Not finding any direct commentary on this in the archives, though it seems like an obvious recurring question…
I shaped a 6-7 squashtail thruster for a buddy (6’ 7" x 20.5" x 2.75"), thickness carried out to the rails in case that makes a difference, and I’m just wondering what others’ findings have been as far as best fin cant settings for thruster vs McKee quad layouts on the same board, whether most often the best front fin cant settings for quad turn out to be the same as the best cant settings for tri fin use (again, with the same front fins).
The rears of the fronts are 1.25" off the rail, 1.25" toe, center box rear fin’s back edge is 3.5" off the tail, quad trailers at set at McKee recommended spots.
My best thruster result has been with 8 degree inserts (Probox boxes – I’m sure there’s some compensation happening for the concaves), and with the same front fins I’ve been getting mixed results with 6 degree cant front / 4 degree cant rear and with 8 degree cant front / 4 degree cant rear.
Very curious to know what others’ thoughts and findings have been with 5 box layouts and running Tri vs McKee quad, specifically regarding best cant layouts, how different foils in the rears may or may not affect that, etc…
I’m too old to test ride these boards…so I’m sure I’m wrong here…My old eyes say…
Can’t is not such a big deal…It’s more about where you place the rear fins…close to the front fins so it rides more like a twin…
…or…put the rear fins more towards the back…closer to the stringer so it rides like a thruster…I don’t surf like Kelly…Kelly rode a Quad at pipe. …but not like my Quad set up…
I don’t surf pipe. And I think that fin size is more important than can’t…but like I said…I’m sure I’m wrong here…Have fun…go surfing…Ray.
I could add a note of my own, re the board that brought the question up for me (described in original post): I ended up having to do a bunch of repairs, and for good measure re-hotcoated the bottom after sanding it again. After that, I guess the hull changed a little because now the board rides better as a quad than as a thruster, and 6 degrees seems the right amount for the thruster set-up, though response with 6 seems not quite as good as I was getting with 8 before).
Does any of this plug into others’ knowledge about quad vs tri set-ups in any additional ways, or is there a change in the hull you might expect would produce that different result for fins, assuming what I’m saying is accurate?
If you do the same board as a tri or quad, is there any consistency to differences you’d tend to incorporate in the fronts (I guess rears are also a factor here, as stingray pointed out)?
I won’t name the name because I don’t know if the info’s valid, but a friend told me a well-known local shaper (sort of old school?) says he won’t do more than 4 degrees of cant on any board, which I guess would be for quads and tris both?
I aint no expert here, but ive been mucking around with cant on my 5 fin. My advantage is that im using the 4s system and for the quad ive tested it at 6degree cant which i found very responsive though once the size picked up felt a bit hows ya uncle when ya put the boot in. I changed it to 4 degree cant and Ive found it a lot better.
Im waiting for the size to pick up again and will run the thruster set a 6 degree. But for the quads I like 4 degree.
