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The team at Trek Bicycle Corp. is no stranger to complex feats of engineering. With icons like Lance Armstrong and Travis Brown as their guides, Trek engineers regularly stretch the limits of carbon fiber materials and crank and derailer designs to make the company’s highly technical road and mountain bikes feather-light with the ultimate performance.
The Trek development team recently found itself facing a different kind of assignment: Creating a back-to-basics-style bike that would have mass appeal to non-bikers. Instead of putting technical wizardry on display, the bike design called for high-tech componentry to be tucked behind the scenes. Aesthetics like seat comfort and ease-of-use around braking and shifting took precedence over traditional gear-head features like chain stays and drive trains. The result of the effort is the $550 Trek Lime, a retro-style bike with an automatic shifting system, flip-up trunk seat and changeable color “peels” that put the teams at Trek and its component partner Shimano to a novel, but equally challenging engineering test.
“We’d been playing in the high-end game, tweaking off grams and refining materials and putting our intense engineering efforts around that,” says Hans Eckholm, a senior industrial design engineer at Trek, which is headquartered in Waterloo, WI. “Our products designed for casual riders had not gotten the engineering attention other products had. When you can’t rely on the user to control all the things they typically control – derailers, brakes and such – you need to make those things function well and be hidden, and that took some creative engineering.”
Along with keeping the team focused on non-traditional engineering goals, the Lime project veered off from Trek’s standard R&D practices in other ways. Research conducted with the average consumer, not bike enthusiasts, played a huge role in shaping the Lime’s design. Since the bike is based on Shimano’s Automated Coasting System, Trek engineers had to engage in a higher level of collaboration and CAD file sharing with partners outside of its own core R&D group. Finally, channeling engineering energy into a bike aimed at non-bikers was a mind-set shift for many developers in both the Trek and Shimano camps.
“Bikes for the masses typically don’t require a lot of high-tech engineering, so we weren’t looking at innovation, but rather to put a good valued product out there,” says Chad Price, Pavement Bike product manager at Trek. “We weren’t necessarily in tune with the customer in terms of changing trends.”
The 161 Million Market Opportunity
There was good reason for both Shimano and Trek to redirect some of their engineering horsepower to the everyday-consumer market. While the partners each had enviable traction in the high-end bike enthusiast market, that segment as a whole wasn’t expanding beyond its already hard-core following. Shimano in 2004 enlisted industry leader Ideo to conduct market research into bike buying patterns and usage. The results were startling: While there was a market of around 30 million bike enthusiasts, there were 161 million people in the U.S. alone who could ride a bike, but weren’t, for whatever reason. “It became abundantly clear that bicycling wasn’t on a lot of people’s radar’s screen,” says Shannon Bryant, project coordinator for Shimano’s Coasting System. “We needed to go outside of cyclists and talk to non-cyclists.”
With the help of Ideo, Shimano did just that. At the same time, Trek was conducting its own research with mainstream consumers to find out why more people weren’t riding. Both sets of research determined that people who hadn’t ridden for some time were intimidated by multiple gears and complex shifting systems and didn’t feel comfortable using cable hand-braking systems. This untapped market, the research showed, longed for a simple bike that reminded them of childhood. “Expecting someone to learn how to shift is a pretty tall order for someone who hasn’t ridden since they were a kid and is now 40 years old,” Bryant says.
Shimano was already selling a three-speed automatic coasting system in Europe, which used a computer system to gauge cadence to determine when to automatically shift a bike’s gears. Yet there were complexities with that product that still put it out of reach for this particular market, Bryant says. In a turn for Shimano R&D, which is traditionally internally focused, the Japanese-based company embedded a core set of engineers with Ideo’s U.S.-based research team for six months to gain a fresh perspective, fully digest the research and explore why the average consumer was avoiding the bike shop. “This was an unorthodox direction for us, but we knew we had to think outside the box,” Bryant says. “We had to take off our bike-minded hats and put on a novice hat.”
Based on what they found, Shimano’s engineering group went back to the drawing board to develop a new automatic coasting system that hid even more of the technology. The battery used to power up the computer was replaced with a generator, eliminating the need for riders to manually swap out a battery. The new system was also built to hide all the cabling and braking systems, allowing riders to come to a stop simply by pressing backwards on their pedals, just as they did when riding as a child.
Shifting to A New Course
Shimano shared the Ideo findings with Trek and two other bike companies, Raleigh USA and Giant Bicycles, to get them onboard to build new bike designs based on the Coasting System. Each company had access to the same automatic shifting componentry, but they still needed to kick their own engineering efforts into high gear to differentiate their bike offerings. For Trek, the design goal around simplicity created a unique engineering challenge, particularly in how to conceal all the wiring while keeping the cockpit and handle bar area clean, Eckholm says. Trek engineers had to figure out how to route the wiring through the frame and out a small hole near the pedals to connect to the computer piece (the “brain box” as it was called) of the Shimano Coasting System without degrading the structural integrity of the bike and causing quality issues during manufacturing. In a typical Trek bike, even in the consumer offerings, the wiring is exposed on the outside of the frame. Moreover, spinning the handle bars – a common movement of a bike – had the potential to cut the hidden wiring, so the Trek team had to build a mechanism to keep the handle bars’ movement to less than a full 180 degrees, Eckholm explains.
Using SolidWorks' 3D CAD tool and COSMOS Express and Designer Finite Element Analysis (FEA) capabilities, Trek worked through several iterations to get the structure right. The team would validate a design virtually with the software, create a rapid prototype and then run the prototype through physical testing to determine stability. “With a typical problem, we’re usually familiar enough with what we’re doing that we hit the nail on the head after two or three iterations – this took more like four,” says Matthew Poster, a Trek mechanical design engineer who worked on the Lime project. “There was no easy way to do this … without degrading the strength and integrity of the tubing.”
Accommodating the computer box from the Shimano Coasting System so it wouldn’t be seen was another challenge requiring Trek to rethink its standard bike design. Instead of mounting the box in clear view on the handle bar area, the Lime design called for it to be tucked near the pedals, requiring Trek’s standard kickstand to be modified without it appearing kludgey to the average rider. “There was a lot of complex engineering in keeping this bike simple,” Poster says. “There was no room for gaudy cables or brackets – we had to keep everything as clean and out of sight as possible so when a user was on the bike, they didn’t realize anything. They could just ride.”
Another engineering challenge came with the Lime Peels, a unique part of the bike’s design that allows riders to easily change the bike’s color and style. These swappable components fit over the bike’s hub covers, chain guard and handle grips. “The on-off requirement presented a bit of an engineering challenge,” says Eckholm. “The materials had to be flexible enough to snap off, but robust enough to stay on.” Trek ended up using special rubber materials to accommodate this requirement, but it took some heavy-duty collaboration with Shimano R&D and Trek’s Asian manufacturing partners to ensure the design would work with the Automatic Coasting hub. “Having a unified system around SolidWorks helped us better coordinate with Shimano and the manufacturing partners so they could do their part,” he adds.
There were other collaborative challenges associated with the Lime project that were out of the ordinary for traditional Trek R&D. Consider the Lime’s flip-up, trunk-style seat. While Trek engineers typically push the envelope with aerodynamics and weight when it comes to seat design, with this bike, functionality was at the fore, Eckholm says. Ideo research showed this class of potential riders wanted a place to store keys or cell phones – thus creative juices had to be steered towards coming up with a cool way to accommodate the need without impacting the aesthetics of the bike. “While our carbon fiber bikes are more challenging from an engineering standpoint, trying to get everyone on the team onboard with the goals and what we learned from the research was the challenge,” Eckholm says. “Someone who knows a ton about bikes is not going to be excited about a big saddle with a trunk on it.”
Collaboration was also stepped up, to some degree, not just between Shimano and its initial three partners around the Automatic Coasting System, but among the partners themselves. Shimano committed to fund and participate in a broad marketing campaign around coasting, and the OEMs regularly shared some ideas despite their need to differentiate, Shimano’s Bryant says. By the end of this year, Shimano expects to have 10 partners signed on to produce coasting-style bikes.
“It’s been an exercise in diplomacy,” she says. “At first we weren’t sure what to expect, but what you see is three bikes, each with a distinct personality. Even though the OEMs are competing, it’s been kind of like the G8 Summit – we’re all trying to share to create a growth opportunity for the entire industry.”