The aero road bike has become de rigueur in the modern peloton.
Lapierre developed its Aircode in response to demands from Marc Madiot’s FDJ.fr squad, which two or three times each year decamps to the Magny-Cours circuit, once host to the French Grand Prix, when such a thing existed, and to the wind tunnels of Aero Concept Engineering (ACE), there to hone positions and to test a range of equipment, including helmets and clothing. And bikes.
Nearly all of the manufacturers with ProTeam clientele have such a machine in their range. The sculpted tube profiles are intended to cheat the wind, and while there is no shortage of data illustrating watts and seconds saved, it’s important not to overlook the significance of the rider, whose bulk accounts for the overwhelming majority of aerodynamic resistance, or that wind is far from the only source of drag encountered by a cyclist.
Rémi Gribaudo is chief designer for Lapierre Cycles, and the man entrusted with the design and development of all the machines ridden by FDJ.fr, including the lightweight Xelius climbing bike and the Aerostorm time trial machine. To develop the Aircode – a chassis which passed through four iterations, and whose development relied heavily upon real world testing of physical prototypes, rather than time consuming CFD profiling – he called upon French champion Arnaud Démare, and William Bonnet, Yoann Offredo, and Arthur Vichot.
Note the preponderance of sprinters and 1s in Gribaudo’s focus group. An aero road bike is likely to be of most benefit on flat roads, where aerodynamic drag represents a greater obstacle than gravity. For the fast men, fractions of a second saved in the race for the line are all-important, and for those likely to spend hours beyond the shelter of the peloton, racing alone or in small groups, the advantages are similarly obvious.
That said, the Aircode has been almost universally adopted by FDJ.fr’s riders, including its GC leader, Thibaut Pinot, who provided the machine with valuable exposure en route to a podium finish at last year’s Tour de France. So is the aero bike always superior? Gribaudo chuckles. “It’s also due to the fact that it’s the newest one, and the riders always like to ride the newest bike,” he says, laughing. More seriously, he highlights that the Xelius is equally stiff in its lay-up, both in production configurations and the custom options tailored for FDJ.fr’s sprinters.
The production machine is woven from a range of fibres. The stiffest 40-tonne thread is used for what Gribaudo refers to as the “power zone” – the downtube, headtube, bottom bracket, and the section of the chainstays adjacent to it. Elsewhere, a 30-tonne, medium modulus fibre is used, and in areas where flex is required, rather than occurring as an unintended response to rider input, Lapierre has deployed Toray 700; a 24-tonne fibre. FDJ.fr’s sprinters, however, enjoy the luxury of custom lay-ups, Gribaudo reveals, both in the Aircode and the Xelius, such is the additional power they are likely to produce.
The Aircode is not the first aerodynamic machine that Gribaudo has designed for FDJ.fr. In 2013, he developed a new iteration of Lapierre’s Aerostorm, despatched to the Tour squad for the team time trial in Nice. The challenge of designing an aero road bike within UCI regulations is less than meeting the same requirements with a time trial bike, he says; indeed, the design philosophy and working method used to create the Aerostorm were used for the Aircode.
For example, Gribaudo used CFD calculations to determine the aerodynamic “weight” of various configurations, to gain what might be described as a close-up view of the advantages of, say, changing a conventional round tube to a flat-backed, Kamm tail profile, or moving the brake position.
The Aircode is little more than a year old and has gained just one significant revision: the abandonment of a chainstay-mounted rear brake in favour of a more conventional mounting on the seat-stay. A number of reasons lie behind the change, Gribaudo says, but chief among them is ease of maintenance.
With significant changes to UCI regulation imminent, might the Aircode be subject to further revision? Gribaudo understands that the UCI will allow machines with disc brakes to be tested in two races this year, before further testing next season, with a view to legalising the technology in 2017. Lapierre already has a disc-equipped machine – the Sensium “endurance” bike – which has been tested by FDJ.fr riders. Lapierre would weigh the impact on aerodynamics before deciding whether to make a disc-equipped iteration of the Aircode, Gribaudo says. “If we see that the disc is against the aero element, probably we would not chose to make the Aircode the disc brake model.”
The machine pictured is the Aircode Ultimate Red, from the French firm’s top-tier. The Ultimate programme offers a choice of paint scheme (FDJ.fr colours are the alternative), contact points and wheels. This bike has been configured with Mavic Cosmic Ultimate hoops, 3T’s Ultimate Stylus finishing kit, a Selle Italia SLR Carbonio saddle. The components are from Shimano’s top-tier mechanical groupset, Dura-Ace 9000, and the Di2 equivalent is offered too, as well as mechanical and electronic options from the second-tier Ultegra group.