I agree with Grasshopper 100%
Also, it’s obvious from watching The WaveGrinder videos that they don’t understand how a competent Surfer uses his fins.
Their videos also show that they don’t really understand how a surfboard turns.
As far as consciousness of the surfer a fun joke to play on your friends (if they ride thruster or quad type boards) is to switch the left and right fins so flat sides are on the rail - easy to do that without them noticing. Or to make it more like wavegrinder put all center fins in their board ha! If they don’t notice something is up while surfing then they are not skilled enough to make any determination on fin design 
Surfing is so subjective. One person’s favorite is never everyone’s favorite. We all surf differently in different locations riding different boards. My brother was an early adopter and used it. He said he liked it, but he doesn’t use it anymore. He gave me a set of the sidebites, but I have never tried them. I guess I should, but I’m happy with the fins I currently use. The places I surf are quite a long paddle from shore, and parking is not nearby, so swapping fins is a chore. If they don’t work, you’ve blown a session.
Maybe I’ll try his single version because I’m mostly riding single fins these days. It should be easy to notice a difference in my daily drivers.
Not sure of the science, but I have used glassed on fins with bulbs on the fins and I’ve always thought those boards were really good. Was it the fin or the board? I know really good older surfers, legends, who use winglet fins and really like them. They also like the curved sidefins.
Hahahahaha
There is a big difference between dragging your fins through the water and pushing off of them
Good point Sharkcountry…
I think you touched on the main thing that a lot of folks (especially the ones who come with tons of “science”) miss in regards to design.
The ultimate “proof” is under your feet. All the theory and science means nothing if it goes against real world proof.
How do they feel under foot? Do they help you surf better or not?
by the way i am a huge fan of CAD and predictive models, but the models have to be relevant and the predictions have to be validated with the results put back into the model through a feedback loop. surfing is so dynamic and varying it is a really tough task to make a predictive physics model for it.
i like what the wave grinder is trying to do - i would try it as a single or rear fin. i mean this guy is having fun with what he knows and tooting his own horn a little - that is cool. but there is no need to put down others work (which has actually been empirically proven) by saying it is based in voodoo - that is off base and in poor form.
Most modern surfboards are made up of two basic components , the board and the removable fins , nothing else is needed to go surf and some really talented folks can do without the fins but for most of us that is not the case , we all know that fins have the single biggest influence on a board and the surfers performance , and that imo is the main reason for removable fins , it allows any single board to be used by different surfers of different skill levels and that same board to be used in a great variety of different conditions all by changing the fins to suit . to dismiss any fins or combination of fins for any reason other than having tried , experienced , experimented is not now the way nor has it ever been the way to advance surfing or surfboard building , surfing history is littered with innovators and progressive thinkers that have moved surfing forward and those folks did not do it by listening to others who dismiss their ideas out of hand , Thrailkills twingle set up is a good example , does it work , yes it does , have you tried it , why not , does it work for everybody , probably not , would it work for you , how will you find out , Thrailkill also uses small fins with no toe in , is he wrong , again using Thrailkill as an example he is a big advocate of thick fins , do they work , yes , are they better , have you tried them , if they do work better than the current norm why are there not lots of thick fins for sale to the thick fin fans , the surf industry if there really is such a thing is slathered in bullshit that is used as a marketing tool , and fins are coated just like everything else , it is the easiest thing in the world to change a set of fins and the fins you try may change everything about your surfing . maybe you need a twingle or a thick fin or just maybe the wavegrinder is your fin .
I make very low cost surfboards. The average cost for the last handful of boards I made was about $100. Just like my boards, I tend to use low cost fins. I’ve been riding the cheapest low cost FCS fins on several of my multi-finned boards and I don’t have any complaints.
On the other hand, I’ve paid up to $120 for a set of handmade fins and I like those in the boards I bought them for.
If I get a really good set of fins would I be a much better surfer, or would surfing be much easier?
I use boxes that allow me a vast assortment of changes, but I rarely move my fins around. I often guess where they should be then go out and ride. In the few times where I’ve had problems with multi-finned boards and tried moving fins, I wasn’t successful at turning a board I didn’t like into one I did. Adding side fins made a huge difference in a couple of boards.
Maybe I should try this one?
I have been playing with the fins in some of my twinzers using 4WFS.
One board in particular, went from barely rideable and no fun to a great board.
Adjust cant and toe made a huge difference.
The absence of any negative ride reports could be due to self-selection:
Maybe only surfers who are inclined to believe the explanations for the design of the Wavegrinder fins will fork out the money and buy one.
From there on they might be prejudiced about how the fin performs, because they would have to admit that they fell stupidly for some hype and got ripped off.
I want to donate one of the Wavegrinder 2 fins to the Swaylocks community for testing. I’m only really interested in single fin testing at the moment, because it is so much more straight forward (literally).
Nominate where you want me to have it posted to first, ride it, report how it goes and then send it on to the next Swayloholic.
Everyone who wants to participate needs to agree to only keep the fin for a short time and then pass it on. Starting in the USA might be the easiest postage cost wise and I think a lot of Swayloholics reside there, and the fins are distributed from there.
That way we might get some less biased ride reports.
Those blefs are exactly tubercles. And that’s the effect they cause. CHeck out webpages about tubercles on wind turbine blades. They also keep the flow attached longer and work at slower speeds so more aoa before stall
I regualrly ride a more traditional railed 9’3" single fin pintail I use an 8.25 inch fin in.
It tops out at 7500 rpm in third. No fourth gear no matter how much juice the wave has.
A standard fin might wobble in my Worn stretched FU box though.
Am in north county san diego
hang20 wrote:“Those blefs are exactly tubercles. And that’s the effect they cause. CHeck out webpages about tubercles on wind turbine blades. They also keep the flow attached longer and work at slower speeds so more aoa before stall”
That was an interesting read, diagonally across so many applications using BLEF technology. Even bicycle rims!
I think related to surfboard fins the tubercles / bumps all sums up as “more forgiving”.
You get extra lift when there is barely enough due to lack of speed/wave size, you loose a little when everything is optimal (and then there is plenty to spare anyway) and you get a more spread-out stall, instead of a sudden uncontrollable event. I think the McCoy Gullwing fin already ‘spreads stall’ over a wide range and will most likely get even better with BLEF.
But it needs objective testing, for which fins are required…skedaddles off to fine-tune OpenScad files full of Roy-inspired finFoil files…
That is an excellent idea Mr Mik , I will gladly participate as I have both the single fin and the stiff quads ( cos I dont believe in flexy fins but that is another story ) . Huck expressed an interest in trying the quads , he seems to be an open minded kind of guy as far as surfboards are concerned and he would most likely post a report . I am in Ventura County and I know Huck some times works out this way , if Huck reads this and pm,s me we can arrange a pick up , and after his test he can pass them on to the next swaylocker prepared to write a test report , if anyone wants to try the single fin who will write a test report and is prepared to pick it up , pm me . Please note I am not trying to promote wavegrinder fins and as I stated in an earlier post I have not actually used the quads this is just an experiment to try something that is new to you that may or may not be better , someone said , a mind is like a parachute it only works when it is open
What base are the quads?
I’ll give it a go.
I’m in pismo.
The quads are fcs compatible , the base of the large fin is 3.1/4 x 5.3/4 tall the small fin is 2.7/8 x 4.3/4 tall .
gbzausa, thanks for the offer to share your fins!
Is the single fin you have the “Original Wavegrinder” of the Wavegrinder 2?
Sorry MrMik but I dont know the difference between model 1 and 2
“Sorry MrMik but I dont know the difference between model 1 and 2”
The original wavegrinder is no longer available for sale.
WG2 is the one you can still buy.
I think the winglets were larger on the first model.