The numbers behind the breakaway that stunned the Giro peloton in Milan

They had never been granted a leash longer than three minutes, and with 66km to go, they were only two minutes ahead of the peloton. 

Normally, the sprinters’ teams would reel in the breakaway like a shark stalking wounded prey. But on this hot day in Milan, the breakaway had something else in store. GC gaps were neutralised on the city circuits, but the sprinters’ teams kept chasing in hopes of the stage win. 

With 10km to go, the gap was down to 45 seconds. How could the breakaway possibly survive? Surely they wouldn’t be able to make it. 

For the first 145km of the stage, the breakaway averaged 50.5 km/h, likely assisted by a tailwind at first, but then they forced the pace even higher around the Milan city circuits. 

Over the final 10 kilometres, the breakaway averaged 53 km/h, an unbelievable average speed that kept the peloton at bay. The sprinters could see the breakaway in the distance, but it was too little, too late. 

Dversnes Lavik sprinted to the win ahead of Maestri and Marcellusi, with Paul Magnier winning the field sprint for fifth. The result was calamity on one side, brilliance on the other. While the peloton had failed to chase down a seemingly harmless breakaway, the escapees had outfoxed the world’s top professionals. 

Their effort was judged to perfection, with just enough left in reserve to keep the sprinters at bay. So, how did they do it?

The key to winning from the early breakaway is baiting the peloton into granting you a winnable gap without using too much effort. We’ve seen countless breakaways earn a five, 10, or even 15-minute gap. 

But most of the time, they’ve burned too many matches to get that far out front. The breakaways that survive are the ones that earn a two to three-minute gap while riding at 90% of their capacity. Then, just as the peloton starts to accelerate, so does the breakaway. 

With 25km to go in Stage 15, the peloton tried to accelerate to chase down the breakaway. But the break was able to match that acceleration, keeping that gap around a minute until the finale. Then, with 10km to go, the peloton was in panic mode. 

They were riding as fast as they could, but the breakaway still had an acceleration left in store. A typical breakaway can average 45-50 km/h for an extended period of time, but on this stage, the break was able to hold 53 km/h for the final 10km. 

That is the kind of speed that is almost impossible to chase down. The peloton would’ve had to go 55-56 km/h in the finale, fast enough that teams would burn through their leadouts in a matter of minutes.

Here is what it looked like from the legs of Mirco Maestri:

Maestri - Final 10km of Stage 15

Time: 11:18
Average Power: 361w (4.8w/kg)
Max Power: 1347w (18w/kg)
Average Speed: 53 km/h
Max Speed: 66 km/h

The breakaway’s effort in the final 10km is surely impressive, but even more so when you put it into context of the entire stage. While the majority of the peloton was riding easy on the roads to Milan, the breakaway was pushing over 300w and 50 km/h for 145 kilometres. Maestri averaged 331w for the entire three-hour stage, burning over 3,600 kJs in the process. 

Maestri - Giro d’Italia Stage 15

Time: 3:03:29 
Distance: 155km 
Average Speed: 51.06 km/h 
TSS: 198 
Average Power: 331w (4.4w/kg)
KJs Burned: 3,646 

There are only a few stages remaining in this Giro d’Italia, and if a breakaway wants a chance to win, they need to follow this playbook. Things get complicated with climbs and changing wind directions, but we saw in Stage 15 how a break can outwit the peloton.