Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Become a Member

Get access to more than 30 brands, premium video, exclusive content, events, mapping, and more.

Already have an account? Sign In

Brands

Chris Carmichael Diary: Riding the slipstream to victory

Few events in cycling offer a team the opportunity to equally share in the pain and the triumph of a victory the way a team time trial does. Wednesday’s stage at the Tour de France required the complete effort of the U.S. Postal Service team, and the exhilaration of winning was clearly evident on the riders’ faces as they crossed the finish line. Lance Armstrong’s team showed today itself to be the strongest squad of the 21 teams in the race, and perhaps the most skilled as well. The team rode the length of the 64.5-kilometer course in nearly-perfect formation, close together, taking full

Don't miss a moment from Paris-Roubaix and Unbound Gravel, to the Giro d’Italia, Tour de France, Vuelta a España, and everything in between when you join Outside+.

By Chris Carmichael, Carmichael Training Systems

Chris Carmichael Diary: Riding the slipstream to victory

Chris Carmichael Diary: Riding the slipstream to victory

Photo:

Few events in cycling offer a team the opportunity to equally share in the pain and the triumph of a victory the way a team time trial does.

Wednesday’s stage at the Tour de France required the complete effort of the U.S. Postal Service team, and the exhilaration of winning was clearly evident on the riders’ faces as they crossed the finish line.

Lance Armstrong’s team showed today itself to be the strongest squad of the 21 teams in the race, and perhaps the most skilled as well. The team rode the length of the 64.5-kilometer course in nearly-perfect formation, close together, taking full advantage of the draft, and maintaining a smooth and steady pace. Horsepower may be the most important factor to winning a team time trial, but technique takes a close second.

During a team time trial, the pace is so high and your efforts on the front are so difficult that drafting becomes absolutely critical. In a study of U.S. National Team Pursuit riders, Jeff Broker and his associates showed the second rider of the four-man team had to produce about 71 percent of the power the leader was producing. The third and fourth riders had to produce about 64 percent of the leader’s power. This is still a lot more power than a rider has to produce when drafting in the middle of a large peloton, but it’s enough of a reduction to give a rider some recovery before having to pull at the front again.

The amount of power you have to produce while riding behind a single rider, or in a line of riders, changes based on several factors. Generally speaking, the closer you ride to the person in front of you, the more you can take advantage of his slipstream, which reduces the power you have to produce to stay at your current speed. Ideally, you want your front wheel within six inches behind the rear wheel ahead of you. Riding to within 12 inches is still good, but riding more than 12 inches behind another rider significantly increases the power you have to produce as the result of the diminished effectiveness of your drafting technique.

Of course, it’s also important to put yourself in the best overall position behind the rider ahead of you. In the work done prior to the 1996 Olympics it was clear that on the velodrome there was a significant cost, in terms of aerodynamic drag and power output, to riders swinging slightly left and right of the wheel ahead of them. Riding a smooth line directly behind the wheel was best. In the less-controlled environment of road riding, the best place to be changes based on where the wind is coming from, but it is still true that riding anywhere expect the optimal position increases the amount of work you have to do.

In the real world of road racing and team time trials, the science of drafting has to balanced with pragmatism. In rainy conditions like today’s time trial, there were times when the optimal position for drafting increased riders’ risks of crashing because of poor visibility, slick road paint, or treacherous corners. In the end, the fastest way to get from the start to the finish of Stage 4 was to blend science with the determination and skill of a very strong team.