Technical FAQ with Lennard Zinn: Armstrong’s aerodynamic TdF suit

Rubiera

Photo: Lennard Zinn

Armstrong won on a special superlight prototype aero’ bar that Deda had whipped out for him for the Tour. It is completely flat; there is no drop to it like the Vision Tech bars the team has used in the past and still has on some of its time trial bikes.

It is made out of aluminum, but according to Deda’s Fulvio Acquati, “We are still working out the exact design with Armstrong, and when we get it exactly the way he wants it, we will make it out of carbon.” Deda also has a carbon aero’ bar that Acquati was showing to the teams the day before the prologue. The carbon base bar is just a prototype, and he was asking for input from various team mechanics on it. But the aero’ extension is complete, and he delivered one or two of those to a number of Deda-sponsored teams.

The aero’ extension is a single superlight carbon tube that splits into two barrel-shaped handles with aero’ shaping at the crotch. There is abridge that can be pressed into the ends if the rider opts against bar-end shifters in them. A single-sided clamp that clamps the base bar right next to the stem holds the extension centered above or below the stem. It comes in both 26.0mm and 31.8mm bar-clamp sizes.

Slippery clothes and horsepower
Another new technology on the U.S. Postal team was its clothing. The riders were wearing new skin suits with special triangular panels extending down their sides from their underarms, although Armstrong’s personal skinsuit was different than those of the rest of the team.

According to U.S. Postal aerodynamics advisor John Cobb, “The suits were made by Giordana, who makes clothing for Nike, with some stitching instructions from me. I was at Lance’s house in May, and he told me that Giordana was making him some new suits. I had been working for years with Nike in the wind tunnel on some new super-fast clothing designs, and I told Lance that if he was having some new suits made, that he ought to include some of the work we had been doing. I sketched out where they should put the seams so it would be fastest and how to orient the fabric. Lance said that he did not think he could get Giordana to do that, since they are Italians, and they won’t want to change the way they do things.”

Cobb said he figured he would make the most compelling argument he could.

“I told them ‘Well whatever, but if they want get you 30-45 seconds over a 40 or 50K time trial, they will,’ and I walked out,” Cobb recalled.”I had missed the last wind tunnel session with Nike because I was in Taiwan (working on some new carbon aero’ forks and handlebars), so I don’t know if they ended up getting the special fabric we had been working on. We were trying to get a new fabric made in France that literally costs like $3000 a yard. I don’t know if Nike shared that technology with Giordana, though. But where the seams are and the direction the material runs, for instance, on the inside and outside of the legs, makes a big difference.We discovered this when we were working in the wind tunnel trying to figureout why aero’ seat posts don’t work, which they don’t – ONCE would be a lot faster if they got rid of theirs.”

The suits of the Postal riders besides Armstrong’s were a different blue than normal, and the shorts were not completely black (sort of a dark gray) except under the saddle pads. The triangular panel under the arms was white, and the curving of the side seams around onto the lower backwas quite noticeable. The Trek logo on the shoulders was just printed in white, rather than being a large white panel. “They had to do that to getthe shoulder seams right,” remarked Cobb afterward.

Armstrong’s suit, however, looked to be the standard Postal blue withblack shorts, and the Trek logo on the shoulder was in the standard whitepanel. The single noticeable unique feature, at least at the speed he zoomedby, was that he had long sleeves and his gloves were integrated into hissuit. Otherwise, it was hard to see how it differed from a standard skinsuit.Cobb chuckled, “He could have been wearing a sandpaper suit on that shortcourse today and it wouldn’t have mattered — it was just horsepowertoday.”

As for what else might be in store, Cobb smirked, “We have some otheraero’ equipment hiding in the wings if things go bad!” So far, things seemto be going quite well for Armstrong and co.

Steve gets his decal
After many years of providing the three-spoke front wheels on whichLance Armstrong has won Tour de France time trials, Steve Hed isfinally getting the recognition that has been lacking from that commitment.Now that Hed is an official aero’ equipment supplier for the U.S. PostalService team, Hed decals now adorn the Hed3 three-spoke front wheels thathave been unmarked in Armstrong’s previous Tour de France time trials.ONCE was also using these wheels on the front, as they did last year aswell, but theirs only have ONCE decals on them.

The Hed3 wheel is the same wheel as the former Specialized/DuPontwheel on which Graeme Obree set world hour records, with some changesin the carbon lay-up and the aluminum rim extrusion. Hed took over theSpanish wheel factory from DuPont three years ago, and long-time DuPontemployee German Lastra continues to direct the production.

Rear wheels
A new product out of Hed’s Spanish factory is a rear disc wheel withthe Hed3 structure inside it, called the “Hed 3D Disc.”

Armstrong and his team did not use it in the prologue, though, insteadopting for Mavic rear discs. The explanation, according to Armstrong andU.S. Postal aerodynamics advisor John Cobb, is that there is a clearanceissue.

“When we (Trek engineers and Cobb) designed those time trial frames,we never dreamed that they (U.S. Postal riders) would use bigger than a19mm tire in there. But they will only use 22mm tires because they areafraid about getting flat tires. On sharp corners, a 22mm tire hits theinside of the chainstays. The deep cut for the tire in the center of theMavic disc reduces the side flex of tire sidewall when cornering enoughthat it won’t rub. The 3D Disc is fast, but it would have been stupid tohave made another frame mold just so that wheel could clear. On less extremecourses, there is no problem. In fact, Lance used the 3D Disc in the Dauphiné(where he won the overall last month). U.S. Postal might still use the3D in the team time trial, though, because the clearance problem that isa much less curvy course.
Our wind tunnel tests show the 3D Disc is way faster than flat discs.It is also faster than the Mavic, but not nearly so much – maybe eightpercent, because the Mavic is also somewhat lens-shaped. The Mavic is prettygood anyway.”