from your ruler (acting as the real "end" of your tail). The side fins should be between 10 1/2 and 11 1/2 inches from tail... also measured from the ruler placed against bottom of swallow. Place the side fins about 1 1/4 inches in FROM THE RAIL... and then just toe in from 1/8 to 1/4 inch, don't worry about wings in front of the back of the fin. Basically, I used alot of words to say, place the fins exactly as you would any 6' thruster. You might want to put the side fins 1/2 back from the "standard" thruster... this is to more suitably accomodate some big twin fins if you choose to use them instead (I'm assuming here you're using fcs). Anyway, I say shape a few boards varying the fin placement and noting differences in performance. I realize that can be a luxury for the beginner, so alternatively, sneak into some surfshops with a ruler and a t-square and check fin placement. If they get annoyed with you, who cares? If the shop guys are cool, they won't mind, as long as you don't bang up their boards. It ain't classified information. There is no standard that everyone follows. Check out the shaping thing by Dave Parmenter on Swell.com, he says something about fin placement, too. I also welcome any shaper who has a different, or more definitive, take on this issue. Craig http://www.albersbrothers.com http://www.albersbrothers.com