Former Team Sky aerodynamicist on Giro's whacky TT helmet: 'It’s a great design and makes complete sense'

To say that Visma-Lease a Bike’s new Giro time trial helmet created a sensation on Monday would be something of an understatement. The radical new design, with its bulbous shape and enormous visor, made everyone do a double take at the unveiling on stage 1 of Tirreno-Adriatico – even some of us in the GCN office were genuinely left pondering whether the photos had been doctored in one way or another.

Social media was awash with ‘hot-takes’, Chris Boardman weighed in, and, needless to say, Jonas Vingegaard’s new piece of kit overshadowed the racing somewhat.

Read more: Visma-Lease a Bike debut spectacular new time trial helmet

However, away from the memes and the amusement, several key questions sprung up. The most obvious ones were why and who signed this off, so we spoke to one of the most well-respected specialists on the topic to get the real answers.

These days Robby Ketchell runs Aero.chat but he was the lead aerodynamicist at Slipstream Sports in the mid-2000s, before becoming Team Sky’s data scientist during the team’s most successful years. He helped the British team to three Tour de France titles, was also part of the Ineos 1:59 marathon Challenge, and has worked across several other sports, including the NFL and the NBA. To cut to the chase, he knows his way around a wind tunnel like no one else, and aerodynamics is his forte.

Like most of us who saw the helmet for the first time on Monday, Ketchell flicked through the hundreds of memes and social media comments that blew up after Visma-Lease a Bike’s TT recon and eventual race effort. However, unlike the majority of the comments that seemed to scoff at the design, Ketchell saw real merit in Giro’s efforts and praised one major element of the new helmet design.

“To be honest, it’s a great design and makes complete sense,” Ketchell told GCN from his lab in New Hampshire.

“The thing I’ve always said since I started to work in wind tunnels in 2008 is that the number one thing to make yourself faster is to close that gap between your helmet and your hands. That’s why the Floyd Landis and the Levi Leipheimer positions really worked back in the day because they were closing their hands by bringing their hands up.”

A new approach

Vimsa-Lease a Bike, however, have taken a slightly different approach. Instead of a more aggressive ‘praying mantis’ position that Landis used in the mid-2000s, the Dutch team relaxed the angle of the bars and instead brought the helmet and the rider closer to the hands.

“Jumbo are doing the opposite to close that gap, by bringing the helmet down. You’re basically creating a big windshield there that closes the entire section at the front and makes it a nice airfoil in front of the rider," Ketchell told GCN.

"It’s an optimal aero shape because you can’t create an optimal aero shape with your fists. They’re creating one with the helmet, though. It makes total sense. And even when you put your head up, you’re still having an improved shape, even if the gap isn’t closed."

© Getty Images

Attila Valter sporting the new helmet on Monday

It’s not just the hands-to-helmet factor that’s important. Other aerodynamicists have commented on the sleek nature of the tucked position that helps airflow over the riders' helmet and their shoulders. Ketchell acknowledged this but again stressed that it’s not the most critical point.

“100 per cent that view is right but the shoulders are less important than closing the distance between your head and your hands,” he added

“Weight also matters, definitely. That does count, along with the extra torque created on your neck, but also if you think about it, if they get down in the right position then they’ll put the helmet right down into their arms, and let it rest there.

"Back when Dave Zabriskie used to do his famous head-down position, his head was in his hands. So it might create a more relaxed position for them. Weight only matters if you’re going uphill or you’re creating more fatigue on the body but the only thing I don’t know is what the helmet is like in an impact.”

Read more: Another radical TT helmet – Bahrain Victorious debut unreleased Rudy Project ‘Wingdream’

One second per kilometre

You might rightfully ask why scientists and experts haven’t created the all-purpose cycling helmet that solves all aerodynamic conundrums in one fell swoop. The simple answer is that not all riders have the same body shape or riding position, and Ketchell adds that the gains, or rather the savings, in terms of seconds for each rider will differ depending on their position.

He also believes that the new-look helmet will have been tested and developed with the key time trials at the biggest races in the world in mind. For example, there are two time trials at the Giro d’Italia this year and two critical tests against the clock in this year’s Tour de France.

© Sirotti Stefano

The helmet as viewed from the side

“The savings are going to be larger for some more than others. If you look at riders like Jonas Vingegaard, they’re going to have larger savings because they have larger upper arms, so the distance between their forearms and their head is larger,” he said.

“So they have a less optimal position than someone who has shorter upper arms and who might already have their hands closer to their head. A rider like Magnus Sheffield is already almost optimal, his face already almost touches his forearms, so he’s not going to get the same amount of benefit from this helmet as Jonas would. The savings are even larger for a rider like Jonas. It could give a second per kilometre in a time trial."

Bigger is not always better

A key question going forward is whether we’ll continue to see helmets develop in this way over the coming months and years. Larger styles of this nature are not new, but the latest incarnation from Giro certainly pushes the boundaries of what’s been seen in the past from the likes of Specialized and POC.

According to Ketchell, it’s not just a matter of size, but rather how the design works in conjunction with the rider, and the TT set-up.

“It always happens this way, and then the rules change and you need to modify the designs,” he said.

© X / Visma-Lease a Bike

This is a helmet of huge proportions

“I don’t necessarily think that a bigger helmet is always going to be better but the way in which they made the helmet bigger has really worked here. They put the extra helmet in the right place.

"A lot of people forget that the shape of the frontal area is more important than the coefficient drag from the rest of the body. And it also depends on the speed you’re going so I’m sure that this helmet has been optimised for the courses this year,” he added.

“I’m curious to see how it behaves in crosswinds, and how much you give away when you’re climbing and not in the optimal tuck but these are all things they would have considered. I’m curious if the rules will hold up for the rest of the year."