Tailoring the Wind: Shaving off the seconds with Rapha’s new skinsuit Cycling sportswear brand Rapha aims for success in the Tour de France with its latest gear

When Rapha, the British cycling sportswear brand, started working with Team Sky in 2013 there was a vital part of the cyclist’s wardrobe it didn’t offer. The skinsuit – the tight-fitting bodysuit worn during the time trial, where cyclists race against the clock on specially designed aerodynamic bikes – is a new development in the sport and is proven to save crucial seconds and even minutes. Although Rapha supplied Sky with the shorts and jerseys that were worn to victory by Chris Froome in 2013 and 2015 in the Tour de France – the most prestigious and demanding race of the sport’s calendar – the skinsuits were supplied by a different manufacturer.

However, for the time trials in the 2016 edition, Team Sky could finally ride in Rapha’s own design. Over six months, 21 prototypes using a combination of 23 different fabrics were tested in the wind tunnel and on the track to produce what Rapha believes is the fastest skinsuit available, a process involving a collaboration between Team Sky, Rapha and scientists specialising in textiles and aerodynamics.

Team Sky Rapha Development

The finished skinsuit is designed to help riders slip through the air with the least amount of drag. Four fabrics have been arranged in 13 different panels and strategically stitched together to minimise wind resistance, reduce turbulence and tailor the way the wind flows over the rider’s body. Innovatively, the suit compresses the shoulders, helping the rider maintain the extreme, low-profile aerodynamic position on the bike. When compared to Sky’s previous skinsuit, Rapha claims this new design saves 15 seconds over a 30-minute time trial, a considerable improvement that could mean the difference between winning and losing the Tour.

Ahead of the 18th stage, where the riders faced a challenging 17km uphill time trial in the Alps, Avaunt spoke to Rapha’s head of product development, Simon Huntsman, to gain an insight into the long and complex process of developing the fastest skinsuit available.

In the time trial riders have to maintain an extreme position
In the time trial riders have to maintain an extreme position on the specially designed bikes to minimise aerodynamic drag

Why is it only now that Rapha, which was founded in 2004, are launching their own skinsuit?

We felt there were a lot of other opportunities within the professional arena that were a bigger priority, where we could make bigger improvements and continue to develop kit that can be used more frequently, like the Aerosuit [a skinsuit designed for normal racing with pockets in the back] which we launched last year.

But, as it is our last year working with Team Sky, we felt the skinsuit was the final piece of the puzzle that we really needed to get right. It was an idea that really resonated with Team Sky because the Bioracer suit that they previously wore for time trials was used by many different professional cycling teams, and they are always interested in doing something different to gain an advantage.

Team Sky and experts on aerodynamics
Alongside Team Sky and experts on aerodynamics, Rapha tested 21 prototype suits in the wind tunnel and on the track

How important was it to work with Team Sky?

It was vital to have the involvement of Team Sky and their innovation team, but that happened quite far down the line when we had the opportunity to test the suit with Geraint Thomas and Chris Froome. We used an independent consultant as part of the development of the suit and then we had Simon Jones, the head of innovation at Team Sky, working very closely with us to check our test methodology and our thinking – it was very much a partnership.

Could you run through the process of developing the skinsuit?

The first stage of the process was the initial fabric consultation and we started out in the wind tunnel, testing 17 different fabrics on their own before working up to 37 different combinations. We also tested the fabrics at different speeds, looking at how they performed between 20 and 70kph, because many fabrics have different drag coefficients at different speeds.

We used this data to help us select fabrics with the mean speed of roughly 50kph in testing sessions at Loughborough University, working with one of the lead professors of aerodynamics there. Once we selected our fabrics we started to apply aerodynamic theory and what we learnt from the wind tunnel to the garment’s design, all the while comparing our suit with existing skinsuits.

Then we built on our existing technology to look at seam placement, specifically mapping across our fabric knowledge from our wind tunnel tests to make 21 different prototypes that experimented with changing specific aspects and concentrating on different parts of the body to explore how we could affect the air movement across the body – in the legs, the upper body and then working on the high pressure areas, where the air hits first, like the shoulders or the front of the arm.

Rapha tested 17 different fabrics in 37 different combinations
Rapha tested 17 different fabrics in 37 different combinations when developing their skinsuit

How exactly is the skinsuit composed?

The suit itself is built up of four different fabrics. The fabric on the legs is a smooth fine gauge compressive knit structure which is required to support the muscles. On the front of the torso, the front of the arms and the sleeve we’re using a very high gauge knit structure which is very smooth for laminar flow. Then there are three different sections of mesh – if you look at the side profile of the suit there are strategically positioned mesh sections which are specifically designed to reduce air separation around the arms, on the side of the torso and across the back.

There’s a fourth fabric which runs down the upper body and the back which is a very light, super-smooth 60 gauge knit that helps to cool the rider while also having very good aerodynamic properties. So these four fabrics work together to do different things, whether it’s compression, controlling the movement of air or keeping the rider cool. It is also important to note how the suit was cut – it’s very tight across the shoulders which helps the riders maintain a position on the bike with the smallest frontal area and was also critical in making incremental gains in the aerodynamics of the suit.

Tailoring the Wind in a Rapha skinsuit

Generally we’ve seen a much more scientific approach to cycling in recent years, especially with regards to aerodynamics. Is this something Rapha will continue to develop?

Aerodynamics is not going to go away and whether you’re a keen amateur or professional athlete you want to improve your performance, so there’s definitely a mood in the market for faster, lighter kit. We’ve learnt a lot in this process and so what you’ll see from Rapha in the future is some of the interesting things we’ve learnt from this being implemented in a commercial product.

Words: George Upton

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