FELT INTEGRATED AERO You are looking at the most advanced triathlon bike in the world. IA stands for Integrated Aero. To create this bike, Felt assembled a team of athletes, engineers and product developers, and challenged them to rethink every element of aerodynamic performance. To forget about limitations and dream of new ways to build not just a faster bike, but a fully integrated machine that interfaces more seamlessly with the human form. The result is a bike that has been obsessively engineered, tip to tail, to give competitive riders a real-world advantage in the race against the clock. The story of the IA can be seen it its design. In its progressive shapes, its attention to ergonomics, its out-of-the-box thinking on full-system integration. There are dozens of new technologies and design details that make up this story. But what matters most is one simple thing: Results. And that s where the Felt IA shines brightest. As you ll see in the data compiled on page 10, the IA proved in wind-tunnel tests to be significantly more aerodynamic than some of its key competitor bikes.
Evolution of the Machine For more than two decades, Felt has been the industry leader in aerodynamic engineering. The IA is a culmination of everything Felt has learned over 23 years of collaborating with many of the world s top triathletes and cyclists. Here is a brief history of Felt s critical breakthroughs in the race against the clock. 1989: Jim Felt, a custom framebuilder in California, began crafting aerodynamic bikes for local triathletes. One of his first bikes was built for motocross star Johnny O Mara, who was competing in triathlons as training. 1991: Jim Felt designed and developed (with use of the SDLS Wind Tunnel) a new aluminum aerodynamic bike for triathlon legend Paula Newby-Fraser. The frame, named the B2 for its matte-black finish and stealth look, helped Newby-Fraser win the 1991 Hawaii Ironman event. 2002: The Felt DA 650 was introduced. Innovations included its bladed downtube, flared bottom bracket area and CNC machined wishbone seatstay. 2003: The first S22, a sub-$1500 TT/ triathlon bike that had many of the same design features and technologies as bikes costing thousands more, made aerodynamic gains available to more consumers. 2006: An all-new carbon-fiber DA, developed with exhaustive windtunnel testing, debuted with the first Bayonet Steering System, a technology that placed the fork steering structure outside of the head tube for improved aerodynamics and handling. 2007: Taylor Phinney rode Felt to the Junior Road World Time Trial Championship and also set the 3,000-meter individual pursuit world record with a time of 3:16.65. 2008: Felt athletes swept the triathlon events at the Beijing Olympics. Australian Emma Snowsill and German Jan Frodeno both won gold on Felt bikes. 2010: American Sarah Hammer rode the Felt TK1, an aerodynamic endurance track bike featuring the Bayonet 2 steering system, to her third world championship title in the individual pursuit. Paula Newby Frasier -1989 2013 - Andy Böcherer 2012: American Kristin Armstrong rode the Felt DA to an Olympic gold medal at the time trial race in London. 2013: The all-new Felt IA is released as part of Felt s 2014 lineup. 90 00 03 06 10 14 DA DA IA B2 S 22 DA
A Triathlon Superbike Never before has a bike been so thoroughly engineered to address every performance aspect for triathlon. A deep history of partnerships with Olympic and World Champion triathletes puts Felt in a unique position to create a better triathlon bike. That athlete collaboration is where the development process begins. VR Seatpost Vibration Reduction seatpost provides excellent shock absorption with the help of 3T s Diff-Lock TM comfort module. The IA project is years in the making. One of our goals was to develop a bike with best-in-class aerodynamic performance but that was just the beginning. The real challenge was addressing other real-world triathlon needs. Comfort, adjustability, braking and steering performance. And we didn t just focus on the bike. It s about the body and bike together. In many ways, our engineers viewed the IA as an extension of the rider. Ergonomics played a role in every design detail. AE RO Many manufacturers use the term system engineered. But the IA takes this idea a few steps further. We abandoned any concerns with UCI road racing rules and limitations so we could create something truly unique. A focused machine with one purpose. Here is a look at some of the key technologies and designs that separate the IA from the crowd. 1. Cloak Seat Stays 2. Vibration Reduction (VR) Seatpost 3. InternaLoc Seatpost Binder Bolt 4. Integrated Rear Brake 5. Sub-Stance Front Derailleur Mount 6. BatPac 7. Aero Bottom Bracket Area 8. All-Aspect Tubing 9. CalPac 10. Integrated Fork Design 11. Cloaked Cable Routing 12. Fully-Adjustable Aerobar 13. Optimized Dagger Aero Head Tube 14. Dagger Front Brake Vibration Reducing 3T Diff-Lock TM Seat Clamp 2 This innovative seat clamp system uses interlocking toothed barrels for fine 0.5-degree adjustment steps, slip-proof performance and a unique comfort module that reduces road vibration to lessen body fatigue during long triathlons or time trials. 3 9 11 12 10 13 8 14 5 Internalock Seatpost Binder Bolt 1 6 The best method of optimizing and dispersing clamping force on an aerodynamic seatpost. Seatpost adjustments remain secure. Easy to remove and travel with. 4 7
AeroPac Cover The storage reservoir integrated into the IA top tube features a silicone cover to securely contain nutrition and hydration as well as retain aerodynamics by blending into the surface of the frame. The cover allows onthe-fly hydration and easy access to stored goods. Aerodynamics Before embarking on the IA project, Felt engineers clearly identified their mission: This would be the fastest triathlon bike in the world. No compromises, no holds barred. That meant considering some realities that don t always come into play during wind-tunnel testing. For example, a particular frame might test fast with a certain body type in a certain position but what if the average rider can t comfortably hold that aero position? Or, what happens to aero performance when the rider bolts on bottle cages, straps on spare tubes, and tapes energy bars to the top tube? For many manufacturers, this is where wind-tunnel comparison tests fall down. CalPac CalPac: Horizontal compartment for energy gels, bars and race supplements. The IA addresses these factors head on. Like all aero projects from Felt, this bike was painstakingly developed through a series of advanced processes including Computational Fluid Dynamics (CFD) and wind tunnel tests. Beyond that, engineers worked extensively with Felt pro athletes like Ironman Champion Mirinda Carfrae and twotime Olympic time trial gold medalist Kristin Armstrong. The development team observed and measured the aero performance of athlete and bike, both in controlled environments and out on the road. Cloak Seat Stays Near-horizontal seat stay design improves aerodynamics by reducing drag. The seat stay is fully faired by a rear disc wheel at wide yaw angles. Frontal area is reduced by nearly 50% compared to conventional seat stays. Ride comfort is improved by inducing leaf-spring effect while lateral stiffness increases from small rear triangle surface area. This is a bike that wouldn t exist without Felt s long history of creating aerodynamic bikes for elite athletes. And even though pro rider feedback is critical, the IA was designed to fit everyday triathletes. With its higher head tube (to eliminate a clumsy stack of spacers) and unprecedented adjustability, it delivers a performance boost without sacrificing comfort and fit. And, most importantly, it helps a wide range of triathletes get into the best riding position so they can experience the aero advantages of the bike. Yet even with these adjustments to optimize the IA s functionality, it still achieves significant aerodynamic gains over other competitive triathlon bikes (see page 10).
3D modeling and CFD analysis allows Felt engineers to fine-tune their designs before the prototype phase begins. While many manufacturers rely on wind-tunnel for marketing purposes they stage tests to find certain advantages they can publicize Felt has a long track record of using wind tunnels as part of its development process. The wind tunnel allows engineers to measure aerodynamic drag on complete bicycles as well as parts such as wheels and handlebars. They can also test certain sections of the bike to make accurate, precise measurements at specific angles of airflow and velocity. In developing the IA frameset, Felt utilized the San Diego Low Speed Tunnel in Southern California, a facility it has worked with for years. It s the combination of CFD analysis and wind tunnel testing that allowed engineers to pinpoint optimal airfoil shapes in multiple areas of the bike. In addition to measuring the effects of certain shapes, they also analyzed the ways those shapes affected others downstream. That type of detailed analysis is impossible to perform in the wind tunnel alone. At Felt, the development process of aero bikes begins with CFD. This branch of fluid mechanics uses mathematics and algorithms to measure aerodynamic performance. With computers and powerful software most often used for aerospace engineering and racecar development Felt engineers can calculate and simulate airflow and wind drag related to different frame shapes and configurations. The CFD software allows engineers to crunch massive amounts of data in as short a time as possible. Felt has spent years optimizing its CFD practices and verifying results in the wind tunnel. The truth is, CFD is still a black art of sorts. There are many different ways of doing things, and it takes years of consistent experimentation to understand and perfect the results. Years of detailed CFD and wind-tunnel tests led the Felt engineering team to explore one aspect of aerodynamci performance that gets less attention than wind-cheating shapes and leading edges. It has to do with a force called lift. Under specific airflow conditions, depending on the angle of attack and relative airflow velocity, most tube sections of the bike generate enough lift, just like a sail does, to counteract the forces of drag. The net effect is reduced drag. This is part of what makes the IA feel fast out on the road. At higher yaw angles, this lift force greatly exceeds the drag force, making drag less significant. Knowing that, Felt optimized certain airfoil sections to produce more lift than traditional airflow shapes. These sections of the frame actually make it possible to build a bike that s faster than the sum of its parts because key areas of the bike produce so much lift that they add negative drag in the direction the bike is traveling. But the pay-off is worth it: Long before any prototypes are built, the shapes of tubes, junctions, components and entire frames can be optimized through the use of CFD. The 2014 IA features Oxeon TeXtreme, a spread tow composite carbon fiber material that was first used in the Nine Series XC hardtail, and most recently, the F-Series FRD road bike ridden by the Argos-Shimano WorldTour team. TeXtreme differs from traditional carbon fiber in the way its individual fibers are configured. To visualize how they work, imagine extremely thin ribbons nested close to one another. This configuration produces a denser, more ideal resin to carbon fiber ratio. So with TeXtreme, less material is needed to produce even stronger frames. TM TM TM The combination of CFD and wind-tunnel analysis also led to the creation of aero frame features like the Dagger Seatstays. But it isn t all about the tube shapes and junctions. Sticking to its mission to develop functional aerodynamic performance, the engineering team spent countless hours creating integrated technologies and features such as the brake system. The brakes were designed concurrently with the frame, which means Felt was not forced to design a frame around a certain envelope, and sacrifice braking performance to fit a certain aero package. Both projects were optimized to achieve the ideal balance. The same philosophy holds true with all other integrated features including the VR Seatpost and Calpac nutrition system. Read to learn more about Felt s Aero Brake System in the Aero Brake white papers.
Comparative Test Results To measure the gains of Felt s new triathlon Superbike, the engineering team performed wind-tunnel tests to compare the aerodynamic performance of the IA against the DA time trial bike as well as several key competitor bikes including the Specialized Shiv and Cervelo P5. To most accurately simulate Ironman-type triathlon conditions (lower speeds compared to shorter road time trials; and generally windier conditions), more emphasis was placed on high yaw angles rather than low yaw angles. 281.2 Time Saved Over Baseline DA (seconds) 186.2 Aerobar Integration A thin and aerodynamic triathlon basebar is seamlessly integrated into a low-profile stem. All Aspect Tubing Down tube and seat tube profile and cross section are engineered not only to reduce drag across common yaw angles, but generate lift to reduce the effort required to accelerate and maintain speed. BatPac Internal storage for Di2 Battery. Aerodynamic Bottom Bracket Area A BB30 is used for its narrower section, which helps to reduce drag coefficients. CalPac IA Feature Glossary Horizontal conformal carriage for energy gels, energy bars and race supplements. Dagger Seat stays Near-horizontal seat stay design improves aerodynamics by reducing wind drag. The design also improves comfort with its leaf-spring effect and boosts lateral stiffness with its small rear triangle surface area. Integrated Fork Design An integrated fork permits a narrower head tube section, which minimizes drag and increases aerodynamic performance. Cloaked Front Aero Brakes Aero-optimized front brake cover reduces wind drag. Cover is easy to remove for brake service. Felt IA Cervelo P5 The easiest way to interpret the wind tunnel data in real world terms is to look at the times of a specific power output over a specified distance. In this case, each of the bikes was analyzed at 230 watts over 112 miles (the length of an Ironman bike course). As you can see below, the IA saved 4:40 over the DA. That result bested the P5 by 3:06 and the Shiv by 22 seconds. Wind Tunnel Comparison Data 22.8 Specialized Shiv Cloaked Rear Brake Rear brake is strategically positioned on underside of chainstays for optimal aerodynamic efficiency. Removable cover makes the brakes easy to service. Cloaked Cable Routing Fully-integrated drivetrain cables or electronic wiring creates optimized aerodynamics, component performance and serviceability. Internalock Seat Post Binder Bolt An intelligent, internal seatpost clamping system prevents over-torque of clamping forces and is elegantly integrated as to not obstruct aerodynamics and aesthetics. Aero Head Tube Aggressively shaped aero head tube allows the wind-generated drag forces to be greatly reduced. Sub-Stance Front Derailleur Mount New front derailleur mount improves all front derailleur performance, mechanical or electronic, especially when shifting from the small chain ring to the large. CDA (drag coefficient x area) Yaw (angle of wind force) VariMount SeatPost* Uniquely designed clamp provides secure angular saddle position that allows a maximum range of adjustment with a single bolt. VR Seatpost Compliance translates to comfort without a tangible compromise in performance. The design of the VR seatpost aids in vibration reduction to achieve desired damping. Head Tube Angle Seat Tube Angle Top Tube Horizontal Head Tube Length Bottom Bracket Drop Rear Center Front Center Wheelbase Standover Height Seat Post Offset Reach Trail Geometry Chart XS 71.5 79.5 468 67.5 5 961 744 50 381 60.3 S 71.5 79 486 96 589 978 776 50 389 60.3 M 78.5 510 111 602 991 790 45 405 62.5 L 78 541 136 630 1020 819 54 426 62.5 XL 77.5 573 163 659 1049 840 54 447 62.5 AE RO * VariMount (VM) seatpost is offered as an alternative to VR seatpost on some IA models