The Hunt for the Cobblestone Formula

GebioMized helps Trek-Segafredo find the best race set-up for the Tour of Flanders and Paris-Roubaix

Adapted from original version written by Felix Krakow


“Go! Go! Go!”

John Degenkolb has just launched an attack on the Kruisberg.  His acceleration on the climb generates a reaction from the favorites in the reduced bunch. The race is Dwars door Vlaanderen, the midweek classic ahead of De Ronde (Tour of Flanders), 43 kilometers remain until the finish, and at this point in a classic, only the strongest persist.

Ultimately, John will pay for his aggressive move and lose contact, but his attack further reduces the group and helps set up his teammates Jasper Stuvyen and Mads Pedersen, the latter who will go on to finish in fifth place.

John Degenkolb may still be finding his best form after illness set him back earlier this spring, but it’s not holding him back. He loves this time of year and his preparations and training for the cobbled classics have been extensive.

To speed over the cobblestones of the Northern Classics, John Degenkolb (“Dege”), together with the sports scientists of gebioMized, have put in a lot of effort and commitment into his race set-up.

It is with two critical races in mind that Trek-Segafredo puts in hours of testing with its partner gebioMized. Two one-day races that presumably every pro cyclist circles in red in the calendar: either to avoid the dreaded cobblestone passages or because they are the most important races of his season. The latter certainly is true for John Degenkolb. When the two cycling Monuments Tour of Flanders (April 1, 2018) and Paris-Roubaix (April 8, 2018) take place, Dege wants to ride at the front of the peloton. Right at the front!

Tour of Flanders and Roubaix are two of my season’s A-races. Therefore, all has to be perfect, and I do not want to leave anything to chance.

His mission: to shine on the dreaded cobblestones and to nab his next big win. In 2015, he was the first German rider to win the prominent cobblestone trophy in the Vélodrome de Roubaix since Josef Fischer won in 1896. “This was one of the moments I’ll never forget. Pure goosebumps. Indescribable,” John Degenkolb recounts. He longs for that feeling again. In 2016, a severe accident in training camp put him out of action. In 2017, he finished 10th.

Staccato over bumpy roads

John Degenkolb and Jasper Stuyven, again and again, catapult their race bikes over the merciless bumpy roads on a cold November day. It’s a time of year when most of their competitors are only easing back into training. It seems a lot of effort for the sake of science, but there’s a big goal: to determine which bike (Trek Madone or Domane) and what set-up is the most advantageous for the unique demands of Tour of Flanders and Paris-Roubaix. On board each bike: gebioMized technology for the mobile analysis of the set-up, especially at the saddle contact point.

“We are in search of the perfect cobblestone formula,” reveals Daniel Schade, the gebioMized sports scientist who sits in the accompanying car, his eyes spellbound on the monitor of his laptop. “We want to reach as much damping as possible on the cobblestone passages without paying for this by excessive power loss,” he adds.

Two races with completely different requirements

The preparation for the 2018 cobbled Monuments already began on April 10, 2017 – one day after the final sprint into the Roubaix velodrome. Then, the Trek-Segafredo athletes gave their first feedback on how their set-ups functioned during the race or how well their sitting position worked for them.  The entire team – from gebioMized and Trek-Segafredo to the Trek engineers – immediately started working with this information: What did we learn from this? What can be optimized? What adjustments can be made?

With the answers, the colleagues from the development department started working. They’ve got time, but only until autumn to implement the ideas. Then work in the laboratory starts. Each winter, John Degenkolb spends one full day in the concept lab of gebioMized in Münster to work on his set-up for the two prominent Monuments.

There may be lots of cobblestone passages in both races, but Flanders and Roubaix make very different demands.

The course between Paris and Roubaix is mostly flat, and the cyclists speed over cobblestone passages that are more reminiscent of a crater landscape than a road. The cobblestones in Flanders are almost silky soft in comparison, but the course has steep climbs. “Therefore, different sitting positions and set-ups can really make sense,” says Schade.

Measurable load for athlete and equipment

After the laboratory, it is time for a field test: the cobbled climbs of Flanders and the pavés of Northern France. It’s November, and the thermometer climbs to five degrees (Celsius), not more. For two days in the cutting cold, John Degenkolb and Jasper Stuyven speed over the key passages of these legendary races and put various options to the acid test. In the accompanying car, Schade’s notebook is centered on his lap: gebioMized’s saddle pressure measurement system transfers countless data to the computer – literally from the rider’s butt directly to the hard disc. In combination with the riders’ feedback, these objective measurement data allow for valuable conclusions as to whether the respective set-up really works.

Daniel Schade reveals two essential findings

  • In comparison to riding on the road, the athlete is shaken up 50 times more often on cobblestones. Every single cobblestone is an impact; a concussion in the system that reaches the saddle noticeably and measurably.
  • The rider’s center of gravity on the saddle is shaken up ten times more severely on cobblestones. The pelvis is continuously moving up and down, forwards and sideward. Therefore, the athlete has to spend more strength to stabilize the system actively. He’s literally dancing on the saddle.

The decisive power reserves

To get a perfect result, it does not suffice to trim everything to maximize comfort. As with so many things, it’s about finding a balance. “If we put too much emphasis on the dampening, the rider requires too much power to keep his speed up on the cobblestones,” explains Daniel Schade.

On the other hand, too little dampening leads to harsher concussions and nervous riding characteristics of the bike, and the rider has to put a lot of energy into stabilizing the system. And, of course, one rider’s set-up cannot be transferred easily to another rider: “There is a personal optimum between dampening and application of power for every athlete,” says Schade.

The brute effects of speeding over cobblestones are enhanced when muscles become increasingly tired during the race. And the sports scientist knows precisely what this means:

If you only save a few watts on Paterberg, or in the woods of Arenberg, thanks to the right set-up, that can be extremely important on the final kilometers leading to Oudenaare or Roubaix.

How much power will John Degenkolb and Jasper Stuyven save this Sunday over the 29 cobblestone sectors?

In the extensive hunt for the elaborate cobblestone formula, the true test – the merciless, jarring roads of the Hell of the North – will give the final answer.