How breakaways keep holding off the sprinters
Some new factors are in play, including aerodynamic trickery.
Some new factors are in play, including aerodynamic trickery.
It happened again on Thursday. The break, just four riders, held off a charging peloton to deny the sprinters their very last opportunity at this Giro d’Italia. You could see the frustration written all over the fast men’s faces.
This is no new phenomenon but seems to be happening with increasing frequency. Breaks are being given smaller gaps, too. So what’s going on? How are they doing it?
There are a huge number of factors that go into a successful (or unsuccessful) breakaway. The biggest will always be group cohesion. On Thursday, winner Dries de Bont said as much. “I think it was a collaboration until the last [kilometer], but we didn’t speculate,” he said. They kept their heads down and went for it, no games.
The number of sprinters left in the race can be a factor, as can the motivation of various teams. Wind, rain, crashes and corners all play a role. But these things have always been there. What’s changed?
Ronan Mc Laughlin, our in-house marginal gains nerd (he’s also pretty good at breakaways) and I have been discussing this all week. Maybe you heard us on the CyclingTips Podcast. We had some theories. We talked to some folks who would know. Here’s what we came up with.
This one is a bit counterintuitive, but it’s key. Mostly gone are the days when a breakaway would be given ten or more minutes, left to dangle for most of the stage in nihilistic pursuit of TV time and little more. Those days lacked urgency, and that was the whole point.
Cycling has changed. Teams are smaller (one rider smaller at grand tours) and that leads to increased trepidation on the part of sprinter’s teams. They don’t want to have to chase back ten minutes because they don’t have as many riders. They need to save as many as they can for the leadout later on. So they keep it close.
The breakaways found in this Giro’s flat and rolling stages were rarely given more than three or four minutes. That’s a gap that’s seen as manageable by the sprinter’s teams.
Of course, sometimes it’s not. That smaller gap can lull the peloton into a false sense of security as the finale approaches. This can be compounded by our next factor.
This particular Giro d’Italia has seen a number of sprint stages with decent-sized climbs placed somewhere far from the finish line. They seem largely innocuous on paper. Perhaps an opportunity to get rid of Mark Cavendish or Caleb Ewan, which is what happened on stage five, but hardly a boon for the breakaway.
These small climbs become relevant when they fall slightly later in the stage, at a point at which the peloton is attempting to maintain its gap to the break, or even reel it in.
The problem for the sprint teams is they have sprinters. Sprinters don’t climb well. Climbs limit the speed of the chasing peloton to that of its slowest climbers, the sprinters, while a breakaway group can push on as hard as it wants.
An excellent example of this dynamic at work came on stage 13 from Sanremo to Cuneo. Spoiler alert, the sprinters actually succeeded here, Arnaud Demare won, but it was touch-and-go. The break was caught with less than a kilometer to go.
A breakaway formed in the first 15 kilometers of that stage, containing Julius van den Berg, Mirco Maestri, Pascal Eenkhoorn, and Nicolas Prodhomme. Four solid rouleurs. They pulled out 3:30 quickly, allowed to do so by the sprint teams. They were then kept around 3:30 until the day’s main climb, the category three Colle di Nava, which topped out 100 kilometers from the finish.
The break pushed on. Behind, the sprinters climbed as best they could, but the gap grew. Sprint teams could chase no harder without risking losing their sprinter. By the top, the break had nearly seven minutes.
This chart of the break’s time gap, from ProCyclingStats, looks an awful lot like the stage profile, doesn’t it?
What this all comes down to is breakaway riders utilizing course features to their advantage in ways that haven’t always been part of the game. It’s a sort of increased professionalism of the breakaway rider that has been years in the making. They know when to push, when to sit, and how to play the peloton against itself. They pick moments where they are guaranteed to take time on sprinters, like that category three climb, and use them.
The extra seconds they grab using these tactics are compounded by our last factor.
Maybe you’ve seen the stats on this year’s classics season already. In case you haven’t, it was one of the fastest ever. Dylan van Baarle’s Roubaix win was the fastest ever at 45.7 kph. Records were set all over the place.
A lot of that comes down to aerodynamic improvements across the sport. Helmets, clothing, wheels, frames – it’s all faster than ever.
Breakaway specialists are now as tuned into these developments are time trialists are. Taco van der Hoorn’s Giro stage win last year is a perfect example.
Van der Hoorn was off the front for 186 kilometers and won by four seconds. He rides hyper-narrow bars, wears a skinsuit, an aero road helmet, deep wheels – the lot. He is notoriously fastidious about his setup and removes every gram of drag he possibly can.
Why is this relevant for breakaways? Because the power needed to overcome aerodynamic drag does not increase linearly with speed. The watts required increase as a cube of velocity.
In short, the faster the break goes, the more difficult it is for the peloton to catch them. OK, this is obvious. But the math behind it is what’s relevant here.
For decades, the common wisdom has been that a raging, chasing peloton can pull back roughly 10 seconds per kilometer on a small-to-medium-sized breakaway. It was a Paul Sherwen truism every July. This is the math (roughly) that directors in team cars have always used to make sure the break gets pulled back in time.
That basic calculation breaks down when the breakaway up front manages to go even a few kilometers per hour faster than they used to. This can be due to a tailwind, a long downhill, superior group cohesion, or better aerodynamics. Aerodynamics is the new(ish) factor.
Breakaway riders are putting out the same watts as always, but all the aero trickery has them going a few kilometers per hour faster.
To pull back 10 seconds per kilometer the peloton has to go faster too. Maybe 52 instead of 50 kph. In terms of watts, the poor sap on the front of the peloton now has to push 510 watts instead of 460. That’s a lot. (Calcs assuming a 70kg rider in the drops with no significant wind or gradient.)
At some point, you run up against the limits of human ability. All because the breakway riders are still doing 450 watts, but now their CdA (drag) has dropped from .35 to .3, so they’re going 2 kph faster.
The 10-second rule breaks down. Maybe it’s 7 seconds per kilometer now now, or 5. That’s just enough for the break, which already took sneaky seconds all over the route.
Marginal gains guru Josh Poertner has seen this play out with the teams he works with. “I’d also argue that all of the efficiency and aero gains are what is allowing for ever longer breakaways to work,” he said. “I’ve done lots of math on this for various teams and the only antidote to it is increasing the aero performance of the entire peloton, or at least convincing/forcing every rider to ride the most aero bike possible.”
Breakaways have always survived on occasion. Such moments make for some of the most thrilling finales in pro cycling. But the game is changing, or has changed. There’s more to it now – more planning, more care in execution. Less drag, more speed. The biggest factor will always be breakaway group cohesion, but it certainly helps that the peloton hasn’t yet fully caught up with those riders on the cutting edge of the art and science of escapes.