Designing a Secret Weapon

By Tom Steinert-Threlkeld  |  Posted 2004-07-08 Print this article Print

Designing a Secret Weapon

This is where the 5,000-ride database of the Trek Bicycle Corp. comes into play. Using a combination of three-dimensional modeling software from Alias, once a unit of hardware maker Silicon Graphics; mechanical design software from SolidWorks; and low-cost, high-performance personal computers running Opteron processors from Advanced Micro Devices, senior industrial designer Michael Sagan and a project team of 12 worked from December 2002 to April 2003 to simultaneously design bikes that would give Armstrong an edge in two consecutive Tours. The first, which became the basis of Treks Madone line of bikes, was Armstrongs "daily drive" in the race pack, a.k.a. peloton. A second is to be his secret weapon in this years Tour, a version of the Madone called the SSL that is specially designed to race uphill.

The reason: The key stage in the 2004 Tour de France is likely to occur on July 21. Thats when each racer will face cyclings "race of truth," an individual time trial. Each rider departs two minutes apart and races against the clock, without the protection or aid of any teammates. And this year, the key time trial is not on flat ground or mild inclines. It will be a 15-kilometer race up the legendary 1,780 meters (5,840 feet) of LAlpe dHuez—described by cyclists as "21 hairpins of pain."

The ride database helps Sagan and the Project Orion team compute "fluid dynamics," to understand what happens to the "dirty air" that flows past and through Armstrongs always chopping legs as well as surrounding tubes, cranks and pedals. The data also allows the team to perform "finite element analysis, showing them the exact locations of stress on the carbon fibers that make up the frame—and where layers of carbon fiber can be reduced.

To this end, the Orion team, which included composite engineers Scott Nielson and Brian Schumann and carbon fiber frame pioneer Jim Colgrove, produced a breakthrough in the companys drive to develop ever-thinner sheets of carbon fibers. This year, some layers of carbon will weigh just 55 grams, or a little less than 2 ounces, per square meter. Thats only slightly more than three times the weight of the plastic that wraps a deck of playing cards (15 grams per square meter).

Its also about a third of the weight of the production model Trek bike that Armstrong used in his initial Tour victory in 1999. In that bike, the carbon weighed 150 grams per square meter.

Even this year, the bulk of Armstrongs latest specially made bike will use sheets of carbon fibers that weigh 110 grams per square meter. But heres where the sensors and strain gauging pay off. Nielson and Schumann looked carefully at the results of stresses placed on every finite element of the frame and were able to replace 110-gram sheets with 55-gram sheets in locations such as the socket that joins tubes together near the handlebars, the rear fork and the seat post.

Once any identifiable weight is shaved off, the design of any Armstrong bike then must factor in Armstrongs own preferences. After all, this is a fellow who can instantly tell if the wheelbase has been altered by 3 millimeters. To provide the desired stiffness, the team will rely on benchmarks from tests performed on the flexibility of the rear load-bearing arms of the bike known as the chain stay. To achieve comfort, the team relies on measures of the stiffness of the frame itself. And to predict jitter—the uncomfortable feeling that the bike is out of control on a serious descent—the Trek team relies on results of frontal impact deliberately entered into the database from crash tests.

Next Page: Out of the tunnel.

Tom was editor-in-chief of Interactive Week, from 1995 to 2000, leading a team that created the Internet industry's first newspaper and won numerous awards for the publication. He also has been an award-winning technology journalist for the Dallas Morning News and Fort Worth Star-Telegram. He is a graduate of the Harvard Business School and the University of Missouri School of Journalism.

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