NICE, FranceTheir fingers were too numb to grip a water bottle, let alone the brakes. As the freezing rain turned to hail on a Saturday afternoon in March, the riders in the peloton shivered their way up the Col Saint-Roch. At the top, there was no relief. As hard as the ascent was, the worst part of the stage was ahead of them: They now had to plunge down the hill.
French rider Tony Gallopin of team Lotto-Soudal, who was chasing the leaders group in the Paris-Nice cycling race, knew the famously steep drop in the hills behind Nice would be hair-raising. But like a lot of modern riders, he had learned that seconds could be mined on these mountain descents.
Chasing world road race champion Michal Kwiatkowski, he tucked his body into the most aggressive aerodynamic position he knew. He moved his backside off the saddle and practically rested his chin on the handlebars, where he clung on for dear life.
On the slick, narrow roads, any debris, any jerky twist of the wheel, would cause his inch-wide tires to skid at more than 50 miles an hour. From there, he could be thrown into the side of a cliff, a guardrail or into sheer oblivion.
Mr. Gallopin pulled away when Mr. Kwiatkowski ran out of gas, and he eventually swooped down the final descent alone to win the stage. His body and bicycle had made it in one piece. His nerves, not so much.
I took a lot of chances, Mr. Gallopin said in French at the finish. And the brakes werent working at the beginning. I scared the daylights out of myself.
Not often discussed, riding downhill is cyclings supreme test of derring-do. Even seasoned pros avoid going downhill full tilt if they can help it. And as the Tour de France sets off Saturday with two-time Tour champion Alberto Contador of Spain, 2013 winner Chris Froome of Great Britain, 2014 winner Vincenzo Nibali of Italy and the 25-year-old hotshot Nairo Quintana of Colombia battling for the lead, the difference, cycling experts and riders say, may very well come on the way down.
Theres been a flurry in the last couple of years of guys like Nibali, who have seen that there are gains to be made in the descents, said Dave Brailsford, the architect of Team Skys victories in the 2012 and 2013 Tours.
Bicycle makers continue to produce lighter machines with better grip and more powerful brakes. Riders have been flirting with unheard of speeds during descents, touching 70 miles an hour. And race organizers have been responding with more challenging mountain stages than ever. The past four editions of the Tour all featured at least 11 downhill sections so steep that the road lost 50 meters in vertical elevation per kilometer. Ten of the descents in this summers race are even stiffer, averaging at least a 6% downhill, including the notoriously technical Col dAllos in the races final week.
In bike racing, there are 90% of the riders saying, That descent is too dangerous and we shouldnt be doing that, said Jonathan Vaughters, a former U.S. Postal Service and Crdit Agricole rider who now runs the Cannondale-Garmin team. And the other 10% are thinking, This is how Im going to win this race.
In the sports rampant doping years, all the focus was on the climbthe area where riders with enhanced blood could make up the most ground. But today, with doping believed to be far less prevalent, one of the biggest advantages seems to be a matter of guts. Descending barely requires pedaling, just seriously advanced bike handling. The only limit is the riders appetite for risk.
Sometimes youve got to do bad stuff to get down a hill quickly, said Cannondale-Garmin rider Alex Howes. Stuff your mom wouldnt watch you doing on TV.
This summers Tour marks two significant anniversaries in its tumultuous love affair with the mountains. It is the 40th birthday of the iconic red-polka-dot jersey, awarded to the Tours King of the Mountains. But it is also 20 summers since the death of Fabio Casartelli, who crashed on the descent of the Col de Portet-dAspet in the Pyrenees, a section of road that still appears on the Tour.
Mr. Casartelli isnt cyclings only victim of the downhill. More recently, the 2011 Giro dItalia claimed the life of Wouter Weylandt ; the 2009 Giro left Pedro Horrillo in a coma after he plummeted down a 200-foot ravine; and, in May, Domenico Pozzovivo had to quit the Giro after a gruesome crash while aggressively rounding a corner.
So when organizers hear fans demand more daring stages, more made-for-television drama, these considerations weigh on their minds.
I see sometimes on social networks, They dont dare try anything. Shouldnt we have a time-trial in a descent? Tour de France director Christian Prudhomme said, referring to stages when the riders go out one-by-one and race the clock. We would never do that. It would be irresponsible. Its insane. Yes, it could spice things up, but to what extent: killing people? It makes no sense.
Still, organizers test the boundaries. They know that mountains drive ratings. At the 2009 Giro, after Mr. Horrillos downhill crash, the peloton protested a course for being too dangerous. The boys in the bunch are livid, Lance Armstrong wrote on Twitter at the time. Two years later, also at the Giro, the peloton considered another protest after seeing the gravel-road descent off the infamous Monte Crostis. There is not just one or two but 10 men that could ride off the edge there, one racer said at the time.
Women cyclists are also squeezing seconds out of downhill stretches, although their top stage races, such as the Giro Rosa in Italy and Womens Tour of Britain, are much shorter.
Marianne Vos, the worlds top female cyclist, has worked closely with mountain bikers for years to hone her technique riding downhill, most recently at her teams January camp in Spain. It is no coincidence that Ms. Vos, also a multiple world champion in cyclocross, has used her speed in technical descents to build leads in all three of her womens Giro wins.
When youre actually looking at mountain stages in the Tour de France and doing reconnaissance of them, youre reconning the descents more than the climbs, Mr. Vaughters said. Because at the end of the day, the climbing, thats just a physical effort. A climb is a climb is a climb.
Each mountain crest brings a set of potentially life-or-death questions. Riders heart rates slow from around 200 beats a minute to under 100, but their focus cant drop. Vital downhill skills include precisely timed braking, efficient cornering and a mastery of aerodynamics.
How do you cut the corner? said Trek Factory Racings Fabian Cancellara, a veteran of nine Tours and one of the best downhill riders in the professional peloton. Do you brake? Not brake? How much do you trust the tires?
Some questions are less technical and more existential. They all affect how hard a rider is prepared to go, Mr. Cancellara said. Are you young? Are you a bit older? What are your goals? Do you have a family? Do you have kids?
It can take months to restore confidence after even a small crash downhill, Mr. Cancellara explained. Lars Boom, a Dutch rider for the Astana team, said he had to coach himself back to descending at full speed after his first daughter was born.
The problem is that descending is almost impossible to practice at top speed. It is too dangerous for teams to send their best riders hurtling down mountains with nothing at stake. Plus, they dont get roads to themselves in training the way they do on the closed course of a race.
You either have it or you dont have it, this skill, Mr. Cancellara said.
For those who do, technology is constantly giving them the tools to maneuver faster.
Carbon-fiber bike frames made the first impact when they began replacing steel and aluminum in the late-1990s, instantly making bikes lighter. The frames used by professional riders now weigh around 2 pounds, making them fasterbut also more finicky. At the same time, manufacturers have made advances in the development of rubber compounds for tires, improving grip at high speeds.
But the biggest jump has come in the brakes department. Improvements in the materials and precision of caliper brakestwo pads on each wheel squeezing the rim, a design used for a centuryhave given the riders the ability to carry huge speeds into bends.
The stopping power and modulation has improved a lot, even though its still just within the caliper-brake realm, said Cannondale-Garmin team leader Andrew Talansky.
Brakes are about to improve more with a major innovation: disc brakes. Commercially available on road bikes, they operate by giving the brake pads a cleaner surface to act on. Instead of pinching the rim of the wheelwhich also needs to be light, strong and aerodynamicthe brakes squeeze a disc at the wheels center.
The bike manufacturers lobby has been urging the sports governing body to approve disc brakes for use in the three Grand Tour competitionsthe Tour de France, Giro dItalia and the Vuelta a Espaafor years. In April, the Union Cycliste Internationale approved testing in races below the top-tier beginning this August, with a view to officially introducing them at the highest level in 2017.
Nowhere will they have a bigger impact than in descents. With more stopping power, riders will be able to carry more speed into corners and brake harder a fraction of a second later. The problem is, in a sport where one riders mistake can take out a whole pack, Mr. Cancellara said, You cant trust everybody.
Walking a tightrope
Cornering at high speeds is where cycling meets Formula One. The difference is that Formula One drivers know what the full corner looks like. Cyclists, most of the time, are whipping into the unknown. They look for clues in the final yards: loose gravel or slippery patches on the road surface; traffic signs advertising a chicane or a switchback. More valuable is the timing of the brake light on the police motorbike leading the pack.
(Tour veterans say the trustworthiness depends on the type of officer. Local cops? Theyre OK. But the motorcycle-mounted French Republican Guard, battle-hardened regulars of the Tour, are better.)
As they approach the corner, riders feather the brakesmostly the front to avoid skiddingand begin to scrub some speed. Touch here is so important that many riders keep their fingers exposed, even in frigid conditions, to feel every vibration as the brakes judder beneath them. Shifting their weight to the outside pedal, they lean the bike in to corner, tracing an efficient line across the apex. Locking the brakes here is asking to crash.
When you really do lay it all on the line and you have your flow, Mr. Talansky said, then it is like walking a tightrope, with that same mental engagement and focusYou can just feel that youre not making mistakes.
On the exit of the curve, riders begin to accelerate again and squirm back into the tuck. With their chests parallel to the ground, they absorb every bump in the road in the small of their back.
It boils down to technique, concentrationand cojones.
Take Janier Acevedo, a young Cannondale-Garmin rider from Colombia who is indiscriminately referred to as insane by his teammates. I like the descents when theyre wet and slippery, when its more difficult for everyone else, he said. He goes one step further than most on the straightaways, by taking his hands off the handlebars and gripping the stem below them. His face is practically stuck to the speedometer, which showed he once cleared 75 miles an hour.
Sin miedo, he said in Spanish. No fear.
Which makes him an exception. At the 2013 Tour, French rider Thibaut Pinot reached the summit of the Col de Pailhres near the top contenders in the overall competition. As a 23-year-old flag bearer for the FDJ outfit, this was his moment for a statement. All he had to do was keep up on the technical descent. The problem was he was petrified.
Due to a severe crash in a downhill as a junior, he told reporters later, Im scared of speed the way others have phobias for spiders and snakes.
By the end of the day, he was six minutes behind the overall leader, an eternity in cycling. He was still mentally shattered when he lost 25 more minutes the next day. It took him months to get over the performancehis team eventually hired a professional rally driver to race him around and re-educate him in matters of speed.
Riders can smell fear in the pelotonrivals braking at awkward times, or timidly taking cornersand it feeds competition.
There area lot of guys who cannot descend. Or maybe who think they can descend, but they cannot, said Mr. Boom, the Dutch rider, who credits his bike-handling skills to a background in cyclocross.
There are two kinds of descenders in the professional peloton. At the front, the Contadors, the Nibalis, the riders scratching out every last second in the general classificationthe competition to win the overall race. And at the back, the guys who couldnt climb out of a paper bag.
Usually, bigger than the flyweight Grand Tour contenders, they drop out of the main group by going too slowly uphill. At the top, the stragglers, known as the gruppetto, face a decision: shoot downhill to rejoin the peloton, or risk elimination by falling behind that days cutoff time.
A veteran usually organizes the gruppetto. He knows exactly how to calculate that days cutoff time and how to push the group home. But accidents are unavoidable in a crowd desperate to make time. Knowing how to crash properly is cruciallike keeping your head out of oncoming traffic.
You just watch it happen, Cannondale-Garmins Mr. Howes said. Here we go, I hope I find a good spot to land.Key stage
Sitting in his office on the outskirts of Paris, Mr. Prudhomme, the Tour de France director, began to list some of the potentially traumatic descents riders have to look forward to in the race he designed this year. They are stacked into the second and third weeks for the riders who survive the gales and cobblestones of the north.
He leapt over to a giant map of France on his wall and pointed to a spot in southeastern France: Stage 17, between Digne-les-Bains and Pra Loup, four days from the finish in Paris. The white-knuckle descent of the Col dAllos.
The climb itself is hard enough, 8.7 miles at an average gradient of 5.5%. But the other side of the mountain is the real strategic point, after 86 miles of racing. Snaking into the valley along a road the width of two Renaults, the riders will lose 3,400 feet in vertical elevation over the course of 10 miles.
All-time great Eddy Merckx flew down this descent in 1975 on his last ever day in the Tours yellow jersey. His swashbuckling bought him a minute over Frances Bernard Thvenet by the bottom of the valley. Mr. Thvenet, rattled by nearly missing a corner, called it The most nightmarish moment of the 75 Tour.
But the mental and physical strain had finally wasted Mr. Merckx. On the closing haul up to Pra Loup, Mr. Thvenet sailed past himand the Italian Felice Gimondi to win the stage on the way to taking the overall Tour.
Mr. Prudhomme expects it to be just as decisive 40 years later, a place for the big four to settle the overall classification for goodprovided they all make it there. Mr. Nibali, he said, is maybe not as brilliant a climber as Froome or Quintana. But he is a better descender. Great tactical sense, great intelligence. Id be surprised if he held back at Allos.
Several Tour contenders got a taste of it earlier in June during the Critrium du Dauphin, where one stage followed the same route. No one could keep up with French rider Romain Bardet, who called his solo attack off the Col dAllos suicidal. At the same time, he said after the full-gas descent, its rare to be alone in the lead. You let yourself go a little and you have to enjoy yourself.
Whichever rider takes advantage of it in late July, he will have heard the same advice every time he stops climbing and prepares to fly. You have to feel your way down the hill. You cant think your way down the hill, Mr. Howes said. As long as you dont touch the ground, its beautiful.
Write to Joshua Robinson at firstname.lastname@example.org