As you may remember, back in January I announced the end of Project Cedrus Classic models to make some much needed updates to a mast designed in 2017. It was simply impossible to manage custom carbon mast production while also fulfilling growing aluminum mast, adapter, and fuselage orders. More importantly, I wanted to focus, and I did. I gave myself 9-12 months, which is a pretty aggressive timeline to design and build not one, but two masts, in a post-COVID world/supply chain. For 6 months, I ate/slept/breathed mast design. I worked with industrial designers, CFD specialists, and ran hundreds of FEA simulations and poured over details in CAD. While a lot of ideas had been stewing in my head for the last few years, it’s the final act of detailed design that takes the majority of the time. I estimated at least 1,000 hours of design work went into the masts from January until kicking off tooling in April. The thing with making carbon things that most fail to grasp, is that it’s not just the design of the carbon “thing” that takes so much time and money; it’s the design of all the tooling, the things you need to make the thing, that really drives the cost. I spent nearly every dollar in profit from last year on software, tooling, molds, fixtures, patents, and other assets to make Evolution Cedrus. My wife quit her job, to take some of the load off me when I needed help the most. And I hate to use the terms “quit job” because honestly being a full time parent is the hardest job there is. I want to thank those who helped me, from the clients who’ve given me the emotional support to keep investing to my technicians who literally ground elbow grease into molds, thank you. Making these masts has been one of the hardest things I have ever done, and I could not have done it without you. Kris, Devin, Guy, Glen, Jim, Brian, Chuck, Eli, Barrett, Ariel, Jake… and the late Tom Speer; it has been a pleasure and honor to work with you, and I am forever grateful for your help and support.
As some of you may remember, back in January I posted a survey on my site and across forums, and got a lot of really good feedback from both Cedrus riders and non-riders. While I have a lot of data on what’s popular with my clients (lengths, adapters, etc), I wanted to get further insight from those not riding a Cedrus. The feedback was incredibly helpful; I read every single comment (sometimes to my disappointment) and analyzed all of the data. I took it very seriously, and directly incorporated it all into Evolution Cedrus. I hope you are happy with the results, and thanks again to those who positively contributed to the design.
Ideal Mast Lengths, According to You.
Foiling has evolved so much since I started prototyping masts in my kitchen in 2016. There are new forms of foiling, new wings, new boards, new tricks, and new mast lengths. 7 years ago, 90cm was the standard. Prone foiling didn’t really exist yet, but I made a couple short masts for my prone curious kite-foiling friends. By 2021. prone and wing were in full force, and the average length dropped considerably, to between 70-80cm. Now, we’re seeing longer length masts again, as skills and equipment evolve I’m getting requests for longer length masts regardless of the form of foiling. But the trend I noticed is that longer masts are typically ridden at higher speeds, in choppier water, and therefore have a different set of design requirements than shorter masts which are usually operating at lower speeds but more sensitive to drag. For example, many of my wing foiling clients don’t notice any additional drag when switching to Cedrus from a thinner but more flexible OEM mast. But, they are the ones who typically suffer from ventilation and then order a fence. My prone clients are much more sensitive to drag, so satisfying them requires a different approach to the design. I wanted to share the data with you, and my thoughts behind the model line: Evolution Surf and Evolution Wind.
Evolution Wind Initial Notes
The #1 request from riders and non-Cedrus riders, and indirectly related to the second most popular request, was high speed performance. Higher speeds are achieved when using kites, wings, or riding high energy waves thanks to tow-in or offshore down-winding. In these conditions, you have forces to help you overcome drag. Performance at speed really requires two things: stiffness to handle the increased dynamic loads, and ventilation resistance. Ventilation is a complex phenomenon, and we’ve written about it extensively on our blog since 2018. We’ve had emails from people all over the world asking us to print fences for their non-Cedrus mast, so we know it’s a problem with a lot of masts. It’s a common belief that the thickness/chord ratio (t/c) has the biggest impact on ventilation resistance. This is one reason why the industry tapers masts and makes them thinner, with the other reason being a general misunderstanding of applied loads. Reducing thickness and chord length along the length of the mast has a profound impact on stiffness, especially torsion, which is more critical in the longer length masts that are typically used at higher speeds. Tapering a mast has a two-fold negative impact on ventilation resistance: less wetted area for the flow to stay attached where you need it most, and more mast twisting which promotes flow separation. So we took an entirely different approach to improving ventilation resistance. Rather than focus the numerator of the ratio (thickness) to reduce t/c, we addressed the other side of the equation: chord length. This enables a profile of the same thickness to be much more ventilation resistant. This longer chord length mid-span has a huge impact on torsional stiffness where it’s most important. This reduces the likelihood of structurally-induced ventilation but it also becomes extremely difficult to separate the flow from the mast where it’s piercing the water due to the increased wetted area and surface tension. No one has ever made a mast like this, and I’m sure some of you are still scratching your heads as to why one would design a mast that not only doesn’t taper, but tapers almost in the opposite direction! I remember the first time I saw reverse camber (otherwise known as rockered) powder skis, and as a quick to judge retired ski racer, I thought it was an abomination! But I’ll never forget the first time I rode my first pair of Rossignol S7s – they were so much more forgiving and playful in the powder, so much so that they completely changed the industry and even all-mountain skis now feature early rise at the tip and tail, instead of traditional camber throughout the length. Evolution Wind will be no different: It will offer unmatched stability at speed thanks to extreme ventilation resistance at the water-piercing region. The lower chord length and thicker section up high reduces drag and further increases stiffness compared to more traditionally shaped masts, which add fairly useless and draggy chord length where thickness is needed most. The patented design of Evolution Wind features 16mm thickness throughout the piercing and submerged region of the mast, for much lower spray and parasitic drag than the Classic. The 20mm thickness above and at the fuselage interface increases strength where masts are prone to flexing and fracturing. The variable chord length between 120mm and 130mm will sum up to a mast with less drag than the original Project Cedrus, but unmatched predictability and stability at speeds for the most confidence-inspiring rides.
Evolution Surf Sizing (FEA)
The third most popular request was to improve low speed performance. In the survey, I defined low-speed performance as 5-15kts and relevant to dock starting, small-wave prone foiling, or light wind kiting (my personal favorite). We hear the term “glide” a lot in reference to these types of foiling. In this case, without any forces to help overcome drag, we have to focus on minimizing it. As I’ve discussed many times, thickness has only a minor impact on drag, so thinning the mast can only buy so much drag reduction, at a huge expense to stiffness. No matter how high the modulus, or how solid the laminate, a 14mm thick mast can never match the stiffness of 16mm. That is not a tradeoff we’re willing to make for a 13% drag reduction. Chord length impacts drag with over twice the effect of thickness, due to the reduction of wetted area, but as discussed above, it’s also helpful in reducing ventilation. So the mast designed for high speed performance isn’t really optimal for low speed, where ventilation is much less likely to occur and torsional stiffness is also less critical due to the inherently shorter lengths of the masts and lower dynamic loads. This was when I realized we needed two different masts: one design for high speed/longer lengths, and another optimized for shorter lengths and lower speeds. This was also a moment I walked down to my local bank and took a line of credit since my tooling costs effectively doubled. But by cutting chord length in the middle of the mast, we effectively reduce thickness to <10mm (for the same chord length), without cutting stiffness by an order of magnitude. Now you might be saying wait, when designing Evolution Wind you talked about t/c ratio having a huge impact on ventilation resistance, and you’re right. But the original Project Cedrus has a t/c of 15.8, and ventilation was not really a problem for my prone and pump foilers. Ventilation really requires higher speeds, more aggressive angles of an attack relative to wind, and is further promoted by choppier waters. However, thanks to a thinner water-piercing mid-section at 16mm, even reducing chord length to 110mm leaves Evolution Surf with a t/c 14.5, which is in line with masts typically not associated with ventilation issues and based on CFD, half as likely to ventilate as the original classic. Evolution Surf probably looks much more traditional to you, and in a way it is. But note that due to massive torsional and rolling loads coming in from modern foil wings, we bumped thickness up at the adapter/fuselage interface to improve stiffness/strength in an area where a lot of masts flex or crack. Despite this thicker region, ventilation is impossible to initiate here because it’s so far below the surface. The variable profile of Evolution Cedrus will result in industry-leading glide characteristics with the Cedrus stiffness you are accustomed to, perfect for small-mid wave prone foiling, pumping, or other forms of light wind riding. If ventilation wasn’t a problem for you on the Classic, or similar mast profiles like the Axis 19mm Aluminum, then you’ll definitely be happy with Evolution Surf, as again it’s even less prone to ventilating than either of these. But if you’re planning to wing and push the mast hard upwind, or run downwind in more confused seas, you may prefer the added ventilation insurance of the longer chord length found in Evolution Wind. Evolution Surf is available up to 90cm assembled, while the shortest Evolution Wind can be configured to a bit above 80cm with a direct-mount fuselage. The overlap in sizes gives you the option to tailor your desired performance characteristics depending on your preferred form of foiling-it’s up to you to balance the tradeoff between glide and speed, which is what many of you have asked for.
Just one of the crazy concepts we explored…
The final request from the survey was to improve adapter design/usability/performance. While the current design works really well for most foilers, there have been a few corner cases that are difficult and frustrating for both me and my clients. I mean it’s a tall order, as many OEM fuselage connections leave a disappointing experience. Designing and manufacturing a universal adapter system is one of the hardest things I’ve ever had to do in a career full of pretty challenging things (787 Dreamliner, iPad Pro, and pallet-sized vacuum chambers to name a few). Most issues were related to inadequately torqued fasteners, but it was also possible for bigger riders/wings/boards to overload the system. Sometimes the mating fastener spacing makes it difficult to design an adapter around, or it’s simply impossible (and the best solution is a whole fuselage eg. Armstrong, GoFoil). I believe firmly based on first principles and 6 years of designing adapters that two flat and planar mating surfaces held together with strong hardware is the best type of joint for foil equipment, far more reliable and easier to manufacture than these tapered connections that wear, bottom out, and suffer from tolerance issues. But together with my machinist we explored a number of other options. From tongue and groove joints, to tapered fits, to mortise and tenons, and even set screws. But none of them really allowed us to stay within the design envelope at the bottom end of a foil mast, all were more expensive, and more likely to suffer from wear. What we landed on is a super elegant, functional, and cost effective way of increasing adapter strength, reducing hardware loads, and improved overall stiffness. It also offers a lot more flexibility in adapter design, reducing offset and ensuring a more OEM-like adapter placement. The patent-pending design features two 10mm stainless pins that manage the primary yaw, roll, and even tensile loads from the fuselage. The precision of these slip fit joints is unmatched in the industry, achievable only with few CNC machines. Two custom M8 screws ensure everything stays together, and the resulting system is about 50% stronger than the original Classic adapter interface. Adapters will stay better aligned with the mast, and hardware is less likely to loosen thanks to reduced bending loads in the screws. For direct fuselage connections, there are 3 threaded M8 holes in the mast which offer equivalent strength to the dowel pin connection without the added complexity and cost. So if any brands want to design Cedrus-specific fuselages, it’s super easy.
The compromises you asked for
As we’ve discussed extensively, when it comes to multidisciplinary optimization, there are always tradeoffs. But just like we asked what you wanted in Evolution Cedrus, we asked what were you willing to give up from the Classic. Well, it was pretty unanimous: weight and cost. Fortunately, thanks to some innovative design and manufacturing techniques, we were able to keep the weight gain minimal. Evolution Cedrus is only about 10% heavier than the Classic, so it’s still one of the lightest masts on the market. Much lighter than the solid HM masts. But to achieve the faster profile and maintain the industry leading stiffness and strength, we needed more plies of carbon, which means more material and labor… and cost. This coupled with the doubling of our tooling (molds, fixtures, and jigs for two mast models), and general increase in all material costs from aluminum to epoxy, means we have to raise the price from the Classic levels. This puts Evolution Cedrus at similar pricing levels to other “high performance masts” but with the added value of custom lengths and complete universality, with the Cedrus quality, reliability, and service that you are accustomed to.
Hopefully we’ve made what you’ve been waiting for!
In closing, it was fun incorporating some of the other feature requests you made on the survey. Note that the bottom insert/adapter interface is now entirely over-molded, making it invisible and far less prone to abrasion from sand which has in some cases led to corrosion or paint flaking. We still advise you to always remove carbon fiber fuselages when storing your mast, as it will reduce galvanic corrosion within the adapter interface. We’re also excited to offer custom 6AL-4V hardware with mounts and adapters, which is the only grade of Titanium that is stronger than our A4-80 stainless machine screws. These will feature a much requested T40 driver, which coupled with Titanium’s increased corrosion resistance, is much less likely to strip. Finally, we’ve addressed requests for longer length masts, with Evolution Wind available in assembled lengths up to 108cm. However to maintain stiffness in shorter length masts, we’ve limited the shortest Evolution Surf to an assembled length of 70cm. We simply weren’t open to reducing performance across the range of the mast line in order to achieve lengths shorter than 70cm, of which we have sold very few over the last 5 years. For those looking for masts shorter than 70cm, the custom aluminum mast is a great and economical option, with very little weight penalty. Both Evolution Surf and Wind feature the same adapter connection, and we’re still working out details on mounts. Despite offering the first carbon mast with a removable mount, allowing clients to share between multiple sizes/models, we’re typically seeing a high attachment rate to the mast. It appears most clients prefer to have a mount coupled to the mast ready at all times, so we’re likely going to design specific mounts for Evolution Wind and Surf which allow us to make fewer compromises on the design side.
There is a very limited batch of Launch Customer masts available for purchase, with a delivery between November and December. We’re moving into a new facility in January, continuing to grow and train our team, and hoping to begin mass production in February with a 4-week leadtime on custom orders. Thanks again for all the support, and we look forward to building you an Evolution Cedrus soon!
Kyle
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