The Power of The Koppenberg: Watt It Takes to Race Belgian CX

From the village of Melden, Belgium, the cobbled stones of the Steengat road climb above the rolling Flemsish countryside. Though it gains only 77 meters in total height, this stretch of pavé is among cycling’s most feared and fabled stretches of road. The slopes of the Koppenberg are the stuff of legend–each the spring, it is a staple climb in the Tour of Flanders, and each fall the cobbles again take center stage as the best cyclocross racers in the world climb the brutal incline over and over again during Koppenbergcross. Tens of thousands of fans climb the grassy cow pastures alongside the road to watch riders wrestle up the slopes, which top out at 22 percent. Peloton sponsored rider, Andrew Juiliano lined up at the bottom of the Koppenberg this year, and managed to capture the race with his power meter. We’ve enlisted the help of his coach, Hunter Allen–author of Training and Racing with a Power Meter and the founder of Peaks Coaching Group–to analyze Andrew’s file and see just what it takes to tackle the Koppenberg over and over again.

Words: Hunter Allen /Photos by Balint Hamvas

Koppenbergcross is distinctive, even by Belgian cyclocross standards. There are no sand pits. No barriers. No dismounts whatsoever (unless it’s raining, and the cobbles turn into slimy, slippery bricks). This course is purely about smashing uphill, keeping pace as the tape winds through the bumpy cow pasture up top, then holding on for dear life through the chicanes and high-speed descent back to the bottom. Do that over and over again for an hour, and you have yourself Koppenbergcross.

The start of the race is truly unique.  Whereas most starts have a 20 to 30-second sprint, Koppenbergcross commands a 90-second effort straight up the cobles before turning into the field. During this time, Andrew put out a one-minute power of 660 watts (Figure 1). The effort moved him from the second to last row up to 17th place. While that kind of effort makes most people’s eyeballs want to bleed, this sort of start suits Andrew quite well–the effort was still about 15 percent lower than his maximum one-minute power in controlled tests. Of course, the start of a cyclocross race is far from controlled–it was chaos as he bounced up the cobbles, dodging wheels and weaving through the field.

The unrelenting pace of Belgian cyclocross also defines the racing. If you are not attacking, you are moving backward. Up until the descent on the first lap, Andrew put out a 5-minute normalized power of 464 watts. The normalized first ten-minutes of the race were 421 watts. Despite these efforts, Andrew still faded back 8 places to the mid 20s. Can you imagine going backward while pushing nearly 6 watts per kilo for 10 minutes? Belgian racing is truly next level.

There is more to a ‘cross race than one lap or a big effort–the discipline requires the ability to dig deep over and over again for an entire hour or more. This is what is known as FRC or Functional Reserve Capacity. FRC includes all efforts that fall into the categories of Neuromuscular Power, Anaerobic Capacity and Vo2Max training levels. Andrew has exceptional FRC, and it is considered world class at 26.6 kiloJoules. In order to expend it all in one shot, he would do 2,660 watts in 10 seconds.  Instead of blowing it all in one effort–if he could, he should quit his CX day job and become a superhuman road sprinter–Andrew distributes this work over the course of the race. The ability to repeatedly go above his FTP allows him to race cross at the highest level.

We see this FRC at work as we analyze his multiple efforts up the Koppenberg (Figure 2). The full climb went from the bottom of the cow pasture and spent about 75 to 80 seconds climbing through the grass. A short, technical off camber spit onto the steepest part of the Koppenberg. During the opening ascent, which went from the very bottom of the climb, Andrew had to smash straight up the bumps due to the chaos of the starting scrum. On subsequent laps, a narrow curb hugged the left-side dirt embankment, allowing for a smoother though more delicate, line up the steep section. Andrew was able to pace these efforts, and he actually improved his power and time up the cobbled section of the climb each lap. On the the full two-plus minute climb, he averaged about 410 normalized watts, while the steep section demanded an average power of 440+ watts each time. The efforts certainly took their toll though. After the descent, he started each climb with his heart rate around 170, though over the two-minute effort, it would reach the high 190s and top 200 on several occasions.

Though he finished a lap down, Andrew still managed a full hour of racing. His normalized power for that time was 352 watts, which is 4.9 watts per kilogram for an hour of racing. The effort got him his best ever result in the brutal theater of Belgian cross, 25th, on the day, and several trips up on of the most iconic cobbled stretches in all of cycling.