Silk Launch Interview

Silk Launch Interview

Author's Note: It is with immense sadness that after the publication of the below Chipri physically left us however his spirit, passion and joy remains with all of us. Ride4chipri.

We’re excited for the launch of the new AFS Silk line of Foils, Stabilizers and Masts. With this launch AFS recently recorded and posted the below interview with the key players of this new product. It’s a great resource but it’s only in French so we translated it and transcribed the first sixty minutes below, it has been slightly edited for brevity. 

Youtube Video

Introductions and Bios
• Laurent Borgna - Designer AFS - joining the interview from New Caledonia, is a professor by trade although less and less so. Passionate boardsports athlete for over 40 years. Lead designer of the Silk lineup.

• Chipri Courde - AFS Rider - has been surf foiling for almost 4 years, has been the lead test rider for the Silk lineup.

• Richard Boudia - International Business Developer - has been with AFS for a year. Has been an avid boardsports practicioner for over 20 years, has taken to all foil disciplines but a preference for downwinding.

• Emeric Mouret - 3D Modeling Engineer - has been at AFS for 3 years and is involved with launch and prototyping. Has a background in slalom windsurfing but converted to wing foil racing which is now his primary activity.

• Quentin Riou - Materials Engineer - Has been with AFS for 5 years he is focused on the materials and evolution of those across product lines. He is an avid wing foiler.


Antonin from AFS: Surf foiling is growing rapidly in popularity, but why focus so much on this category with the Silk and what were the goals for this product line?

Richard: We noticed that there are a lot of good surf foilers who would enjoy a higher caliber of product. There wasn’t a foil that was maneuverable across a wide range of speeds, and could glide/pump well, it’s very difficult to have a foil that maneuvers really well and pumps/glides easily. Along with those two components maintaining the sensation of flow was a top priority. With the Silk lineup we feel like we’ve hit all of these goals to have a fantastic wave riding machine. I say wave riding as this encapsulates many aspects of foiling that the Silk is ideal for prone/surf foiling, SUP foiling, wake foiling, downwinding and of course wing foiling. The Silk has maneuverability, speed and an unrivaled smoothness that makes it a great freeride foil. Is it a race foil? No, it was not designed for this.

Antonin: Laurent and Chipri you’re quite the dynamic duo and are regularly together, how did you meet, how do you work together?

Laurent: The truth or romanticization? We were initially supposed to meet a few years back with Richard as well actually, on the Atlantic Coast of France near Bordeaux for a photo shoot but Chipri injured his knee and we had to cancel so we didn’t meet up. A year later we met on Moorea and Chirpri came back to New Caledonia where he was supposed to stay with me a week but that turned into a month and a half. We rode a lot, worked a lot, made prototypes of wings, fuselages, everything. We became lifelong friends.

When we did all of the prototyping on Noumea it was great as we were able to foil the same spot day after day, this was important during testing as conditions affect the wing so if you are constantly changing spots it’s hard to iterate on a design. Even at the same spot the varying conditions can affect the feelings and prototyping. Once we felt like we had a great prototype we could go test further in world class waves either in New Caledonia or on Moorea.

Chipri: When we are not together he ships me prototypes to Moorea, I go out and ride them, then call him the moment I’m back ashore to give him fresh feedback. He really likes it when I call him with immediate feedback. We talk regularly but I also take notes and am very focused on feedback when prototyping.

Antonin: You were discussing how you work, why did you join AFS and how has the integration been?

Laurent: The brand I was working for didn’t have a good R&D budget, I had been approached by AFS so I listened to what they had to offer and decided it would be a good fit.

Emeric: The time change has been the toughest. Our calls are at the beginning of my day at 6 am and the end of the day for Laurent so he has a brain full of ideas and I am just barely waking up ha.

Quentin: We heard Laurent may or may not join us, and then one Monday it was announced and next thing you know I’m working on four prototypes at once.

Emeric: Here at AFS we have people with different roles and specialties and when they announced Laurent they told us don’t worry this guy is a Swiss knife he can do it all and sure enough he does all of our jobs just as well if not better haha. It was awesome we were able to compare and contrast processes, notes, ideas working together we had no secrets and we built on top of each others experience to make each other better.

Antonin: Great! Richard can you introduce the Silk lineup and how it differs with our Pure lineup?

Richard: The first sizes we are launching for the Silk are the 650, 850 and 1050. The Silk 650 is a high performance surf foil, also suitable for wing foiling in wing speeds of 18 knots plus for someone of average size. It pumps reasonably well but better suited for an experienced pumper. The Silk 850 will be more forgiving for pumping, with this size you get a wider range of use, uses and users. The Silk 850 is good for surf/prone foiling, wing foiling, wake foiling as well as downwinding. I never have just one foil but if I had to have only one foil the Silk 850 would be it. Next is the Silk 1050 which is well adapted for small surf conditions or just not powerful surf, it’s a great pumping foil. Which also makes it a fantastic downwind foil, a great light wind foil for winging as well. Across the Silk lineup they are distinguished by the smooth maneuvarability.

Antonin: Speaking of smoothness Laurent and Chipri could you talk about what gives the Silk foil it’s smoothness?

Laurent: Either you make a foil very simple with basic staright angles and a rider could develop the ability to ride over and through the rail to rail instability. But if your doing big flowy turns you need a foil that can smoothly go rail to rail. Every component of the Silk contributes to it’s smoothness. The thickness of the profile on the ends can create instability, so you need thinner profiles on the wing ends, the curve from center to end affects the smoothness of transitions. The smoothness comes from every parameter not just the humps, the humps have been centered as they create a channel which creates drive and the humps in the center are slightly larger than the outer ones. Of course rigidity comes into play, the more rigid the more responsive the control is.

Antonin: And Chipri can you talk about it from the riding standpoint?

Chipri: It’s very different with and without the humps, first it gives you a broader speed range by staying on foil at lower speeds, you can foil slower without stalling. It also lowers the speed at which you take off on foil, it has a lot of drive through the big turns, and the water over the foil is really smooth there’s no cavitation and nervous energy.

Antonin: What’s the difference between the Silk and Pure line, how are they different, do they have different programs?

Richard: The Pure foils ride really well being flat so it rides really well for wing foiling. There’s a flat spot when a foil goes rail to rail that really good riders are able to ride through smoothly but with the Silk, it’s the smoothest turns. Given identical conditions some people just like a different feeling from the foil. The Pure is a great high speed foil that needs a little more speed to foil, the Silk is going to be able to take off at a lower speed. They are just different feeling high performance foil so the choice between the two is a personal preference. At the end of the day all of the foil profiles exist due to preference, you have the hump foils, the medium aspect and the high aspect none of which are worse than the other just a different feel.

Chipri: I find that the dihedral curve of the foil makes it feel like you have a lot of support/push even when leaning aggressively into a turn. That lift feels constant and consistent throughout the turn, it keeps its speed with a lot of stability. It’s a foil that works at all angles

Laurent: I don’t hesitate when discussing hump foils as it’s so natural to me, there’s been a lot of research written about the effect of the humps. It smooths down the stall it’s not revolutionary, you don’t go faster with the humps if you did everyone would be talking about it, the America’s Cup boats would have bumps. So the stall is minimized and smoothed out but the flow is very different, it’s very smooth like surfing through smooth oil. The humps in the tail really help with the control. To me this is all so standard, I just know the humps are best so I have them on all my foils.

Antonin: The next subject I want to touch on is the materials and the mounting of the mast to the fuselage, there were a lot of conversations around the mast mount.

Quentin: For the Silk foil we stuck to the same materials as the Pure line up as it’s already part of our AFS Advanced line of high performance products. UHM for the mast as it needs to be a thin stiff mast to interact well with the foil. If the mast is thin you need the UHM to keep the rigidity. However we found that you need some flex and torsion give on the masts for the foil to perform best. We spent a lot of time optimizing this flex. In the foil construction for the Pure it’s a very thin profile so the foil is whole, the Silk is thicker, so we did a sandwich construction to keep the foil light. It was challenging to make such a light foil.

Emeric: We got to a point where we have such stiff masts that we needed to find some flex in the foil, and this worked particularly well with Silk foil. These are the daily debates in our department. We talk to all the riders across the diverse foiling disciplines and take in all of their feedback to try to optimize all of the foils. Someone was asking what foil size for a certain weight but it’s not just about foil size you should take into account mast stiffness, a heavier person will want a stiffer mast to make the mast and foil flex the same as a smaller person.

Richard: This is why stiffer is not necessarily better. We were talking about the thickness of the profile particularly towards the tips. By carefully picking the construction we can control the flex, this is where Quentin and Emeric’s expertise is crucial as they can accurately build and replicate the flex pattern. These are the critical spices for the recipe, to savor all the flavors of a great foil there has to be the right mix of flex and stiffness. If we project into the future it’s evident that the flex parameters in the right places are going to gain importance, this is the case in surfing and windsurfing already where people spend ungodly sums on fins that are built to the highest degree of precision. The expertise that we have in our factory to be precise and control these factors, we’ll continue to iterate particularly with this team, there’s no way we won’t be able to satisfy the consumers demand for precision. We already see it in the UHM masts the slightest changes make a noticeable difference, we spent a lot of time testing.

Quentin: We get feedback so quick, I get the prototype out in the morning by evening I have feedback and the next day I have to start over.

Richard: It’s one of our strengths: reactivity, we prototype a lot, Laurent is prototyping, a lot of different riders are testing so we test them across a wide range conditions and uses making sure that they work how we want them to.

Antonin: Are the silk and the Kujira 2 identical?

Richard: It’s a radically different construction we do a full carbon monoblock, the aspect ratios are also different. Hump foils can look alike but be completely different. We were able to fine tune the parameters with a precision that our competitors can’t achieve. Our know how is currently on full display on the UHM mast which is also full carbon monoblock construction.

Laurent: On the outside they look a lot alike, I spent a lot of time on the Kujira 2 and learned a lot working on that, it needed to be approachable high performance. When I started on the Silk we went in a more wave riding focus but I used a lot of my knowledge so they look alike on the outside. But yesterday I rode a Kujira 2 and it behaves nothing like the Silk, it’s hard to fathom how the tiniest detail in each of the parameters can have outsize effect on the control, speed, glide and smooth behavior. So yes they look alike but they are totally different. Yesterday for example we were testing the height of the stabilizer and with just 8 millimeters of difference the foil became faster and smoother enabling me to feel more confident. This speaks to just how much the tiniest detail affects the ride.

Emeric: This is also the case with high aspect and mid aspect foils, lots of foils look alike but are nothing alike. I’ve never felt two foils from separate companies ride the exact same.

Richard: High aspect foils for example all of them look the same nowadays, but they have different profiles, outlines and distance on the fuselage from the mast. I think because there are fewer hump foils people quickly assume they are identical but they are not alike.

Laurent: I put as much time into both the Kujira 2 and the Silk but I had a different goal with different knowledge.

Antonin: Which Silk size is equivalent to the Kujira 980?

Richard: Silk 850

Laurent: We went back and forth on this for a while but yes Silk 850.

Richard: With the evolution of the aspect ratios that keep increasing we are able to make foils that are more efficient so the foils can get smaller while keeping the advantages of the larger foil. With the efficiencies gained from all of the parameters including the construction the useable range has expanded a lot. The construction alone gives it a broader ideal range of use, there are gains on the low end and on the high end. This is also valid on the Pure range of foils.

Antonin: With the aspect ratio of 8 which is higher than many foils, is the Silk more oriented surf foil than wing foil?

Richard: I have trouble separating the two types of foiling, it really comes down to rider preferences and how someone foils. Riding conditions will also have an effect on what someone prefers. What can’t be overlooked is the progress made in foil design means that current foils have less likelihood for cavitation and other hydrodynamic issues than they used to, all of our newest foils are significantly more maneuverable than ever. Not so long ago a foil with a span of 90 cm would have been unrideable, now there are foils that have a span of 1 meter that are more than rideable and actually pleasantly maneuverable. That’s because of all the improvements we’ve made not just in foil shape but fuselages, tails and masts as well. Not to forget the construction and how all the components are mounted together.

Antonin: Comments from anyone else?

Quentin: Oh yeah the Silk is definitely more surf style! I kid, I just wanted to get a rise out of Richard.

Emeric: At the time that the Kujira V1 was designed we were looking for smoothness out of the foil but now with the progress made in mast design we’ve been able to increase the span of wings dramatically while keeping maneuverability. For example the Pure 1100 has a span of 1.1 meters but is still very maneuverable and that increased span is ideal for SUP foil and downwinding which are the disciplines that the Pure 1100 was designed for. The Silk on the other hand can have a higher aspect ratio for the tighter turns and lower speeds associated with winging and surfing. These high aspect ratios may even become considered moderate in the future as we continue to make improvements on other components.

Antonin: Question for Chipri, which size foil would you recommend for a light weight surfer under 60 kg (132 lbs) between the Silk 650 or 850?

Chipri: The 650 will be best for them without a doubt, I ride the 650 most as long as the waves are over 80 cm.

Richard: The 650 doesn’t need 2 meter waves, it’s been working well even in 50 cm waves, obviously skill level will matter a lot as well. But to circle back on the aspect ratios which does help with pumping, since we were able to find solutions to increase the maneuverability we were able to increase the aspect ratio so the foil got more maneuverable and easier to pump making it a better foil than last year’s.

Antonin: Great, one more sizing question before we get to the mast/fuselage joint. Which size for someone who weighs 88 kg (195 lbs) who wings in small to medium waves below 2.5 meters?

Richard: It depends on the wind and the size of the sail/wing. Generally foil size isn’t dependent on weight, maybe on the low end when the wind is light and you’re looking to optimize getting on foil then a larger foil is better. But the foil size is dependent on the speed of the activity, the bigger the wave the smaller the foil regardless of the weight.

Laurent: I totally agree I test with Frank regularly who weighs 20 kg more than I and we always ride the same size foil whether we are surfing, winging or downwinding. Specifically when winging though there are very different types of wing practitioners, those who love speed, going upwind, surfing the swell and freestyle so there are wingfoilers who like all types of foils. This explains why in wing foiling we see all types of foils.

Antonin: Let’s discuss the mast to fuselage connection, the materials, the thickness and shape.

Emeric: Laurent and I had a lot of back and forth on this but I had already been deep in thought on this as we just launched the Pure Race Foil 560 with it’s specific mast. We wanted to make foils without compromise, this is the essence of the AFS Advanced line of product. For the race foil we wanted the thinnest fuselage with a tight rigid connection so we used this base of knowledge for the Silk as well. This is a new version as we wanted to make some upgrades, this new connection allows for an even thinner fuselage while keeping a rigid structure. A thinner fuselage means less friction in all directions. The mast is thicker at the connection then thins out to 13.8mm then it progressively thickens to 14.5mm about 2/3 of the way up the mast which also increases in rigidity as you go up the mast. The upper part is thicker but absolutely solid, where Quentin layered in some Pitch fibers into the UHM.

Antonin: Real quick what is Pitch for thos who aren’t aware?

Quentin: It’s a carbon fiber that’s even stiffer than the UHM, it’s just an exotic name for this specific UHM fiber.

Emeric: It comes from the filament of carbon itself. In regards to the shape of the mast and its length I think Laurent is probably better to explain.

Laurent: I get asked why not two mast sizes, we’ve always ridden 75 cm masts and enjoyed that so it’s a bit of a personal choice. We increased it to 82 cm but not too long to keep the reactivity and sensitivity. Over time I’m sure there will be a longer mast, given the skill set and capabilities of AFS they will be able to manufacture them if there is enough demand. However I didn’t want to lose precision, a longer mast dulls all of the feelings, less reactivity and I didn’t want to risk losing the feelings we developed. So I was comfortable increasing from 75 cm to 82 cm but not more.

Richard: We’ve been talking about masts but we haven’t even talked about how to measure the mast. Some include the part within the fuselage, for example we consider this an 80 cm mast but Laurent you call it 82 cm, and with a thinner profile foil like the Silk the foil can be much closer to the surface of the water so even with a shorter mast you have a wider range of riding height. This mast foil set up has that wider range of riding height than your typical 80 cm mast.

Antonin: We have a question about jumping, is it possible to jump with the Silk Foil?

Quentin: They aren’t specifically designed for jumping but you can jump with it. I’m not sure if everyone here recognizes the name Alan Fedit but I have a love hate relationship with him. What I like about him is that if I give him gear and it lasts more than two sessions then I know it’s strong, it’ll last a lifetime for anyone else ha. He’s a great strength tester, the Silk has held up to his testing so far but it’s probably not the best freestyle foil.

Antonin: Laurent I think you wanted to circle back to the mast fuselage mount and while we’re there talk about the M6 vs M8 screws.

Laurent: The mounting joint has had a lot of pressure on it and has been a focus for all brands as the sports and their demands on this specific part have increased. We’ve driven ourselves crazy trying to develop the best mount while keeping compatibility with the existing system but ultimately we found it impossible. Emeric already explained some of the reasons why. But it was still complicated to develop a mount that would work across foiling disciplines with various fuselages and loads. This mount ended up having a 3D link to make it work. However the results are fantastic and I’m impressed with what we built. We found that the M8s are great, and two M8s is more efficient than 3 M6s what was tricky was the inserts being wider and how that would affect the thinness we wanted to achieve but Emeric found a way and we have tested the link endlessly and it’s working. Alan Fedit was content just doing back loops because historically he always broke the screws when doing front loops so one of our goals was fixing that and we accomplished that.

Antonin: Just a couple more questions, Chipri people would like to see you wing foil!

Chipri: I don’t like the wind haha.

Antonin: Richard we were talking about the mast fuselage joint, and people want to know will this mounting system be used throughout the lineup?

Richard: Of course we are discussing it, we are researching the possibilities of where it makes sense. We have a lot of experience and confidence in the capabilities of the Performer mount and we don’t want to go backwards. So we’ll have two standards but two standards with different uses and we will do our best to minimize the number of standards. We just want to know that our clients will be happy and enjoy a well built dependable product, it’s one of the advantages of our made in France products.

Antonin: With all the precision built into the Silk, how is it affected by dings/chips/scratches will it disturb the ride?

Emeric: Well this isn’t unique to the Silk but yes, we see it first and foremost on race foils where we have high speed and minimal cavitation where even a scratch is felt. How disturbed the ride is will depend on how fast you foil and how experienced you are. But generally most people won’t feel scratches. However if you slam into a rock it will likely affect the feel.

Richard: I’d like to point out that depending on the extent of the damage we have the ability to recondition the foil to be like new.

Emeric: It’s an advantage of working with carbon, it’s hard to manufacture the initial piece but once built not only is it strong but it can be refinished easily as long as the core is intact.

Richard: But our ability to recondition foils is not just due to the carbon construction it’s also because we manufacture in France so we can control processes better and not have to ship the product as far.

Antonin: Thanks everyone and I’ll take this moment to tease our upcoming Live that we’ll do with Chipri to discuss his new Chipri Pro board which hasn’t officially launched yet but is leaking on the internet.


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