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Annemiek van Vleuten’s world championship win was a remarkable show of tenacity and a perfectly timed attack. World title, fractured elbow, and incredible tenacity aside, Van Vleuten’s socks were another high point of the elite women’s world title decider – pun intended – which landed the new world champion with a 200 Swiss Franc fine.
As coincidence would have it, we have spent much of this week talking to Dutch sock manufacturer Sockeloen and founder, Jasper Ockeloen, about the benefits of aero socks and the fastest socks on the planet.
Sockeloen has offered a range of aero and standard socks that have lined the shoes of many champions over the past few seasons. Although Ockeloen can not confirm exactly which athletes he provides socks for, there are some key clues that can help you identify the socks. One is the all-white aero-trip design you might have seen back in 2020 on the feet of Mathieu van der Poel. Another is the golden heels inside Michael Matthews’ shoes this summer.
The question is, what makes the Sockeloens so special that pros seek out non-team-edition socks from a small Dutch manufacturer?
The fastest socks on the planet
Sockeloen’s new line of socks is confidently named “Fastest Sock on the Planet ™ (FSOTP)”. Yes, that is the model name.
Sockeloen’s FSOTP are made-to-measure custom aero socks matching the rider’s foot along with the length and the diameter of their calf to ensure the perfect fit. The socks feature aerodynamically optimised and wind tunnel-tested fabrics and textures, and are said to be as fast as their name suggests. Oh yeah, and the FSOTP 540 socks cost a whopping €1,000 per pair (approximately US$970 / AU$1,475).
We recently reported on Antiloper’s €1,850 custom shoes, which seemed like a lot of dough for shoes, but €1,000 for a pair of socks is another level entirely. Sockeloen claims it’s this mix of “perfect fit”, “perfect materials”, and consultancy-like service that sets the FSOTP apart from all the other aero socks currently on the market.
Already offering more traditionally styled and -priced cycling socks, Sockeloen set out earlier this year to develop the fastest aero socks in the world. The sock specialists collaborated with fellow Dutch aero specialists, Speeco, and the Eindhoven University of Technology to develop and wind-tunnel-test more than 10 variations of the FSOTP and competitor aero socks. Sockeloen documented the process and recently released a mini-series on YouTube, even going as far as to set up its own in-house production facility to create more prototypes quicker.
Sockeloen claims its testing and development process has helped the brand understand the key properties of the perfect aero sock. But, despite the sock name, the result of said process is not one “fastest sock on the planet” but rather three different socks. And all are said to be the fastest, depending on target speed.
As Ockeloen explained, “the fastest sock at 60 km/h will be different to the fastest sock at 54 km/h, while another sock will perform better at 46 km/h.” As such, Sockeloen varies both the material and the textured surface in each of its three fastest socks to meet the aero requirements of varying speed ranges.
Following the specific materials and texture, an exact sock fit is said to be the next most important aspect of a truly fast aero sock. Sockeloen explains the fastest sock must fit perfectly to the leg, ensuring the material and texture structures are unchanged, and the sock stays perfectly in place. Maximising the sock length within the UCI rules is also key to the perfect fit and aero advantages.
“While riders can stretch any sock, doing so will harm the aerodynamic advantages of the material,” Ockeloen explained. Ockeloen claims this perfect fit for rider and material is only possible with a made-to-measure sock.
Because our mission is to be the fastest, our plan was to develop as many samples as possible. We see every sample as an opportunity for the fastest sock. The more samples, the more opportunities. We have worked out all the concepts we could come up with.Sockeloen
Still, €1,000 seems a lot of money for a tailor-made skinsuit, let alone a pair of aero socks. However, Ockeloen explains that riders get more than a pair of socks for their money. “Think of this as a consultancy service and a performance guarantee based around creating the fastest sock on the planet for the specific individual,” Ockeloen said.
Sockeloen first assesses the rider’s current socks, the exact demands of the target race, and their unique fit. From there, it creates the first custom samples based on its experience in creating aero socks, before taking the customer into the wind tunnel to perfect the final product and prove that performance guarantee.
It’s then back to Sockeloen’s in-house production facility, where it carries out all the sublimation, knitting, cutting, and design to create the custom aero socks. And yes, it’s possible to go through all of this and order just one pair.
This all said, riders can skip the wind tunnel testing and refinement process, which brings the price down considerably to between €50 and €150, depending on the quantity ordered. Ockeloen explains it’s this custom process minus the testing that most professional riders sporting the FSOTP socks have opted for.
“Given their busy race schedule, we made many socks for pros based on their leg sizes measured at home,” he said. “We can add team logo designs or do all white, depending on their preference. Just search for a golden heel, and you’ll find our babies.”
How fast is the fastest?
As mentioned earlier, Sockeloen wind tunnel-tested its FSOTP socks against several competitor aero socks. Before delving into the results, it is worth noting all the testing was conducted at 0º yaw, a yaw angle rarely experienced outdoors, and with a stationary mannequin. Sockeloen explains it doesn’t believe riders will choose socks depending on wind direction and preferred to test more socks over one yaw angle, than fewer socks over many yaw angles.
The stationary mannequin helped eliminate the variability between tests that are inevitable with real-life humans, but the company also admits the stationary legs are not a true reflection of a rider in the real world. There are pros and cons to many wind tunnel tests, but Sockeleon is planning subsequent testing across a range of yaw angles.
With its three new FSOTP offerings, Sockleoen claims it now has the fastest sock on the market at 40 km/h, 47 km/h, 54 km/h, and 61 km/h. The brand’s existing aero socks already proved fastest in its testing at 40 km/h, but the new socks expand that honour across the three higher speed ranges.
Compared to other common aero socks at 47 km/h, Sockeloen claims its socks are 3.6 watts faster than the DeFeet aero offering, 5 watts faster than ACG’s aero socks, and 3.6 watts faster than AGU’s. The full testing report and results are available through the Sockeloen website.
While Sockeloen didn’t test its socks against aero overshoes, it does believe its socks, with the right shoes, can prove faster than even aero-time trial overshoes. The brand even goes so far as to suggest we look at Annemiek van Vleuten’s time trial combination as an example. That was before the controversy with Van Vleuten’s high road race socks. And although the socks from both events appear remarkably similar, apart from the obvious height difference, Sockeloen was quick to distance itself from the new world champion’s tall socks seen in the road race.
But is more sock, better sock?
Of course, given recent events, we couldn’t do such an article without mentioning AVV’s tall socks. The UCI mandates that “socks and overshoes used in competition may not rise above the height defined by half the distance between the middle of the lateral malleolus and the middle of the fibula head,” and Van Vleuten received a fine for her world championships socks. As mentioned earlier, Sockeloen makes its socks to fit perfectly to that halfway mark for each rider’s individual leg length, maximising the aerodynamic advantage offered by the sock.
That said, Sockeloen has made longer socks and “aero tubes” for triathletes, explaining “we did that, but we’re not a big fan of the aesthetics of such tall socks.” As for how much difference knee-high socks might make, Sockeloen claims a triathlete, presumably in a somewhat aero position, switching from no socks to their knee-high socks achieved a 3% reduction in total system aerodynamic drag. If true, it’s a saving that seems relatively huge for just a simple sock change.
However, Sockeloen was keen to stress the socks must still fit perfectly. “We also tested UCI legal socks stretched up to knee height and found no additional aero gains. This is because the stretching deforms the specific textures and negates the aero properties of the socks.”
Regardless of the gains or Van Vleuten’s win, let’s hope extra-tall socks are not a new trend.