In October 2019 Eliud Kipchoge became the first human to run a marathon in under two hours. While some scoffed at the time achieved outside IAAF regulations, it was Kipchoge’s shoes that caused a lasting stir.
Runners will know of the controversy the so-called “super shoes” Kipchoge ran in – Nike’s Zoom X Alphafly – created given the claimed 4% performance bump seemingly any runner could achieve just by slipping into the costly slippers. While such performance claims are often mere marketing gimmicks, this time it was different, and what to do about those “super shoes” with their carbon fiber sole plates and energy-conserving foams – and the countless competitors that followed in their wake – became a nightmare for the IAAF and IOC.
Little did we know, cycling already had its super shoe, or more accurately, “super suit” moment, earlier that year when Team Ineos (as it was then known) riders raced with the powerfully drag-reducing “dual-layer technology” in their skinsuits at the British National Time Trial Championships.
The hotly debated fabric technology is considered to offer at least a 5% gain (roughly 45 seconds in a time trial of similar – 42 km – distance, or potentially the difference between a low-end TT bike and a premium, modern setup) and sources Escape Collective spoke to contend they are already deciding the destination of 2024 Olympic medals on the track. But that 2019 race, and others since, also landed Ineos in a patent war and legal battle as experts debated what exactly constitutes a so-called dual layer suit and who owns it.
Layered gains
The so-called dual-layer technology refers to an aerodynamic intervention and is available in two forms: first is the more affordable and increasingly common “aero base layer” with rib-like structures usually most notable on the upper arm and worn beneath a race suit. Such combinations are now common practice in the pro peloton and are the original take on the dual-layer intervention.
But a second, much more expensive, highly customised, and seemingly more effective version first used by a select few in the Tokyo Olympics is now commonplace in the Paris Olympics: integrated dual-layer suits.
Dual-layer suits follow a similar concept to the suit-plus-base layer approach but instead build the aero-optimised structures into the skinsuit, making a garment with double-layer sections added to strategic locations with highly precise dimensions for what are seemingly the fastest suits currently available. Unlike the super shoes considered costly at £400 or so, you’ll need to fork out anywhere between £3,000-£7,500 / US$3,800-$9,500 for these super suits.
Once considered an aerodynamic “cheat code” reserved for only the wealthiest and most astute teams, Olympic nations, and connected riders, as the Paris Olympics unfold, one thing is clear: the hyper-expensive and individually optimised dual-layer suits are “everywhere” according to our sources.
According to Mehdi Kordi PhD, Head of Sprint Performance/Coach at the KNWU, the Dutch cycling federation, it’s the “dual-layer Olympics” and those who don’t have it can almost say goodbye to any chance of gold in the velodrome. And just as some nations are spending thousands to catch up, others are licensing the technology and layering their own interventions onto other areas of the suit for even greater gains – not only in track racing but other Olympic disciplines as well.
Vorteq, a Silverstone, England-based company that manufactures the double-layer suits and a subsidiary of TotalSim LTD, which owns a patent on the technology, claims its suit (and overshoes) will be used by close to 100 individual athletes representing 14 nations across 10 cycling events in track, road and BMX in Paris. Vorteq says it has manufactured over 100 suits and close to the same number of pairs of overshoes specifically for these Olympic and Paralympic Games.
That’s not counting the various riders and nations who will race with other manufacturers’ takes on the same concept used on license from TotalSim – all to varying degrees of effectiveness, according to experts Escape Collective spoke to.
While those experts all agree both takes on the dual-layer concept are hugely beneficial, offering anything from 5-10% reductions in total system (rider and bike) CdA – for comparison, the new Pinarello Dogma F is claiming just a 0.2% reduction in total CdA from the previous version – they seemingly cannot agree on why such suits provide such huge gains or even what constitutes double-layer technology.
As mentioned above, that disagreement led to TotalSim bringing legal proceedings against the Ineos Grenadiers last year for what it considered unlicensed use of the technology. But fast forward to this summer’s Olympic Games, and the same dual-layer technology is now commonplace and deciding medals. So what gives?
If everyone has dual layer, no one has dual layer?
The common wisdom in sports science is that if everyone is using an advantageous technology, effectively no one is. Is that the case here? Not quite. With the rider making up around 80% of the aerodynamic drag on the total bike and rider system, and skinsuits covering a large proportion of a rider’s body, it’s not surprising there are huge time savings available in getting the skinsuit right. But, what is “right” differs greatly from one rider or event to the next.
For years, “right” meant producing a suit so tight that riders could have had a second career as escape artists attempting the seemingly impossible act of first getting into the tiny suits, often requiring assistance from a support staffer, and later the equally difficult act of getting out of them.
More recently, we’ve seen trip strips, then surface textures, and now rib-like structures appear most often on the upper arms but also in various other places on some suits. Many of these ribs and textured surfaces sit atop the outside of the suit, but the dual-layer approach sees them fitted under an outer smooth surface, either as a base layer or integrated into the suit.
Regardless of the exact makeup, all these interventions are hoping to create the same effect: reduced drag. The arm is a cylindrical structure that creates a lot of drag. Counterintuitively, turbulent airflow over the arm will create less total drag than smooth laminar flow, and so all these interventions are designed to induce controlled turbulance.
How so? Examined in isolation, laminar flow creates less drag than turbulent flow, but laminar flow builds up as it travels over an object – a cylindrical-ish upper arm in this case – creating a thicker boundary layer, or the thin layer of air that forms along the surface of the rider. When the arm’s cylindrical shape inevitably forces this thicker boundary layer to turn turbulent and detach, this larger build-up of flow results in a larger “wake” behind the arm/rider. The wake is a region of low-pressure, turbulent flow that recircles behind a moving body, characterised by reduced flow velocity and vortices resulting in greatly increased suction drag, effectively holding the rider back from behind.
Enter the textures, trip strips, and ribs we see on modern aero clothing. These structures and textures help transition the flow over the arm or body from laminar to turbulent earlier, reducing the boundary layer build-up, helping it stay attached to the arm longer, and thus minimising the wake behind the arm and overall aero drag. The smaller wake means a smaller low-pressure zone behind the arm, which in turn means a reduction in the low-pressure suction drag behind the arm, or in other words, the surface textures on the front of your arm result in less of the invisible, speed-sapping drag behind the arm.
There’s a catch, though: It’s not just fit and forget. The exact width, height and spacing of these flow-tripping and wake-reducing interventions are critical to their effectiveness and highly dependent on speed and the exact size and shape of each individual rider’s arms (or other body parts). It all depends on what’s known as the Reynolds number, a dimensionless quantity accounting for the density, velocity, and the dynamic and kinematic viscosity of the fluid (air in this case) and the length of the body it is travelling over. Long story short, the Reynolds number helps predict if the flow over an object will be laminar or turbulent with low Re numbers (<2000) indicating laminar flow, and high (>4000) indicating turbulent. But for cyclists and the speeds at which they travel, their arms, bodies, helmets, and other elements typically sit between the two in a range know as “transitional flow.” That’s what dual-layer technology aims to address.
A 15-year-old innovation comes of age
TotalSim Ltd, a computational fluid dynamics (CFD) specialist company founded in 2007 and based in Silverstone, own the patent to these integrated dual-layer suits, and while they license that patent to other clothing manufacturers, Vorteq (as mentioned above) is a TotalSim subsidiary. While Vorteq’s work is evident when you know what to look out for, you may never see the company’s name or logo as it’s most often putting other manufacturers’ labels and logos on its creations, manufacturing skinsuits and overshoes for numerous Olympic and WorldTour teams and riders.
It’s Vorteq that has seen this almost decade-old concept transform into a hyper-precise, expensive and individualised offering: an intervention that is barely noticeable to the untrained eye and yet powerfully effective, making it the must-have suit in Paris. Past the velodrome, Vorteq’s work has already crept into road racing in the past few seasons as riders and specialists as diverse as climber Simon Yates and sprinter Jasper Phillipsen have already used its dual-layer suits in winning Grand Tour stages, although licensing agreements prohibit Vorteq from confirming exactly who they’ve worked with.
It’s not exactly new on track either, having already debuted in the Toyko 2020 Games officially used by the Malaysian team, while Ashton Lambie used a dual-layer Vorteq suit in setting a new Individual Pursuit world record soon after those Games. It’s in reviewing these seemingly sporadic results in recent years and comparing them to the widespread uptake in Paris it seems there was a clamor, perhaps even an element of technical coercion, among teams and manufacturers to get their riders into the fast fabrics.
While the surge in interest is relatively new, the technology itself is not. Luca Oggiano is CEO and founder of NablaFlow and developed the company’s CFD AeroCloud software many bike manufacturers are now using. But Oggiano, who has a PhD in textile aerodynamics, first experimented with dual-layer aero base layers and suits as far back as 2010, initially with 100-meter and 200-meter track and field athletes for Adidas. Oggiano explained he first brought dual-layer combinations into the WorldTour with Team Ineos and Filippo Ganna in 2019 and claims the base layer-plus-suit combination is just as fast as the integrated dual layers.
Vorteq, on the other hand, claims that because its outer layer (or membrane) is suspended above the inner layer by the aforementioned rib-like strips, its built-in dual-layer suits reduce the chances of a rider positioning the ribs, textures, and structures incorrectly or too tightly. Furthermore, they claim that because it’s not the textures or ribs doing the work in their concept, its suits offer “omnidirectional drag reduction.” In other words, Vorteq claims the benefits of its suits are not limited to specific conditions.
On the face of it, both takes are seemingly the same thing, but where others point to the surface textures and ribs as the key to creating a drag-reducing stall effect, Vorteq claims the ribs in its suits are in fact just support members for its outer-layer membrane. Vorteq says that outer layer, which is also very smooth, is suspended at the perfect tension – not too tight and not too loose – and thus free to oscillate as the flow travels over it, allowing it to alternate between passive and active states. Vorteq claims it’s this oscillation that induces a “drag crisis,” a phenomenon in which drag drops off suddenly as the Reynolds number increases.
Specifically, according to the TotalSim patent, the ribs define a series of spaced support formations effectively suspending the outer fabric layer, allowing it to dynamically switch between a passive configuration where it does not alter fluid flow and an active configuration where it initiates turbulent flow to reduce drag. In Vorteq’s words, while other dimpled or roughened surface aero interventions provide modest drag reduction in specific conditions and orientations, its dual-layer suit can adaptively minimise drag regardless of the flow direction or Reynolds numbers.
Oggiano agrees the specific micro textures of the correct external fabric paired with specific macro structures built into a base layer make for a potent drag-reducing combination, but disagrees those gains come from oscillations in the fabrics, and contends good base layer-plus-suit combinations are just as effective. For Oggiano, the aero wizardry comes from the sub-layer ribs and textures themselves and the surface roughness they create on the smooth external layer, almost like the inverse of the dimples on a golf ball.
With so much confusion, we asked Jacob Tipper, Head of Cycling at Huub, to rank the various options for us. While it’s very much an “it depends” question, Tipper suggests the biggest gains are realised in the initial step from a standard suit to any well-fitted or customised modern aero-optimised suit, be that single or dual-layer. Everything else being equal, either of the dual-layer approaches should then offer an additional gain over most single-layer suits, but individually customised dual-layer suits, the likes of which we see in Paris, could produce the same gains again, or higher, over even an off-the-peg suit with dual-layer features.
If the suit fits
While other manufacturers Escape Collective spoke with also questioned Vorteq’s claims about oscillation, none argued the Vorteq suits are not fast. Regardless of where exactly the magic lies, the additional steps in creating a Vorteq suit could be just as crucial as any oscillating or textures.
Anyone who has seen a rider in a Vorteq suit but not in their optimal position may scoff at the idea of any drag reductions when they see the loose fitting and often baggy suits hang around the elbows and backside. Vorteq claims that’s kind of the point and that the suits only fit when the rider is “in position.”
The Silverstone-based company 3D-scans each rider in position, allowing them to precisely tailor the suit for the optimal fit, and as it claims, the optimal outer layer tension. These 3D scans are converted into 2D designs for cutting and production, while further testing allows them to precisely position and space the rib structures optimally for each individual in their optimal position at their target race speeds. Vorteq claims this process not only makes for a faster suit but also eliminates any variation it says is likely when a rider wears separate base and outer layers, despite the end result looking similar.
Such is their belief in the technology’s effectiveness, Vorteq offers a “performance guarantee,” which is now based on agreed targets but was, until recently, a 5% minimum reduction in CdA. That’s a significant CdA reduction, roughly the equivalent of moving from a low-mid level TT bike to a modern and ultra-premium superbike. The price tag is equally significant at £7,500 / US$9,500, which includes the 3D scan and four hours of wind tunnel testing of four variations to determine the optimal solution for each individual rider. A skinsuit on its own with just two hours of testing is slightly less costly at £5,250 / US$6,660.
Shining what is perhaps the brightest light yet on the impossible task the UCI faces with its commercialisation and equipment register endevours, the same Vorteq suit is available off the shelf, as required by UCI regulations, priced at £3,000 / US$3,800, and offered in different versions for sprint, endurance time trial and endurance mass-start (ie. Omnium) events.
Given that is the same suit for only slightly more than half the price of the least expensive custom option, the stock suit may seem like a no-brainer. But that’s before you realise that those suits are tailored to some unknown Olympic rider and are not available in off-the-peg small, medium, or large sizes. As such, they’re practically useless to any other rider. In fact, Vorteq recommends riders considering these suits to contact Kalas (or one of their other licensees) for a suit utilising the dual-layer technology but more likely to fit them better.
As such, any riders and teams using Vorteq suits in Paris will have gone through this expensive 3D scanning and wind tunnel testing process. A £7,500 a pop, and with numerous riders on each Vorteq-equipped nation, these costs soon mount up to a rather costly bill, even if we assume some bulk buying discounts.
Imagine then, having invested that money, your nation turns up at the Olympics, and 10 or more others have the same suit, having spent the same investment with the same R&D and manufacturing company.
All that considered, it’s not surprising other manufacturers are sticking with other separate-dual layer options; Castelli, Huub, Rule28, NoPinz and others all offer so-called “aero base layers.”
According to Oggiano, the key reason why dual-layer technology, regardless of the exact construction or make up, is fast is that it allows the fabric structure to be tuned to the specific rider or speed. By having a base layer underneath the outer layer, the surface of the outer layer can be modified in a way that manipulates the flow and reduces drag. Specifically, Oggiano explains that the combination of the base layer and the ribs or textures on the outer layer creates shapes that the airflow “likes,” allowing it to stay attached for longer, reducing the wake and, thus, drag.
Team GB’s sprint athletes’ own social media posts give us a closer look at just how the ribs are tailored for each individual athlete. The three riders in a Team Sprint complete their leg of the race at very different speeds and the second image below shows how that speed difference, plus potentially any differences in the dimensions of their arms requires different spacing between the aero ribs.
The base layer-plus-suit combination is also considerably easier and thus cheaper to manufacture, as such, we have seen a surge in these options over the past couple of years. Seemingly another argument for separate aero base layers is the option to utilise and test macro structures or various dimensions tailored to specific riders and/or speeds.
But the flip side of that is that aero base layers are not just a simple case of copy and paste. The height, width, and spacing of the ribs is critical to overall and individual performance. Most experts Escape Collective spoke to, including Oggiano and Huub’s Jacob Tipper, agree that aero base layers are most often a “safe bet” offering some aero gain for most.
That said, Oggiano did warn that while riders are more likely to “get lucky” (read faster) than “unlucky” (read slower) with an aero base layer, some could be very unlucky and unwittingly make themselves slower by wearing the wrong base layer, a poorly designed base layer, or even the right base layer in the wrong conditions.
Like everything in aerodynamics, aero base layers are highly individual and only testing can truly answer if something is faster or slower for a given athlete.
Super suits are a super business
Regardless of how the technology works, several experts Escape Collective spoke to agree that Vorteq is currently offering the fastest suits available, and “it’s not even close” when it comes to high-speed events like track sprint events. In races won by hundreds of a second, the right suit is worth tenths of a second.
Whatever the method, the riders only care that the suits make them faster. But go-faster kit is becoming big business. We’ve already highlighted some of the prices involved above. As reported by Law360.com, TotalSim Ltd also took legal proceedings last year to defend their patent, having sued Tour Racing Ltd (the parent company of the Ineos Grenadiers team) for patent infringements over a four-year period from the 2019 Tour of Britain to the British Time Trial Championships in 2023.
A document readily available online details TotalSim Ltd’s request for an opinion on the validity of its own patent (number EP3213911B). While requesting an opinion on a patent is a strategic move often undertaken by patent holders for several reasons, in TotalSim Ltd’s case, the specific trigger for the opinion request seems to be linked to concerns raised by Tour Racing Ltd (TRL), who provided documents suggesting that the patent might be invalid based on prior art.
While none of the parties involved would comment on the exact outcome, a Vorteq representative confirmed the case had been settled. Ineos Grenadiers did not respond to a request for comment on the case.
So are super suits bike racing’s version of super shoes? Can riders compete equally with aero base layers, and will the UCI need to intervene? The answer is not simple.
While we have focused on dual-layer suits, it’s important to understand other single-layer concepts do exist and the manufacturers of these likely claim they are just as fast. In fact, some are suggesting had it not been for the UCI’s homologation process mandating all teams used and registered their suits for Paris in competition before a deadline that passed almost 12 months ago, we might have seen newer takes on the single-layer approach on track right now.
The single-layer takes put the surface textures on the exterior of the single layer that makes up the suit. Looking at Lotte Kopecky’s race suit from Sunday’s road race and we can clearly see the strips running the length of the sleeve. Countless manufacturers and brands have adopted similar designs in recent years, working on effectively the same induced turbulence theory.
But, it’s not just the single layer on the comeback. These Games have also seen a return of the high-sheen, seemingly plasticised or rubberised finishes we first saw in the 1980s and have now seen on some Team GB, Italian, and New Zealand riders in both the time trials and track races so far. Once prohibited by the UCI but not written into the current regulations, higher-sheen finishes should prove slipperier for the flow over that section. Again, though, it’s not a slam dunk. As Steve Smith of Castelli explains, such interventions are far from straightforward and may create drag-increasing pressure gradients if applied or positioned incorrectly.
Team GB’s Josh Tarling was one rider wearing a suit with this rubberised or plasticised finish on the back and forearms. Perhaps the most interesting thing about Tarling’s suit is that it also seemed to incorporate a new take on integrated dual-layer technology. While typically, the ribs on Vorteq (or TotalSim licensed dual-layer suits) run straight up and down the upper arm, Tarling’s and Team GB’s suits this year feature a much wavier-style rib structure. Add to that, that Tarling typically wears an aero base layer with ribs running across his back while racing for Ineos Grenadiers but used this new rubber-like back with Team GB and it seems a rider’s own trade team and nation don’t agree on what is fastest for an individual.
All that considered, there seem to be only a few certainties: No one intervention is the fastest for everyone, testing is best, technology marches on, and while dual-layer suits may be the must-have aero intervention in 2024, you can bet your bottom dollar it will be something different in Los Angeles four years from now.
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