BREAKING BOUNDARIES
Huub’s groundbreaking new Anemoi tri-suit, as worn by Alistair Brownlee and David McNamee, is the result of the latest technology and wind-tunnel testing. We explore the science in more detail
When Britain’s David McNamee secured his second consecutive podium spot at last October’s Ironman World Championships, you had an athlete at the peak of his powers. His 8:01:09 was the third fastest time in Kona history. That is what we, the world’s age-group triathletes, saw. For Dan Bigham, aerodynamicist and 25% of the Huub Wattbike track team, his view was something different. “David wore the latest version of the Huub Anemoi suit,” says one of the key drivers of the suit. “We’re proud of it and it saves 15 watts (W) over our DS Long Course suit.”
McNamee’s Anemoi tri-suit is a far cry from 1989’s Iron War where Mark Allen and Dave Scott battled it out in flouncy shorts and singlets. Allen edged it that day in 8:09:15, some 8mins-plus slower than McNamee. Co-incidentally, according to testing by Bigham, that’s how much time an age-grouper averaging an admittedly pedestrian 20km/h would save wearing the Anemoi compared to a traditional tri-suit. It’d still mean said triathlete would be riding for 9hrs but it does highlight that, despite the £290 price tag, Huub is aiming the Anemoi at all levels of triathlete.
“Aerodynamics actually matter more for slower riders,” says Bigham. “In simple terms, slower riders will see a bigger reduction in their bike split for a given change of co-efficient of drag (CdA). Faster riders will see a bigger aero gain but less reduction in absolute time. In our testing, a rider averaging 40km/h over a 180km Ironman bike leg, for instance, saved over 4mins with the Anemoi suit.”
rider’s co-efficient of drag,” Bigham answers, “and is key to helping aerodynamicists like me make triathletes and riders faster.”
Aerodynamic drag is the air resistance attributed to an object. That figure is a product of an object’s drag co-efficient (Cd), or ‘slippiness’, and its size – in particular, its frontal area (A). Drag is simply those two figures multiplied. CdA ranges upwards of zero. Physics dictates that an object with a drag coefficient of zero can’t exist. Something that’s very much real are teardrop-shaped bars, which can register a figure of 0.005. That’s aero. A brick might be 2.0. Not surprisingly, that’s not aero. CdA examples of elites using aero-shaped bars might come in at the 0.18-0.25 mark. For a good amateur triathlete, that’d be more like 0.25-0.30.
It’s one thing knowing the theory, of course; it’s another to research, design and manufacture a technical suit that’s purporting to be the most aerodynamic around. Is Bigham happy to reveal all in the name of sharing and evolving science? “What I can say is the fabrics were benchmarked and have been tested in isolation, as well as using different joining techniques that aren’t currently utilised in the world of cycle clothing. It’s been fun trying new solutions because of techniques Dean [Jackson, founder of Huub] has brought to the party.”
Intellectual property equates to competitive advantage. Here’s what we do know about the broader aero checklist of the Anemoi. “Beyond the aero fabrics and clever use of those fabrics, it incorporates our patent-pending Neoprene Trip technology,” explains Jackson. “The seams are low friction, too, but it maintains the comfort you’re after for all-day efforts.”
AERO CREDENTIALS
Comfort is a bonus in the world of aero tri-suits as, well, their main remit is aero. To that end, Bigham sent 220 data showing a range of drag-wattage and time savings (over Ironman) at various average speeds. For instance, 2W and 6:39mins saved when riding at 25kph; 4.14W and 5:12mins saved at 32kph. We couldn’t substantiate the data. But we can substantiate Bigham’s credentials. At Oxford University, he studied motorsport engineering. That led to 13 months working as a junior aerodynamicist for the Mercedes AMG Petronas F1 team.
If you listen to the Cycling Podcast (late January 2019 episode), co-host Richard Moore spends a day with the Huub WattBike team, the UCI track team who won World Championship, World Cup and national titles in 2018. Bigham’s teammates label him ‘Sleepy Dan’ over his propensity to fall asleep in the wind-tunnel on the night shift. But that shut-eye, plus his own age-group triathlon experiences, awoke a desire to create the fastest triathlon and cycling clothing around, and led to some pretty heavy number-crunching.
“We collated a huge range of race data from triathletes – short, middle and long course; male and female; and age-group right up to Olympic champions,” Bigham explains. “From this dataset, we set about investigating every aspect of the rider’s bike leg, from variables such as velocity profile, drag coefficient and yaw angles, through to Reynolds Numbers – the parameter for predicting if a flow condition will be laminar or turbulent…”
NO BOUNDARIES
Explanation needed. Key to any tri-suit’s aero efficacy is something known as the boundary layer. This is a thin (1-4mm) layer of air that flows over your body while either cycling or running. “Typically, it flows in a laminar state with minimal
energy in the flow, and can quite easily separate off the body around curvature and changes in shape, creating a large draggy wake behind. Yet, using correctly sized and shaped texture, we can induce the boundary layer to turn into a turbulent state.”
This turbulence sounds counter-intuitive. Stirring up air surely creates more drag, not less? “Not so,” answers Bigham. “The advantage of this is that the boundary layer is now energised and can resist changes in curvature and shape around the body, staying attached for longer and reducing the size of any low-pressure wakes.”
Bigham does concede, however, that turbulent flow isn’t all good. It also increases skin friction, which is why fabric choice and placement needs to be strategic. “From the first round of aerodynamic testing, we found one fabric to be performing consistently the best and continued to iterate the design, changing seam lines, seam type and pattern shape to improve the suit,” he says. “Over the next six months, we went through countless prototypes and countless hours of velodrome testing.”
Velodrome testing is growing in popularity and, due to its real-life data, is arguably more important than wind-tunnel testing. This author recently spent time with WorldTour cycling team Astana, who told us they’d used Notio Konect, essentially a sensor that sits beneath your aerobars and features a pilot tube – what you see poking out of the nose cone of aircraft – to measure, among many variables, wind speed. It compares this with a rider’s speed to estimate CdA. Then there’s the LEOMO Type-R, another high-tech sensor that measures your biomechanics in real time.
“We used my own test system that I developed back in university and have been refining ever since,” says Bigham. “In simple terms, it involves a rider riding around a velodrome with a power meter and a wheel speed sensor, but the refinement has added a few more sensors and some more complex maths to improve our control and measurement of certain variables.”
POTENTIAL GAME-CHANGER
Ongoing feedback from age-group triathletes and the likes of McNamee (pictured right) and two-time Olympic Games champion Alistair Brownlee has helped make the science come alive. They’ll no doubt employ Huub’s new cycling collection for training, which features the full gamut, from bib longs to thermal jacket, gilet to arm warmers, all seemingly combining practicality with an aero edge – in this case thanks to CFD (computational fluid dynamics) work by TotalSim.
TotalSim has worked with F1, sailing, cycling… all sports that are seeking an aero edge. TotalSim’s Rob Lewis once worked on something called ‘the dangler’ for British Cycling. Essentially, this was an aero helmet with a piece of string and ball attached, both hanging in front of the rider. The idea was that while there might be a localised loss due to disrupted airflow, it might lead to net gains once the air reached the helmet. It didn’t take off but it did determine optimum bike computer placements. British Cycling also toyed with ideas like sewing sequins into skinsuits to disrupt airflow. We never witnessed Wiggins dressed like Liberace but it highlights how gamechangers, like those who created tri-bikes, aerobars and even elastic laces, often work through a pasteboard of seemingly wild and wacky ideas. Bigham?
“Not too wacky but there’s a great picture somewhere of Dean [Jackson] holding David [McNamee] on the bike in a very compromising position with seamstress Sally, who’s marking and pinning the suit for pattern adaptations,” Bigham laughs.
Whether the development process catered for durability remains to be seen but Bigham’s confident the Anemoi’s lifespan is “very good”. Which brings us to the future for trisuits. “I think bespoke items based on data from 3D scanning is the next step,’” concludes Bigham. “There are simple ways of doing this right now, but without letting out too much to our competitors, there are better solutions that’ll result in a faster product for customers. Bespoke fabrics are coming to the fore. It’s something we utilise for our Huub track supersuit and they’ll be coming to the world of tri very soon.”