Quad fins - Should I use m3 rear fins with flat or foil?

Just wondering about the performance of the m3 fin in the rear for quads compared to gx? Ive for m7 in the front. Got a 6’0 5 fin set up pod surfboard, wondering if these could work?



“Ive got the m7 in te front”



sure, give it a try, should get a bit more drive with a tad less looseness.  You might want to downsize the front fins by a notch (M5 size) either at the same time, or after you surf it a bit. 

PS I find flat fins in front of quad set and foiled in rear preferable, but your mileage may vary!

Hey there

The CI Pod surfboard?

You a heavy guy?

The gx feels to me more fluid/stable, the flat foiled feels more reactive

but the M3 is bigger, so should be less whippy than the smaller GX


In my experience flat vs foiled for quad rears is often about fin cant.  Foiled seem to be more forgiving in terms of their cant.  If the cant is off for the flat, you may find them very tracky and pretty horrible, whereas if they were just at a different cant you might really like them.

It depends on how close the fins are to the rail.  For me, if fins are on the rail I like nearly equal sized fronts and rears (but be careful of going too big, no front and rear M7s or anything crazy like that).  If the fins are heading into McKee territory I like the trailers to be smaller


quad fins - the endless quest and debate on what works best, subjective to so many variables.

Why every ‘quadster’ has a box of fins used in the quest for ‘best ride’

some truths at least half the time…lol

rear fins closer to the rail, flat or 80/20 is usually the call.

fins closer to the stringer, double foil or 80/20 mo betta

size of fin = width of tail, fin placement and grouping set-up

Like to ride my favorite thruster (Simon Anderson L, Mick Fanning L, old style Occy) fronts and G1000 rears.  My boards are designed with the rear fins splitting the difference between stringer to rail (Rusty formula) so ride double foil for more hold, 80/20 for more release.

Yea, you’ll end up with a box of fins…


Adjustable boxes help too…

Thanks for comments. have been using the m7 in front and gx in back and seems ok. I put the knubster in there for one surf and really tightened it up on some for hollower waves. I liked the feel, free but a bit more control on parts of the wave.


Just also wondering if anyone could tell me if a round tail and a diamond tail will make a big difference in the ride of a quad? 


Ive got a 6’ round and 6’ diamond tail. I cant seem to master the diamond tail quad, way too loose, better as a thruster. Could be lack of skill kookness on my behalf, but the round tail seems good as a quad and thruster. The boards are very similar outlines too.

Anyone experienced this?



sounds more like rocker and/or bottom contours than tail outline

May be fin positioning - fin groups more or less the same?  Or possibly your surfing style - are you more front footed?  RP’s provide a longer sweet spot, allow you to surf a bit further up, load up the front foot more.  DT’s, which I really like on quads as wider tails work well, do tend to require a bit more back foot.

Personally found the nubster to work well in less critical waves allowing more turning off the top and bottom, provide more leverage and shorten the arc a bit.  They do provide a bit more ‘centering’ feel to the quads like a thruster feels, which may be why you like them in hollow waves.

As well as quads can work, fickle as hell to dial in, which is why a lot of surfers play with them for a while, then say screw it and go back to thrusters, which they don’t have to think about.