Professional road cycling is almost unrecognisable from two decades ago and aerodynamics have been the biggest driving factor behind this image change.
For the bikes, frame and fork tube profiles are wider, deep section aero wheels are commonplace on all-but-mountainous terrain, handlebars and stems have been replaced by all-in-one cockpits, and any cabling is hidden internally to minimise drag.
Elsewhere, every aspect of a rider’s kit has been optimised to aid their slicing through the air – from big, bulbous helmets that sacrifice ventilation and comfort for speed, to skin-hugging suits crafted from a number of different textures that are strategically placed to interact differently depending on the airflow that they encounter.
But after two decades of exponential growth, is there still untapped potential in aerodynamics? Or are we nearing its endgame, where teams, athletes and kit manufacturers are going to have to look elsewhere to get an advantage over competitors?
One person who is better placed than most to say is Dr Rob Lewis. The founder and managing director of TotalSim, Lewis heads up a group that includes the Silverstone Sports Engineering Hub wind tunnel and aero clothing designer Vorteq. One of the pioneers of computer fluid dynamics (CFD) simulation in Formula One in the 1990s, he shifted his focus to include cycling in the early 2000s, becoming an integral part of Chris Boardman’s Secret Squirrel Club in the build up to the 2008 Olympics.
“I think [investment in aerodynamics is] growing and it will continue to grow,” he says. “But what generally will happen is that the gain you get for the spend will flatten out. It might end up like the garden spade – it was optimised 150 years ago, and nobody really makes titanium or carbon fibre spades because they're good enough.”
Before we reach this point, he thinks there’s plenty of untapped drag-reduction up for grabs. From stage-specific skinsuits to integrated shoes and pedals, he shares where he thinks aerodynamics could turn in years to come to keep speeds increasing for the same watt input.
Stage-specific setups
Although each day of a Grand Tour, stage race or one-day classic features different and unique parcours, these are known months in advance. While there are still variables to consider on the day like wind direction and speed, forecasts can predict these ahead of the start. This means that there’s the opportunity to optimise a setup to suit that day’s conditions and course.
“When Formula One goes to a racetrack, they turn up with a car that's optimised for that racetrack, and they choose the level of downforce and drag that optimises lap time,” says Lewis. Although this is already done to an extent, as seen with race-specific setups like those used to tackle the cobbles of Roubaix, he thinks that professional cycling could take things even further, and uses the example of an aerodynamic staple – the skinsuit.
“If you've got two skinsuits that in the wind tunnel straight ahead at 20mph have got the same drag, they're going to have different drags at different speeds and different drags at different yaws. If you map each suit on that rider on that bike over speed and yaw, you can quite quickly work out how many joules of energy each suit is going to take over the different courses. So although on the face of it, they look pretty similar, one will have more or less speed and yaw performance than the other.”
He adds that this is already happening thanks to apps like myWindsock – a Strava plug-in that helps riders plan what to wear pre-ride and analyse their CdA post-ride – but that, taken to the next level, it could help influence all aspects of a rider’s setup with a vast selection of aero-optimised clothing on hand that would each perform best under certain circumstances.
“If you take that to the extreme, you go in the wind tunnel and you start looking for a suit that performs with a windy day or slow day or fast day – for example, it’s day 16 at the Tour, there's the weather, there's the stage, that's suit 53.”
Creative exploiting
Aero tech tends to follow a regular pattern of being introduced only to be banned by the UCI, and Lewis believes this game of “cat and mouse” between teams, manufacturers and cycling’s governing body is only set to continue as designs push the limits.
“It doesn't matter how they change the rules, there will always be things to go and exploit and explore. We've seen a lot of development everywhere but helmets in particular are getting quite big and bold – I expect the UCI will pull those back in. Triathlon is doing some creative things with water bottles. People are doing things like looking at integrating the shoe and the pedal – maybe the UCI will ban it, maybe they won’t.”
It’s not limited to gear though, and he believes devices like the BodyRocket real-time aerodynamics analyser could be used to provide live feedback to a rider during a time trial, helping them to optimise their riding position.
“I could imagine that without too much effort you could have a feedback loop where the rider is moving their body position to minimise the drag and the code could be whispering in their ear ‘move your elbow forwards, rearwards, head up a bit, down a bit’.”
But if continuous glucose monitors or breathing sensor Tymewear are anything to go by, it’s likely that such a use would be banned during competition.
Quantum computing, rather than AI, will drive the next leap
The aerodynamics of cycling is very challenging. Unlike a Formula One car or a structure like a bridge, there’s not one fixed geometry, while the surfaces involved are constantly changing. “Things are moving but not consistently, skin is squashy, the bike shimmies, fabric changes with position and opens and closes as the leg moves, moisture affects the surface roughness,” he says. “It's why a bunch of CFD guys built a wind tunnel or two because we can't model it in CFD.”
While AI is touted as the future in a lot of industries, Lewis doesn’t think it will unlock any novel, untapped designs in cycling. “What AI can do for cycling is it can take five years worth of wind tunnel data, – images, movies and drag – and it can say ‘generally speaking, this works and that works’. But what works for one rider doesn't for another.”
Instead, he believes that there’s another technological innovation that “will shoot us off to the moon. “The game changer will be when we've got a quantum computer and can do a CFD calculation that would normally take three weeks in three seconds. We could then model things like turbulence and transition. But that one's quite a way off because they just take vast amounts of compute power.”
Rethinking riding formation
Tune in to a flat day’s racing with a crosswind and you’ll see the peloton strung out in an echelon formation – where the slipstream is shifted and drag offset from directly behind the rider in front to the side.
But Lewis believes that the idea of formations won’t just be limited to sidewinds, and could be refined regardless of conditions or parcours to be used as a tactic to better shield a team’s lead rider.
“When you run out of places to find gains, eventually you'll start to look at things like that,” he says. “It's something we haven't really done because we've got a wind tunnel that only fits one rider, but we can kind of do it in CFD and we've done it for running challenges where we've optimised a group of runners to minimise the drag on the key runner,” he says.
“It's not beyond the wit to think that if wind's coming from the east, I'm traveling north, I've got three riders, they probably don't want to be in a straight line. But whether they want to be on a diagonal, 20 degrees, overlapped or spaced is a problem that can be solved.”
