Zipp catapulted to the top of the race-wheel world after 2003, but the flashy company is facing its stiffest competition yet.

Zipp catapulted to the top of the race-wheel world after 2003 Tour de France riders adopted its 404. But the flashy company is facing its stiffest competition yet.

This article originally appeared in the November/December 2011 issue of Inside Triathlon.

Zipp’s sparkling 73,000-square-foot office and factory in suburban Indianapolis is barely a year old and it’s already starting to overflow with people and machines. Their technical director, Josh Poertner, strolls through the factory with his polo tucked into the beltless waist of his jeans, past the pressure-controlled carbon prepping clean room and rows of $100,000 mold presses. When Poertner joined Zipp, he was only the third engineer on staff. Today he directs the 28 engineers who design and oversee production of Zipp’s wind tunnel-vetted, carbon composite race wheels that have more in common with Boeing products than the box-section wheels raced by every rider in the Tour de France as recently as 2001, and which date back to the early 1900s, when riders packed cigarettes along with their spare tires. Although some outsiders and competitors claim Zipp has succeeded because of its marketing department—and effective marketing certainly has maximized the company’s exposure—Zipp employees gristle at that notion and then roll their eyes with a twinge of exasperated anger. Within the walls of Zipp, Poertner and his team of engineers are put on a pedestal as the driving force behind Zipp’s growth, and they enjoy almost celebrity status.

Poertner fits the stereotype of the analytical, inquisitive and slightly nerdy engineer, but he has the confident swagger and loquaciousness typically associated with a star athlete, not a star intellectual. Poertner says he is still in disbelief over Zipp’s success, but his confident grin says otherwise. He radiates the impression that Zipp’s meteoric rise to its current position as the world’s premier race-wheel company was the appropriate, although certainly not inevitable, outcome for the engineering-oriented company based an ocean away from the European epicenter of cycling.

Zipp has grown from a tiny shop making wheels, frames and mountain bike parts to the company with more wheels ridden at the Ironman World Championship in Kailua-Kona, Hawaii, than all others combined because it has done the best job of developing wheel technology and showing riders that their products actually make them faster.

But Zipp’s stranglehold on the right stuff is threatened now more than ever. Start-ups and established brands alike that until recently were an afterthought in the race-wheel market have gained ground on Zipp’s aerodynamic superiority. Indeed, the all-important patent Zipp shared with Hed Cycling that gave the two brands exclusive rights to the fastest known rim shape of the 2000s expired in 2009. Without the protection of that patent, Zipp now must out-innovate the industry to retain its throne atop all other race-wheel companies.

***

In 2000, Andy Ording, Zipp’s owner at the time, and his newly hired engineer, Josh Poertner, were hawking aerodynamic performance to road cyclists as the most important element of a wheelset—all while most wheel makers were still stuck on weight and spoke lacing patterns. Zipp’s marquee 404 wheelset had a 58mm-deep carbon fiber rim designed to reduce aerodynamic drag instead of an aluminum rim intended only to create a structurally reliable wheel. Only a couple other wheel makers shared Zipp’s dogmatic belief in the importance of wheel aerodynamics for road cyclists. Although Zipp could have abandoned road racing and attempted to carve out a niche supplying wheels to triathletes, duathletes and time trialists—racers who were already accepting of aero wheels—the company knew its long-term success depended on gaining acceptance in the larger road cycling market. To accomplish that goal, the duo set off to Europe to court a professional cycling team competing at the highest level.

Although one can use mathematical equations to demonstrate that aerodynamic drag, not weight, is the key equipment attribute that influences cycling performance, the European traditionalists that Ording and Poertner were courting weren’t buying it. After all, this duo of outsiders was attempting to convince team bosses that a century of knowledge passed down by the sport’s greatest champions and most respected innovators was wrong.

Triathletes live in a culture that accepts technological progress based on verifiable evidence, but the world of European cycling is different. Poertner, who raced in Europe in the mid-’90s as a junior, remembers the community as “a very old wives’ tale world.”

While training and racing under the guidance of respected team leaders in the sport’s hallowed ground, he was told “you couldn’t have a plant in your room because it over-oxygenates the atmosphere and you won’t produce enough red blood cells. And you couldn’t sleep in a room with the window open because you’d get sick. They had, and still do have, a lot of very strange, very historically based beliefs, and they’re hard to get out of. … They live in this insane world,” recounted Poertner.

Myth-oriented reasoning seemed insane to Poertner, but peers from his racing days had been taught by their most trusted role models that sleeping next to a plant made them slow, and the majority of them didn’t question it.

The same willingness to accept tradition as fact lingers today, and some riders continue to eschew scientific data in favor of traditional thinking.

“[Alberto] Contador today will tell you, ‘I know what I feel. The [lighter and less aerodynamic] 202 is the fastest wheel. I don’t believe the power [meter].’ It was really hard to convince not so much Alberto, but his mechanic Faustino [Muñoz],” of the value of aerodynamic science, Poertner said.

Poertner and Ording spent a year and six trips overseas attempting to crack this mind-set before they met Bjarne Riis, the director of Team CSC and 1996 Tour de France winner.

Riis listened to Poertner and Ording’s justification for deep-rim carbon wheels and took interest in their aerodynamic data. He prescribed Zipp 404s to his riders tasked with going off the front to win races but hesitated to distribute them among his support riders because he thought staying within the shelter of the peloton eliminated the influence of aerodynamic drag. Poertner returned to Indiana and conducted a low-budget test using an SRM power meter, a car and about 15 Zipp employees on a group ride to demonstrate that aero wheels actually help all riders, not just time trialists and those who ride off the front of the peloton.

“We basically had to take an SRM and do a simulation and come back [to Riis] and say, ‘Here’s an 8-minute TT simulating a ride to the front of the peloton from a team car.’ I think that was compelling to him,” Poertner said.

This simple demonstration was enough to convince Riis that aero wheels belonged underneath all his riders, and Poertner saw this as a turning point—not just for Zipp but for the cycling industry as a whole.

“You look at the Tour in 2002 and count eight aero wheels in the whole peloton. Then you look at our first year with Team CSC (2003) and there were nine guys on [aero wheels], and then you look one year later and it’s 80 percent of the peloton.”

Now, almost all riders use aero wheels for flat races, and many keep them on their bikes for days in the mountains as well.

“[With] the math, the science and the reality, it was bound to happen some day, but, as Andy Ording used to say, ‘We bashed a hole in the wall with our head and everyone else got to walk through,’” Poertner said.

***

Zipp was not the world’s preeminent race-wheel brand in the mid-’90s, before Poertner and Ording attempted to crack European cycling. Only a few companies were making deep-rim carbon wheels at the time, but Zipp needed to take a technological leap forward before it was able to sign Team CSC and become a fixture in triathletes’ bike shop fantasies. That technology was rim shape. Although spoke count, spoke shape, hub construction and weight are all important characteristics of a race wheel, the aerodynamic performance of the rim is the dominant trait—and on this point Zipp had a problem. Steve Hed, the namesake of Hed Cycling, and his then business partner, Robert Haug, had a patent protecting the fastest rim shape of the time, which still closely resembles today’s best aero wheels. Hed and Haug called the shape “toroidal.”

The toroidal rim has an elliptical profile when cross-sectioned that is “about 1.05 to about 1.25” times wider than the tire, according to the patent, with the broadest point partway between the tire bed and the spokes. Instead of building aero wheels with a V-shaped rim, which was the dominant shape at the time, Hed and Haug asserted in U.S. Patent 5,061,013 that a bulbous rim with a football-like cross-section would create a “wheel having good aerodynamic properties and good crosswind stability,” and this approved patent gave the pair exclusive rights to that rim shape.

In 1999, eight years after Hed filed that original patent, Zipp filed a patent on the rim shape they call hybrid toroidal and used this design to protect the 404 wheelset they were already building. Instead of blending the tire with the rim to create a continuous aerodynamic profile as listed in the Hed/Haug patent, a hybrid toroidal rim has a bulbous deep section of the rim and a narrow brake track. The thin brake track sandwiched between a wide tire and even wider rim created a figure-eight shape, not a continuously toroidal shape. Wind tunnel testing confirmed these wheels are fast, but Zipp and most other companies have since abandoned narrow brake tracks in favor of the wider design listed in the document Hed and Haug filed. Zipp had a good wheel, but Hed seemingly owned a monopoly on the shape that would dominate aero wheel design for the next decade, and this seminal piece of intellectual property prevented Zipp from designing a rim that smoothly integrates the brake track with the rim’s deep section. Hed Cycling seemed to have secured a major technological advantage, but the relationship between Hed and Haug deteriorated, and Haug offered to sell his portion of the patent to Ording and Zipp. Ording eagerly accepted. Buying Haug’s share of the patent granted Zipp the rights, shared only with Steve Hed, to sell wheels with a fully toroidal rim. Owning a share of this patent gave Zipp the ability to build the fastest rim shapes they knew of without legal hindrance. In 2004, Zipp used these rights to make the 808, a fully toroidal rim 34mm deeper than the 404. It had an exceptionally broad rim—27mm at the widest point—and a sloping brake track that continued the toroidal shape through the entire rim. The release of the 808 coincided with Zipp’s explosion as a company and the widespread adoption of aero wheels by age-group triathletes.

At first glance, the toroidal shape fails the “eye wind tunnel” test. It doesn’t look very aerodynamic. But the toroidal shape is so powerful because it helps reduce drag when riding in moderate crosswinds, the condition most commonly faced by cyclists. Although rim depth has become the characteristic most frequently associated with an aerodynamic wheel, rim shape is equally or perhaps even more important than depth.

The majority of the wind resistance faced by a cyclist comes from pressure drag, the dominant component of a rider’s total aerodynamic resistance. Put your hand out the window of a car with your palm facing forward and you can immediately feel the pressure against the front of your hand, but the less-perceptible low-pressure zone behind your hand is an equally important component of the fluid drag you are fighting. If you were to increase the pressure behind your hand without changing the pressure in front of it, the total drag on your hand would plummet. This is because pressure drag is the difference between the pressure at the front of your hand and the back, and the bigger the difference, the greater the drag.

When the air approaches your hand, it collides with the surface, which increases the pressure at the front of the palm. After fighting its way around your hand, air immediately rejoins the surrounding airflow and it flutters violently. This uncontrolled flapping reduces the pressure behind your hand, increasing pressure drag. To reduce pressure drag, an object must allow air to smoothly pass around its leading edge while guiding it off its trailing edge. As Zipp design engineer Michael Hall puts it, “when designing for low drag, you want to give the air as smooth a surface to attach to as possible” to allow air to easily pass off the back of the object rather than fluttering and creating that dramatic low-pressure zone behind the object. Aero wheels do exactly that by creating a surface—the deep-section rim—that controls the airflow around and off the object. But not all rims of equal depth are equally effective at guiding the air.

Even a subtle crosswind dramatically affects the angle between the rider and the wind, known as yaw angle. The bulbous toroidal rim shape is effective in wind conditions riders face most frequently, crosswinds—not just direct headwinds, which are quite rare. As air wraps around the rim from an angle other than head on, it needs a place to re-attach to the rim or pressure drag spikes. Unlike toroidal rims, deep V-shaped rims are narrow where Zipp believes they should be broad—somewhere around the center of the rim—so the passing air cannot easily reattach. This simple change to fatter rims provided the foundation of Zipp’s growth from underdog to behemoth. As a result of the shared intellectual property granted by Hed and Haug’s patent, Zipp and Hed Cycling were able to dominate the race for aerodynamic performance through the last decade, and Zipp in particular turned that into a business explosion. Zipp won the Kona wheel count in 2005. In 2007 and every year since, more Zipp wheels have been ridden in Ironman Hawaii than all other wheels combined. Cycling component giant Sram bought Zipp that same year and gave them the resources to continue to grow at a torrid pace.

When Zipp and Hed’s toroidal rim patent expired in October 2009, many observers expected a deluge of toroidal wheels to hit the market on that very day, and that didn’t happen—they are only now beginning to arrive en masse. But the expiration of Patent #5,061,013 forced the two pioneers of aero wheel design to immediately venture beyond the shelter of the patent and create rim shapes that are faster than the toroidal rims in anticipation of the rest of the market catching up to their 2009 technology. But these new designs are not their exclusive property. Ironically, Zipp has innovated themselves into a more competitive landscape. Zipp’s new rim technology called Firecrest—it’s actually much more bulbous than the original toroidal wheels—and Hed’s Stinger wheels, with an equally broad design, reveal some of the key attributes of aerodynamic design that neither company has yet been able to protect with a patent, although both are pursuing patent protection for their designs. When they designed a faster yet unprotected rim shape, the technological monopoly Zipp and Hed enjoyed for years evaporated. And the list of wheel makers fighting to convince triathletes that they, not Zipp or any other company, make the best race wheel has mushroomed.

Although there wasn’t an explosion of toroidal wheels the day the patent expired, many wheel makers recently have incorporated wide rims into their aero wheels, and several serious wheel companies have overhauled their rim design with characteristics resembling Zipp’s Firecrest. For example, Bontrager recently unveiled a complete line of extremely broad carbon race wheels; Enve commissioned the assistance of a former Formula 1 aerodynamicist to design its newest aero rim shape, which is similar to Zipp’s; Reynolds Cycling produces shockingly expensive wheels constructed almost entirely from carbon with a unique rim shape based on a very broad rim; and, as they have been for decades, Hed Cycling is still at the upper limit of aero wheel performance. And many more brands are aiming squarely at the Indiana-based company.

***

We’ve got to stay out of the ‘easy’ business,” Poertner said.

He describes Zipp’s future as hinging on a procession of increasingly complex products so difficult to reproduce that competing companies will struggle to replicate them even when provided with a blueprint.

Poertner is fond of comparing this strategy to Toyota’s willingness to show any visitor how it makes cars in its factories. Although Zipp doesn’t grant that level of access, Poertner believes that other companies might look at Zipp’s products and determine what they do and how they work without being able to figure out how to build them.

“We’ve developed more ways to fuck up a rim or a wheel in the last year than we knew existed,” Poertner boasted. “Each next layer of technological advancement comes with an entire layer of burden for fuck up.”

Poertner seems to be motivated by a desire to have the intellectual high ground above his peers at other wheel companies, but convincing everyday cyclists, not other composites engineers, that Zipp’s products ride better and faster than everyone else’s is the challenge Zipp faces if it’s going to maintain its title as the Wheel Triathletes Most Desire.

Zipp’s first step in this new direction, and beyond the protection of the toroidal rim patent, is an entirely new rim design philosophy embodied in its Firecrest rims. This new generation of rim technology focuses on two attributes of wheel performance that were overlooked in previous designs. Not only does the Firecrest rim concept have an exceptionally broad brake track to blend the tire with the wheel, but the rim’s widest point is closer to the spokes than the tire, a reversal from the toroidal design. Broadening the deeper portion of the rim allows the spoke bed—the innermost segment of the rim that faces the hub—to have a gently curving profile. According to Poertner, this design gives the rim good aerodynamic properties not only when the tire is the leading edge, but also in crosswinds when air strikes the spoke bed first, effectively making the spoke bed the leading edge and reversing the shape of the wheel. This gently curving spoke bed also improves stability by allowing air to easily pass off the side of the rim rather than building up and releasing in large bursts, which creates a strong, unpredictable steering influence. Almost on cue, other brands are now mimicking Zipp’s new ideas about the importance of stability and the concept of the spoke bed as a leading edge.

Poertner has transitioned from day-to-day product development to a big picture and business leadership role, and the responsibility of producing the next hit product has been handed largely to Michael Hall and the rest of Zipp’s team of baby-faced engineers. Hall, the designer of the Firecrest rim shape, came to Zipp from a tiny aerodynamic testing company that provided aerodynamic consulting for racecar teams running General Motors engines. The rule-bending culture of race car engineering taught Hall to push boundaries.

“All throughout engineering school, I was always taught to be conservative,” Hall said. “So much of engineering is about being precise and correct and knowing a direction. What I learned [in that job] was out-of-the-box thinking.”

Instead of looking toward aerospace engineering for ideas, Hall is mining windmill technology for ways to optimize cycling aerodynamics, largely because the wind speeds and yaw angles experienced by windmill blades, according to Hall, resemble cycling conditions. These concepts, a diverse posse of engineers and Sram’s investment can help Zipp fight off its encroaching competitors, but there is no way to guarantee Zipp will come up with the Next Big Thing in race-wheel technology. Nevertheless, Hall and Poertner like their chances.

“Over the years we’ve hired so many good engineers and we have a really good core of people,” Hall said. “I would put our engineering staff against any company in the world. In a head-to-head match-up with any of our competitors, I would go to bat with our team any day. We have the structure, the resources, the funding. So, yeah we lost a little bit of protection [from the toroidal patent] but given everything we’ve set up, I think we’re just going to keep plowing ahead.”