Quad fin size?

hey guys!

ive done a lot of surfing before but only recently new to stand up.
ive done a lot of fin experimentation before on my surfboards but not a lot on the sup aside from single or single + 2x side bites (from my surfboard).

my current board has a 4+1 set up and I'm curious to give quads a try.

Do quads for sups need bigger fins? I've seen some fcs sets that are the exact same size and template as the normal surfing fins but just say 'able to use for sup' while other sets seem to be a bigger template and say that sup quads need to be bigger? My current site bites are smaller than a standard fcs m2 fin but I see some naish boards come standard with fcs m7 fins or all quads being around that template.
What size quads on the front and back should sups take (roughly)?

Coukd i use a standard surfing set that I already have? I'm only 70kg so my current fin sets are all a small or medium size for surfing. Not sure if that translates in to too small for sup?!

It totally depends on the board. I would start with whatever you use on your surf board and work from there. A lot of modern sup shapers have worked really hard to get their tails down close to surfboard sizes so I feel like regular sized fins are working better on sup than they used to.
This interview with Tyler Callaway from FCS is worth a watch if you have the time:

Thanks guys.

i got to try a Jackson close deep surf pro 8'8 x 32 x 135l today with quad fins in it. Was stupidly fast and skatey on a steep drop compared to my normal 2+1 set up with a 8" centre fin.

The board only has a 5 future fin plug option so I can't run a longboard fin.
How does a normal surfing thruster set go on a sup like this compared to quads? I thought the thruster would be way too small, perhaps less stable than a quad due to less overall fin in the water?

it was ok on the super off-shore wind and chop today but would a touch more stability if possible

Thanks for the reply! I was able to get a couple of solid and heavy / steep head high waves today but would just like a bit more stability- especially
while I get used to
tje board.

what would be your suggestion for gaining more lateral stability on this board given I can't put a longboard style fin in? Would a standard size thruster or quad be more stable for paddling and going down the line?
Not sure what size quads are on the board (they are Jc deep 2.0 carbon I think?) and my normal surfing thruster is just a medium size although slightly bigger dims for more drawn out turns.

thanks!

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Loz79 said..
I prefer thruster over quad. Quads seem to keep me flatter on the wave whereas thruster allows for tighter turns on rail..quad a little quicker but more drawn out turns.

I would say because your rear quads are too big.

I don't know why, but on normal SUPs, that is wider and with more volume than prone surfboards, I had great results on using big front fins, and very small rear quads. The big fronts (MR Twins for me) give an insane burst of speed into the turn, and the small rear allows to actually pilot the board in the turn. Too big rears and I had your symptoms.

This is less true with narrower SUP boards, where I found out a similar setup to the prone surfboard works well.

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Tardy said..
colas are you still riding very short boards ..

Yep. Well, actually since I use now wide nosed boards (hybrid noses between a Tomo and a regular nose), I have lengthened my usable rail length, so although still riding a 6'10" in small waves (Gong One), and around 7'4" otherwise (Gong fatal), their rail line give me the stability in turns of longer boards, while keeping the acceleration of short boards.

But this is because I am not attracted to big waves, so I nearly never use my "minigun" 8'4" anymore. I guess this is because after so many decades surfing small waves I am not comfortable with the big conditions (fancy words to say chicken! :-) ), but also that, although you go fast in big waves, I actually feel that your speed relative to the wave is more constrained, limiting your options. Plus the added risks do not seem worth it at my age. So I do not need long boards for taking off in big waves.

Also, I am short, with a narrow stance due to bad hips, so shorter boards are easier to ride shortboard style for me.

On foil profile, yes, this is quite underrated. In the interview on the progression project blog with a FCS guy, he said the pros were liking or not a fin depending mostly on the profile of the leading edge (they liked the sharp front edge of flat-inside fins). Plus the late Alan Byrne boasted to be able to noticeably enhance a board by just spending 10 minutes on its fins with a piece of sandpaper...