2014 Felt IA - Felt Bicycles

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.
‘90
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.
‘00
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.
‘03
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.
‘06
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.
2012: American Kristin
Armstrong rode the Felt
DA to an Olympic gold
medal at the time trial
race in London.
S 22
2013: The all-new Felt
IA is released as part of
Felt’s 2014 lineup.
‘10
‘14
IA
DA
DA
B2
Paula Newby Frasier -1989
1989 2013 - Andy Böcherer
DA
A Triathlon Superbike
VR Seatpost
Vibration Reduction seatpost provides
excellent shock absorption with the help of
3T’s Diff-LockTM comfort module.
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.
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.
AERO
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-LockTM Seat Clamp
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.
2
9
11
12
3
10
8
14
Internalock Seatpost Binder Bolt
5
The best method of optimizing and
dispersing clamping force on an
aerodynamic seatpost. Seatpost adjustments
remain secure. Easy to remove and travel
with.
1
6
4
13
7
Aerodynamics
AeroPac Cover
The storage reservoir integrated into the
IA top tube features a silicone cover to
securely contain nutrition as well as retain
aerodynamics by blending into the surface
of the frame. The cover allows on-the-fly
and easy access to stored goods.
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.
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.
CalPac
CalPac: Horizontal compartment for energy
gels, bars and race supplements.
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
IA Feature Glossary
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.
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
Time Saved Over Baseline DA (seconds)
Internal storage for Di2 Battery.
Aerodynamic Bottom Bracket Area
A BB30 is used for its narrower section, which helps to reduce drag coefficients.
281.2
CalPac
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.
186.2
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.
22.8
Cervelo P5
Felt IA
Specialized Shiv
Click here for Felt 2014 IA Aerodynamic Test Procedures Appendix
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.
2014 Felt IA Wind Tunnel Comparison
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.
VariMount SeatPost*
Uniquely designed clamp provides secure angular saddle position that allows a maximum range of adjustment with a single bolt.
DA Baseline
Cervelo P5
Cervelo P5*
Felt IA
CDA Drag Coefficient x Area
Sepcialized Shiv
700
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.
600
Geometry Chart
500
400
300
Yaw (angle of wind force)
-20.0 -17.5 -15.0 -12.5 -10.0 -7.5
-5.0
-2.5
500
0.0
*Alternative configuration with stack height lower than Felt and Specialized Bicycles
2.5
5.0
7.5 10.0 12.5 15.0 17.5 20.0
XS
S
M
L
XL
Head Tube Angle
71.5
71.5
72
72
72
Seat Tube Angle
79.5
79
78.5
78
77.5
Top Tube Horizontal
468
486
510
541
573
Head Tube Length
67.5
96
111
136
163
Bottom Bracket Drop
72
72
72
72
72
Rear Center
400
400
400
400
400
Front Center
572
589
602
630
659
Wheelbase
961
978
991
1020
1049
Standover Height
744
776
790
819
840
Seat Post Offset
50
50
45
54
54
Reach
381
389
405
426
447
Trail
60.3
60.3
62.5
62.5
62.5
AERO
* VariMount (VM) seatpost is offered as an
alternative to VR seatpost on some IA models