This story originally appeared in the July/August 2011 issue of Inside Triathlon magazine.
Every triathlon bike worthy of a spot in transition is designed to optimize rider and machine aerodynamics—and with good reason. Other than improving fitness, minimizing aerodynamic drag on the bike is arguably the best way to go faster. This focus on aero resistance has made wind tunnel testing an indispensable tool when designing a new tri bike—whether or not the bike is priced in the five-figure stratosphere like the completely redesigned 2011 Felt DA. Although this move to quantifiable aerodynamic development has greatly improved tri bike quality across the board, the focus on wind drag has left every other attribute in the darkness. But a bike with a low drag coefficient doesn’t have to sacrifice ride quality and comfort. Felt has done its homework in the wind tunnel, and its engineers say the DA has the drag characteristics to match, but the 2011 DA’s most distinguished trait is the harmony it creates between rider and bike due to its geometry, front-end stiffness and stunning component kit. But enjoying all these characteristics comes at a steep price: $12,499.
Many of the most aerodynamic triathlon bikes are built with a narrow front end. It only makes sense: Reduce the frontal surface area and wind resistance might decrease. But narrowing the downtube and head tube also reduces the bike’s side-to-side stiffness. Not only are many tri frames flexible, but the headset and aerobar spacers used by many riders to find their ideal fit add another layer of bendability to the bike. As a result, many tri bikes sitting in transition have very flexible front ends.
The Felt Bayonet III fork connects the fork blades to the aerobar attachment system with a piece that extends in front of the frame. This extension is designed to reduce aerodynamic drag, and it also buttresses the head tube and greatly stiffens the DA’s front end. As a result, the bike calmly tracks through corners without wobbling or swaying under the stress created by leaning into a tight bend or accelerating out of the saddle. The DA has quick handling characteristics, but the bike is never overwhelmed by a turn.
Shimano’s Dura-Ace Di2 is the best tri component group available, bar none. That opinion isn’t exactly controversial—more than $1,000 separates it from the next priciest option—but the benefits of Di2 are undeniable. It shifts more precisely and rapidly than any mechanical kit, and it simply does not come out of adjustment. In addition to the transcendent shift quality, Di2 allows the rider to shift while in the aerobars or from the brake levers. This lets the rider select the ideal gear at all times, even when he or she is forced out of the aerobars. No more grinding up hills or sprinting out of a corner while over-geared.
In addition to the otherworldly drivetrain, the DA is equipped with Felt’s outstanding Devox carbon aerobars with slight-upturn extensions that create a pleasant and reassuring amount of tension in the wrists. A Zipp 808 front and 1080 rear tubular wheelset finishes the package and makes the DA race-ready out of the box. Because the bike is equipped with race wheels, the rider will need to find another pair of training wheels for everyday riding.
The brake calipers are the only weak spot. Both calipers are partially hidden by the frame, but they lack stopping power and the rear feels squishy due in part to the full housing leading from the lever to the brake.
The DA’s stack and reach values—its frame fit specifications—are moderately aggressive as compared to other tri bikes. This foundation allows for a fully rotated triathlon position but doesn’t require a position too demanding for most triathletes. The frame’s fit—stack and reach—is only one component of the DA’s complete bike fit.
A bike with a traditional front end has headset spacers and stem options that can be swapped to accommodate a wide range of fits. The Bayonet III system replaces the headset spacers and stem with a single, rotatable extension to connect the bars to the frame. This unique attachment system reduces the bike’s range of fit adjustment when compared to a standard front end, but still offers substantial adjustability. With the shortest extension piece, the DA’s aerobar can be positioned like the bike is spec’d with a 96mm stem positioned between 1 and 38 degrees above zero. The aerobar attachment piece can be swapped for a longer version, but it cannot be shrunk.
The Devox aerobars provide ample extension reach adjustability, but the pads themselves cannot be drawn back to the rider dramatically. The bars do offer the ability to fine-tune the elbow pad reach, and they can be raised substantially. The Bayonet III and Devox bars create a wide range of adjustability, but they struggle to accommodate a short reach distance from the rider to the aerobars or a low stack height to the top of the bars.
Every bike company wins its own wind tunnel test. I have never seen a piece of wind tunnel data published by a bike maker that shows a competitor’s bike to be superior to its own. Although it is of course impossible for multiple bikes to have the lowest drag coefficient, test conditions can be set to favor one bike over another. This ability to manipulate the results of a wind tunnel test makes it unwise to put too much stock in a manufacturer-funded wind tunnel test stating that it has the “world’s fastest bike.” A bike brand comparing two if its own products, however, carries more credibility. Instead of stacking the DA up against high-end tri bikes from other manufacturers, Felt compared the 2011 DA to its predecessor. The 2011 DA creates roughly 10 to 15 percent less aerodynamic drag than the 2010 version, depending on the yaw angle, according to the test published by Felt.