And so Blocken started to compile data, looking at other well-known descenders and their styles, creating simulations to test the speeds and rates that each would descend. He wasn’t sure what he would find, but he was intrigued. “In this type of study, we often find results that are unexpected, even for ourselves,” he says. “Aerodynamics is very difficult to gauge by intuition. Many people thought the Froome aerotuck was aerodynamically superior, because he won the stage. But science shows otherwise.”In fact, the results of his research showed that the “Froome position” was inferior to several other positions. “The Froome position is not faster, not safer and not more powerful compared to other positions,” the study notes. “Other positions are up to eight per cent faster, provide more equal distribution of body weight over both wheels, and allow more power generation.”That’s a tough pill for Froome to swallow, and also leaves the question open of what position does work the best.”The best position will be a combination of several positions,” Blocken says. “When descending without pedaling, a position on the top tube sitting against the saddle and with the back stretched as much as possible is much faster than what Froome did. It is also safer, because the cyclist body weight is more equally distributed over both wheels. Peter Sagan uses this better position quite often. When pedaling is needed, one might choose to alternate between a position on the top tube and one on the saddle, where the head is as close as possible to the handlebar.”
Sagan can handle that, but for the average Joe (or Jill), Blocken says, it ultimately doesn’t matter what’s faster, it’s about what’s safest and most comfortable. “I think every cycling fan still remembers the tragedies of lost life of Fabio Casartelli, Wouter Weylandt and Antoine Demoitié and others,” he says. “Cycling is already dangerous enough as it is. The recreational cyclist has not reason to try dangerous tricks.”
So remember this: the next time your group ride speeds up on a descent, you can internally giggle at the guy in the aerotuck if you want to—just be sure to distribute your weight evenly, and stay safe.