Equinox TTX

Wind Tunnel Testing: The Proving Ground

For Trek, the road to superior bicycle aerodynamics starts with a sound understanding of aerodynamic principles. These principles are then applied to conceptual designs that can be analyzed using the “virtual wind tunnel” of Computational Fluid Dynamics before a prototype even exists. But aerodynamic design is a complex process. For all the black and white “rules” governing the flow of air, there are still plenty of grey areas. In fact, because relatively little research has been done on the flow field of bicycles (as compared to higher speed vehicles like airplanes and Formula 1 cars), low speed aerodynamic study presents an even bigger challenge.

That’s where the engineering and design expertise of Trek’s Advanced Component Group (ACG) comes into play. With the collective wind tunnel experience gathered from dozens of aerodynamic-specific events conducted for more than a decade, Trek’s ACG has started to reduce the amount of grey surrounding bicycle fluid dynamics. Don’t misunderstand. A keen understanding of aero theory and access to the latest CFD software are excellent starting points. But “book learning” is no substitute for experiential knowledge. When it comes to designing aerodynamically proven bicycles, Trek leads the way in experiential knowledge.

Internally Routed Cables

By routing them internally behind the stem, the brake and shifter cables are kept out of the wind, leaving a “clean” frame surface that maximizes aero efficiency.

A Clean Leading Edge

The hourglass-shaped head tube, integrated headset, and internal cable routing behind the stem give a clean presentation to the wind.

By designing the Equinox TTX with a lowered down tube, Trek’s ACG was able to reduce the gap to the front wheel, creating a virtual continuous surface with less drag and better aerodynamics than conventional designs.

Not only is the Equinox TTX’s down tube in the best location relative to the front wheel and fork, its also got a shape that’s optimized for superior aerodynamic performance. While some competitors build frames with stylized, “aero shaped” down tubes—which are in fact more aesthetically interesting than they are aerodynamic—Trek carefully considered the direction of the air flow when designing the TTX’s down tube. The result is a properly shaped aero tube that slices through the wind with maximum aero efficiency.

The wind-cheating groove on the Equinox top tube allows this bike to steer and handle confidently on any course while maintaining unmatched aerodynamic properties. No bike can claim to match the combination of aerodynamics and lateral rigidity. Go ahead; eat, drink, dive into a corner, Equinox holds steady underneath you so can sit back, let speed devour you, and still run a marathon when you’re finished.

Whether you have a 5k, 10k, or marathon ahead of you, you can’t afford to waste valuable energy by having to come in and out of your aero bars at every little corner. TTX has established the perfect balance of a key component of bike geometry known as front-center to keep you aero and save vital energy.

When building a Triathlon bike, front-center is extremely important. When your weight is added to the front end as you rest on the aero bars, it tends to make the bike more prone to over-steering (become less stable). An increase in the front-center will increase stability, but too long of a front-center will make the bike more prone to under-steering (more difficult to turn).

So, to build a bike that handles correctly when rider weight is predominantly resting on the front end, the perfect balance of front-center must be established. Trek engineers have spent tens of thousands of hours in the design lab, on the road, at Ironman competitions, and winning 7 straight Tours de France to establish unmatched handling performance. And the result is a bike that saves precious energy by tracking and steering reliably.

Regardless of the length of multisport event, staying properly hydrated and maintaining appropriate energy stores are the difference between achieving a personal best and “bonking” before the finish line. With water bottle mounts placed higher for easier access to water, and an ultra stable design that lets you eat and drink without losing control, staying fueled for the run has never been easier.