Win behind Jumbo-Visma thanks to TU/e ​​and KU Leuven

The series of victories for Team Jumbo-Visma (TJV) during the last Tour de France is also to a greater or lesser extent the success of Eindhoven University of Technology (TU/e) and KU Leuven. Especially Bert Blocken, the Belgian professor of civil engineering at TU/e, and his team of wind tunnel specialists, deserve this honor. Research partners Surf (the ICT cooperative for Dutch education and research), Ansys (software), HPE Cray (supercomputer), AGU and Sportconfex (sportswear) also share in the success.

Coincidence or not, but since the Dutch cycling team has collaborated with Bert Blocken – from 2017 – the yellow-black riders have had wind in their sails. Blocken himself, as befits a good scientist, is modest about his role as a permanent adviser to the cycling team in the field of aerodynamics. He calls his wind tunnel project ‘one of the many puzzle pieces behind the cycling team’s success’. “If all these pieces fit right, it can lead to amazing results.”

In recent years, the professor has seen all the big stars from Jumbo-Visma come to Eindhoven to test in his wind tunnel. Tour winner Jonas Vingegaard, green jersey winner Wout van Aert, stage winner Christophe Laporte and frequent Vuelta winner Primoz Roglic improved their aerodynamics there, resulting in valuable time savings. The research led to a wide range of improvements. Don’t just think about the position on the bike, the ideal position in the group, the bikes and the clothes.

The head of the wind tunnel works closely with movement researcher Mathieu Heijboer, head of performance at TJV. Both performed numerous wind tunnel tests and computer simulations. Its results were the subject of in-depth scientific and technical discussions. This made it possible to determine the best position on the bike from an aerodynamic point of view. This did not just look at the results of the wind tunnel tests. Extensive computer modeling of the airflow around the riders also played a role. Not only the riders themselves are tested, but also life-size models of them.

Wind angles

Blocken explains that real cyclists always sit a little differently on their bikes in comparative tests. This affects the measurement results. You don’t know exactly what is causing the differences. Therefore, the researchers also work with a well-placed dummy with laser alignment. It’s always exactly the same.

The Equipment and Prototyping Center at TU/e ​​has also created a balance arrangement for the wind tunnel that the riders are placed in. This allows the researchers to have the riders pedal in any position with any force at any conceivable wind angle.

This year the Tour did not have a team time trial. Anders was also thoroughly tested in Eindhoven for the ideal sequence during such a time trial. Previous tests showed that a lot of time could be saved in the way the conductor of the train has to be relieved. If it goes upside down, it is important to bow wide. Before that, riders were used to falling right past their teammates. But it slows the others down.


During the wind tunnel tests, the researchers also noticed how much air pushes a group of riders forward. Those who drive in the front or in the middle will benefit greatly from this. From an aerodynamic point of view, it is smart to ride close to the rear wheel of another person at high speed. This applies on a flat road with no crosswind.

Each rider also pushes air aside. The models needed to calculate the influence of drag on riders in different formations are quite complex. In 2018, Brocken told NRC Handelsblad that a heavy computer should take two days to calculate the mutual impact. Therefore, the researchers are also happy with the computer time that NWO makes available on Surf. HPE also does this with input from its Cray supercomputer. Furthermore, Ansys, a supplier of software for creating simulation models, provides useful services.

Cycling Science

“Cycling science still has great potential for progress”

Blocken says on the TU/e ​​side that there is still great potential for progress in the field of cycling science. The end is not yet in sight for aerodynamics. “The complexity of aerodynamics, combined with the many variables in cycling, will provide decades of scientific innovation and significant time savings.”

The block makes computer simulations over a wide area. For example, he studies how trucks in a convoy can save the most energy by driving close to each other. He also managed to use computer simulations to determine the distance you can safely walk or cycle after an athlete with Covid-19. He was also able to quantify the advantage that escapees from the pack have when they are right behind an engine.

Tour de France Women

The Tour de France Femmes, which started on Sunday, also knows the computer scientists’ input. The Team DSM cycling team bases its tactics on a data platform made available by KPMG. The insights of this major bookkeeping and consulting club determine the number of riders who must be in the right place at the right time for a successful sprint.

Power data, video analysis, past results and the strength of other sprinters ahead form the basis of this sprint plan. The result was that sprinter Lorena Wiebes immediately took the first stage victory the day before yesterday. The sprint train analysis is part of KPMG’s data platform.

For example, the sprint is prepared on the basis of a ‘heat map’. This map shows the optimal number of riders in the sprint train in combination with the distance to the finish. This gives the team leaders the tools to make the right decisions. “They can tell the riders where to sit 5km, 2km and 1km from the finish,” said Paul Adriani, senior manager Digital at KPMG.

The insights that become available through this data platform should contribute to better team performance across a broad front. The analyzes and apps support, for example, the preparation of the season line-up, the development paths of the riders, nutrition, training and the tactical plan for a specific stage.

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