a special PDF produced by Specialized

The Facts on
Specialized FACT
(Functional Advanced Composite Technology)
Regardless of the experience a rider is seeking, Specialized's purpose is to make bikes
and equipment that enable all types of
cyclists to get more enjoyment from their
time on a bike.
More than just composite materials, FACT
allows us to make the best riding bikes and
equipment on the market for any experience.
FACT is a proprietary term that distinguishes our advanced composites development
and fabrication process, one that always
starts with the demands of the experience,
and results in bikes and equipment with
proven performance benefits, including:
Increased efficiency
Flawless handling
Unsurpassed fatigue-reduction
Incredibly low-weight
(left) Liam Killeen, raising his arms in victory at the 2006 Sea Otter
Classic in Monterey, California Bike: S-Works Epic Carbon
(On Cover)
Levi Leipheimer charges his way to win the 2006 Dauphine Libre
Bike: S-Works Tarmac SL
A WORD ABOUT FACT FROM SPECIALIZED'S
DIRECTOR OF ENGINEERING, MARK SCHROEDER
At Specialized, our vision is to be the best cycling brand in the
world. Among other things, that means creating bikes and equipment that help all riders enjoy their time on a bike more. Because
the entire company is filled with demanding cyclists—including
my entire engineering team — creating bikes that have an outstanding ride means everything.
Whether used in frames, forks or equipment, FACT is a proprietary term that distinguishes our advanced composites development, fabrication and testing process, FACT starts with the
demands of the experience, and results in bikes and equipment
with proven performance benefits that include increased efficiency,
unsurpassed fatigue reduction, incredibly low weight and flawless
handling.
Most critically, FACT enables us to consider the performance of a
bike as a whole. We never focus on specific attributes like weight
or stiffness without considering the effect on the overall package.
By considering all attributes of a bike and how they interact, we're
able to fine-tune our FACT composites for any experience a rider
is looking to have.
A perfect example of the way we deploy FACT is evident in our
new S-Works Roubaix SL. While maintaining the overall ride quality, the FACT process of testing and refining has allowed us to
take vertical compliance a serious step further, making the new
S-Works Roubaix SL the most compliant ever. The difference in ride
comfort between the S-Works Roubaix SL and the next closest
competitor is greater than the difference between riding a 23C
tire at 90 versus 120 PSI. This benefit is realized with zero sacrifice in performance. We set out to achieve an industry leading
level of compliance while maintaining light weight and stiffness,
and we delivered on that promise. By far, it’s the most fatiguereducing and compliant performance road bike available.
world's foremost testing facilities in our Morgan Hill, California
headquarters. Our staff of engineers and technicians monitor
countless hours of bending, breaking and smashing to ensure that
every frame and component is more than up to the task. In addition to our in-house test staff, we also involve the world's leading
athletes in our field testing processes. We ask all of our athletes
to provide critical feedback that we can compare to our lab testing results. All of our testing adds to the quality and safety of our
bikes and equipment and helps them to match the experience
that any type of cyclist is looking to have.
Every Specialized product, carbon or otherwise, meets or exceeds
safety standards from around the world. We take this very seriously, and our frames and forks are tested for ultimate strength,
fatigue, impact strength, plus an array of international safety
tests. We test multiple quantities of every frame, fork, or component we make in every size offered. Sure, it's expensive, but it's
something that helps me sleep at night.
We'll continue to improve every design we make and will always
be on the lookout for innovative ways to achieve lower weight,
higher torsional or bottom bracket rigidity, or greater vertical
compliance — but never with a single-minded focus on one
element. To do so would come at the expense of the other frame
design parameters, and at the expense of the ride quality. And
that's not our goal.
“We're here to make the best bikes,
and we can only do that by considering
and balancing all the needs of the riders
who demand the best.”
And that, my fellow riders, is innovation.
“Our new S-Works Roubaix SL with FACT Az1
construction is far more compliant than any
other we have tested, yet still lighter and stiffer
than most competing designs.”
Mark Schroeder
Director of Engineering,
Specialized Bicycles
Safety is our top priority and our dedication to creating bikes with
the best overall performance for any given experience means that
we must also create bikes that are safe. We have one of the
The Specialized Engineering and R&D Team
(from left to right): Luc Callahan, Gui LeFebvre,
Mark Schroeder, Kyle Chubbuck, Joe Cahoon,
Sam Pickman, Andy Jacques-Maynes.
FACT WHITE PAPER | 1
UNDERSTANDING THE RIDE
Acute Rider Insight is the First Step in the Creation of any FACT Chassis or Component.
With any Specialized bike or piece of equipment — regardless
of price or intended rider experience — the materials we use,
the design we select, and the manufacturing process we
employ are all chosen in careful consideration of one another.
This integration of development ensures a harmoniously
balanced, completely integrated, experience-optimized piece
of equipment…one that has been perfectly designed and
manufactured for its intended application.
Different types of riding demand different attributes from a
chassis or component. Once our design and engineering team
understand the experience that a particular bike is being
created to fulfill, we prioritize the following attributes
depending on the specific product that is being developed:
• Lateral and Torsional Rigidity: Excellent bottom bracket
stiffness and torsional rigidity enhance efficiency, responsiveness and handling.
• Appropriate Strength: Different types of riding have different strength requirements. FACT takes these into account
and creates strength targets that surpass industry standards
to ensure that the frame or component is more than up to
the task.
• Vertical Compliance: FACT frames and forks feature superior vertical compliance — fatigue-fighting compliance that's
measurable.
• Weight: Less is obviously more, but only if safety and ride
quality standards are satisfied.
Heinrich Haussler on Roubaix SL while racing the 2006 Tour of Flanders
The development of any FACT chassis or component always starts with the demands of the experience that it is being designed for, then moves into a wholly integrated process involving:
Design and engineering
Selection and manipulation of appropriate materials
Selection of a Manufacturing Method: At Specialized
we use only Az1 Sequentially Cured Monocoque and
Triple Monocoque (more on that later)
Testing and revision of the Lay-up Schedule
Development (LSD)
Performance testing in both our lab and the field
Once an original version of a chassis or component is in the field, we continue to test,
with each round of testing resulting in further fine-tuning and revision of the product.
This testing loop continues until the optimal result has been achieved.
FACT WHITE PAPER | 3
FACT DESIGN AND ENGINEERING
The S-Works Roubaix SL seatstay employs an engineered shape and Zertz vibration
damping inserts to allow for more vertical compliance than taking 30 psi out of a 23c tire.
A collaborative process that results in frames and components that look as good as they ride.
Beyond just visual style, the shape of a carbon frame or
component has a huge impact on how it will perform.
After concept drawings are created by our industrial
design team, the engineered shape of any carbon chassis
or component is developed by our engineering team
using a variety of digital design tools that enable them to
optimize the design around experience-critical attributes,
such as stiffness, compliance and weight.
In the case of frames like our Tarmac or Roubaix models,
tube shapes are initially optimized for stiffness and
strength from theoretical calculations using Pro/
Mechanica FEA (Finite Element Analysis) modeling software on our workstations in Morgan Hill, California. Tube
shapes are determined according to function (needs of
the specific frame area(s)), aesthetics (making them look
good without sacrificing their functional characteristics),
and to ensure the most efficient use of our composite
mold and lay-up resources. The advanced surfacing
capabilities in Pro/Engineer allow the use of organic
shapes. Just run your hand along the top tube of a
Roubaix to see what we're talking about; you can feel the
tube change shape as you move your hand along its
entire length.
APPROPRIATE MATERIALS SELECTION
Why we use what we use in every FACT chassis or component.
Different carbon processing methods result in carbon fiber
with different mechanical properties. When considering
carbon for a given application, our engineers primarily consider two factors: stiffness and strength. Stiffness is better
known as “Modulus of Elasticity” (E), measured in Giga
Pascals (Gpa). Strength, or more accurately “Tensile
Strength” (Y), is measured in Mega Pascals. Both are considered in any carbon project, but to varying degrees; road
projects that require maximum rigidity and have lower peak
loads are often more concerned with Modulus of Elasticity
or stiffness, while mountain projects tend towards tensile
strength to handle the higher peak loads encountered in
off-road riding.
To make it easier to talk about our materials we've developed a shorthand naming system based on the intended
use of a product. For all road applications, E-Series carbon
is used because 'E' is the engineering term for modulus of
elasticity. Similarly, Y-Series carbon is used for all off-road
applications since 'Y' is shorthand for Tensile Strength. Got it?
By using these measurable and observable characteristics
to define the material selection, we've made it easy to see
and understand why we use what we use in every FACT
chassis or component. “There's no pixie dust or hype in our
materials, just good engineering sense,” says Specialized's
Director of Engineering Mark Schroeder.
MATERIALS USED IN SPECIALIZED COMPOSITE FRAMES
Frame Material
Modulus (GPa)
Tensile
Strength (MPa)
Outer Woven
Layer
390
4610
Uni
S-Works Tarmac
294
5490
Uni
Roubaix Pro/Comp
285
5790
3k
Ruby Pro
285
5790
Uni
All composite MTB frames
285
5790
Uni
HIGH MODULUS
S-Works Tarmac SL, S-Works Roubaix SL
INTERMEDIATE MODULUS
STANDARD MODULUS
Tarmac Pro/Comp
230
4900
12k
Roubaix Elite
240
4900
3k
Ruby Elite / Comp
240
4900
12k
Modulae and strength of the primary Specialized frame building materials.
FACT WHITE PAPER | 5
APPROPRIATE MATERIALS SELECTION CONTINUED
To help create a basis for comparison of various fabrication processes, we've developed a ranking system for FACT
and other manufactures' composites. This Food Chain ranking system considers a number of factors including: material
strength and stiffness, manufacturing method, and the top or finish layer of carbon used.
THE FACT FOOD CHAIN
A ranking for carbon that takes more than just weight into account.
ROAD BIKES
Designator
Primary Material
Fabrication
Finish Layer
Specialized Models
10R
E390
Az1
Uni
SW Tarmac SL, SW Roubaix SL
8r
E294
Triple Monocoque
Uni
SW Tarmac
7r
E285
Triple Monocoque
Woven (3 or 12k)
Roubaix Pro & Expert; Ruby Pro
6r
E240
Triple Monocoque
Woven (3 or 12k)
Tarmac, Roubaix Comp & Elite,
5r
E value = 2000-240
Tube/Lug/Monocoque
Woven or Wound
4r
E value = 2000-240
Tube/Lug/Monocoque
Woven or Wound
3r
E value = 2000-240
Tube/Lug/Monocoque
Woven or Wound
Ruby Expert & Comp
OFF-ROAD BIKES
Designator
Primary Material
Fabrication
Finish Layer
Specialized Models
10R
y579
Az1
Uni
SW Epic, Stumpjumper, HT
Comparative table of composite frame building materials and processes.
UNI SHEETS OF PREPREG THAT ARE USED IN OUR FRAMES:
Though high-modulus carbon is good for strength and stiffness, it
tends to become more brittle (less strong) as it gets stiffer (see
charts). In general, you wouldn’t want to build a whole frame out
of high-modulus material, so we hybridize (mix) our high-modulus
carbon with a number of other materials and in varying modulae
(stiffness ratings), to make frames as light as possible without
sacrificing strength or durability. The general idea is to put the
higher-strength material where the loads are, and to save as much
weight as possible everywhere else with stiffer high-modulus
material.
True High Modulus
Modulus is an engineering term for fiber stiffness. The stuff we use
is rated at 390 GPa (gigapascals), or 57Mpsi (millions of pounds
per square inch). That’s about 70% stiffer than the standard aerospace-grade material most carbon bicycle frames use.
Intermediate Modulus
Intermediate Modulus carbon fiber is used to maximize strength
and keep weight low in the highly stressed parts of the frame, like
the top and down tubes. Because of its relatively high modulus and
superior strength, this material is a good all-around workhorse for
premium composite frames.
Standard Modulus
Standard Modulus is aerospace-grade carbon fiber. It’s used in
conjunction with the other materials for improved impact strength
in specific areas. Note, some companies call any aerospace-grade
material “high modulus”. This is technically incorrect and leads to
confusion. When in doubt, ask.
(opposite page)
Ned Overend won the first World Championships riding a Carbon S-Works Epic Ultimate
in 1990. 16 years later, he’s still tearing’ it up! Bike: S-Works Stumpjumper FSR Carbon
UNI? WOVEN? WHICH IS BEST? THEY BOTH NEED EACH OTHER.
Once raw carbon is processed into carbon fiber, it is made into “sheets.” These sheets are either “woven,” creating the crosshatched look that is most often associated with carbon (and usually used only as a final protective layer) or “uni-directional,” with all the fibers running in the same direction. Uni-directional sheets are typically far lighter and are layered together
in different orientations to achieve specific strength/stiffness. Because they are incredibly protective, but heavier, woven
sheets are used as a final wrap on many FACT frames and components. Once the final frame or component is layered, these
sheets are “wetted out” with a resin that cures when heated. It is this heating and curing process that ultimately turns the
pliable textile sheet into a lightweight, high-performance component or frame.
UNI SHEET
WOVEN SHEET
Unidirectional (left) and woven (right) material samples. Both are shown with epoxy resin pre-impregnated (prepreg).
FACT WHITE PAPER | 7
FABRICATION
OF FACT
MONOCOQUES MAKE BETTER BIKES.
With the exception of small parts like our carbon dropouts, every FACT frame, fork or piece of equipment we create
utilizes one of two monocoque manufacturing methods. We never consider “off-the-shelf” options like filament-wound tubes and never
utilize what we consider to be outmoded tube-and-lug construction methods. In conjunction with heavily refined Lay-Up Schedule
Design and continual testing, we are always able to determine the optimal monocoque construction method for a particular project.
Why are monocoque methods better? By utilizing monocoque frame construction techniques, we are able to work exclusively with seamless structures and that eliminates the need for
the bonding of lugs and tubes. This has a number of advantages:
Stronger and smoother: There are no stress concentrations like
those caused by lugs, making our FACT monocoques stronger and
more able to distribute forces across an entire structure.
More reliable: There is no chance for a failure at the bonding point
due to poor glue application or uneven glue thickness around the
bond.
Better alignment: Monocoque frames leave the mold with a consistently higher level of quality including a more accurate alignment. That makes monocoque bikes handle better.
Less weight: By eliminating the need for overlapping seams, the
amount of material needed to create a frame is reduced, so the
overall construct is lighter.
The downside to monocoque construction? It's expensive and
highly labor intensive. Yet it is the method that lets us make the
best use of our experience in customizing the ride quality and handling characteristics for each frame and keeping them consistent
regardless of their size. Sure monocoques are more expensive, but
because we're committed to producing the best frames available
there's just no other way to construct a carbon frame.
FACT CARBON
FIBER
MANUFACTURING
EXPLAINED
A carbon monocoque front triangle
ready for bladder
molding. In this
stage, the carbon is
still soft and pliable.
Step-by-step directions for baking a FACT frame.
Step 1: Creation of Custom Steel Tooling
After curing, the
monocoque is now
ready to be assembled.
A custom-made steel mold which defines the exact outside
shape and surfaces (the part of the frame you can see) must
first be made. Depending on the part it's being created for, a
steel mold like that used for the main triangle of a Roubaix
takes 8 to 12 weeks to make, That's because it's a big chunk of
steel that is entirely hand finished, weighs a few hundred
pounds and has to be accurate to within a few thousandths of
an inch in every aspect. A finished frame or part comes out
weighing just a tiny fraction of the tool. Assuming the mold is
made right, the finished part will have the same level of accuracy as the mold.
Step 2: More Than A Balloon
Flexible sheets and pieces of carbon that have been impregnated with epoxy are assembled into the shape of a frame,
fork or part according to an exhaustively revised Lay-Up
Schedule Design. An air bladder made of pressure-resistant
(you'll see why in a minute) nylon is placed throughout the
inside of the flexible composite lay-up structure. Its function
is to internally pressurize the composite material in the lay-up
against the tooling surface to eliminate internal voids in the
composite structure. A frame, or other composite part at this
phase of the fabrication process, feels like a really light and
soft black rag or sponge. Not for long, though.
After assembly, each
frame is checked for
perfect alignment.
Step 4: Cool It
Still pliable, the entire prepreg assembly including the nylon
bladder is placed inside its big steel mold (by the way, there's
a different mold for each size). Next, the multi-piece mold is
closed and locked down. Finally, the nylon bladders are connected to pressurized air fittings.
Step 3: Not So Easy-Bake
The closed mold moves on a conveyor into an electric oven
where the mold's temperature is raised to 155° C (that's 311°F,
or if you really want to be scientific, 428.1 K.) The high temperature allows the epoxy in the prepreg to become liquid
and spread uniformly in the composite lay-up, To help things
along, the bladders inside the prepreg assembly are pressurized to 150 psi. This mixing of epoxy in the carbon fabric is
called “wet out” and it's critical to the integrity of the molded
structure. Too little pressure in the bladder and the composite
won't wet out effectively, leaving high-epoxy areas that add
useless weight, and low-epoxy areas that weaken the structure. Too much pressure, and the epoxy gets squeezed out of
the composite altogether. Correct wet out pressure forces
between 4% and 8% of the resin out of the prepreg.
Note: some manufacturers use a process called RTM (for Resin Transfer
Molding). In RTM, the composite is laid into the mold dry,(which lowers labor
costs) and epoxy is forced in under pressure. Assuming the processes are
used correctly (optimal wet out), there's no structural difference between an
RTM part and one made from prepreg. Generally, RTM is more successful with
simpler shapes (like plates or links or lugs) and less successful with more
complex shapes (like frames or forks). In terms of the performance of the finished product, there is no particular advantage to RTM versus prepreg.
The mold stays at this temperature for about 30 minutes
depending on its size (being on the larger side, a Tarmac mold
can take up to 45 minutes to heat.) Now the mold must cool.
Due to the size and mass of the steel tooling, this takes another 20 to 30 minutes depending again on size. Once the frame
inside the mold has cooled enough, the epoxy is cured and
cannot be changed. If there is even a minor defect or trouble
with alignment, the entire frame must be scrapped.
Composite structures made with an epoxy matrix that stays
the same once it's cured are called thermoset. Structures that
are made with a different matrix that can be heated and
changed over and over are called thermoplastic. Old-timers in
the bike business may remember when some people thought
thermoplastics were superior materials for making bicycle
frames and components. Without getting into the physics of
it too much, those people were wrong. And nowadays, mostly out of business.
Step 5: Fini!
Finally, the operator can remove the cured composite structure from the mold and the structure is ready for assembly
(see next page.)
Note: To the greatest extent possible all bladders and other nonstructural fitting are removed from our frames as part of the finishing process. Elimination
of all non-structural material is one reason Specialized frames can be both
lighter and stiffer than the competition's.
FACT WHITE PAPER | 9
CONSTRUCTION METHODS
A FRAME'S NOT FINISHED
UNTIL IT'S ASSEMBLED.
Once the individual monocoques for a FACT frame are molded, they
must be assembled into a finished construct. We could use any number
of different methods for accomplishing this, but, after years of
refining and thousands of frames, we've settled on two ultraadvanced, super-precise methods: Az1 Sequentially Cured
Monocoque and Triple Monocoque. Maybe we should explain.
Az1 Sequentially Cured Monocoque Construction Explained
Az1 (pronounced “as one”) made its debut in our product line in the
2006 model year, and we've found that it is unsurpassed by any other
composite manufacturing method for strength-to-weight and
stiffness-to-weight.
S-Works Roubaix SL Triple Sequentially
Cured Monocoque Frame
Discrete 100% optimized carbon monocoque sections are created
and cured, allowing a substantial reduction in material and weight by
keeping the sections smaller. These monocoque sections are then
precision mitered, chemically bonded, and then undergo a proprietary
lay-up process to unify the monocoques into a single piece. A proprietary mold and chemical expansion process then ensures perfect
compaction and zero voids.
Finally, the mold is heated, and the secondary lay-up is sequentially
cured, and the results are the most optimized carbon frames in the
world.
Advantages:
Disadvantages:
The lightest and strongest construction
method used to create a carbon frame.
Extremely time and labor intensive.
Frames that use our proprietary Az1 Sequentially Cured Monocoque
process include: Tarmac SL, Roubaix SL, all off-road frames.
Triple Monocoque Construction Explained
Triple Monocoque: a balanced approach to frame assembly that
minimizes seams and redundant materials. In triple monocoque
construction, the main triangle, chainstays, and seatstays are each
created as a single monocoque structure, and then joined together at
the dropouts, bottom bracket, and seatstay/seat tube junction using
aerospace adhesives and a final carbon wrap.
Roubaix Triple Monocoque frame
Advantages:
Stress concentrations are reduced and less
material can be used. Frames are lighter,
more optimized for stiffness and strength,
and perfectly aligned.
Disadvantages:
Expensive tooling and set-up costs, more
labor intensive.
Frames that use our proprietary Triple Monocoque Construction
process include: Tarmac Expert, Tarmac Comp, Tarmac Elite, Roubaix
Expert, Roubaix Comp, Roubaix Elite, Ruby Pro, Ruby Expert, Ruby
Comp.
LSD: An example
This outlines the lay up schedule for a single frame tube. This particular example
is a downtube from a 2004 model (we’re not allowed to reveal this kind of detail
on current models).
Down Tube
Position
Order
Fiber
Width
×
Length q'ty
Note
-70 -60 -50 -40 -30 -20 -10 0
MATERIAL
1
0
Mandrel
2
45IM600
15
×
66
1
3
0 IM600
15
×
66
1
4
0 IM600
8
×
66
1
5
45IM600
15
×
66
1
6
45IM600
15
×
66
1
7
45IM600
15
×
66
1
8
0HR40
3
×
60
4
9
cutting
0IM600
3
×
15
1
CW3110
15
×
48
1
GF woven
1.5
×
40
1
Nylon tube
0.08
SEAM LOCATION
SIZE
WEAVE
ORIENTATION
4cm
7.5FP
6FP
5.5FP
8cm
10
11
× 120×125
2
LAY-UP SCHEDULE DEVELOPMENT (LSD)
The anisotropic (directional-specific) nature of advanced
composite materials allows Specialized engineers to use
weaves and ply designs to create frames or components
that are stiffer in one or more axes, while remaining more
compliant in others. Engineers can also “tune” the weave
structure, ply angles, fiber alignment and lay-up patterns of
or component to optimize performance
a particular frameQF10-50-4
characteristics for its intended use. The resulting pattern of
directional layers of composite material fibers (in this case,
carbon) is called a lay-up. The overall protocol we use at
Specialized for developing lay-ups is called Lay-up
Schedule Development, or LSD (yes, LSD).
MANUFACTURING THE LAY-UP
The major lay-up in the top tube and down tube of our
frames is composed of multiple layers of uni-directional
carbon sheets in different angle orientations. Some fibers
run fore/aft. These are referred to as “zero” fibers. These
fibers give the frame a lot of strength for in-line impacts
and loads and makes the frame good at resisting bending
or axial loads. Some fibers run at angles of plus or minus
45°, 30° or 22.5°. These fibers give the frame its torsional
(twisting) stiffness.
Each frame has a detailed laminate schedule. The tubes
have 5 or 6 main plies but there are nearly 200 pieces of
carbon fiber in a frame's lay-up schedule (that's why LSD is
such an involved process.) Placement of smaller pieces of
carbon fiber at tube junctions enables the joints to handle
loads better and minimizes overall weight. From the largest
to the smallest, every sheet or piece of carbon is cut and
placed by hand, making worker training and quality control
a top priority. Once completely assembled, the carbon fiber
lay-up is called a prepreg assembly. This assembly is loose
and flexible and ready to be placed in a mold and cured.
FACT WHITE PAPER | 11
CONSTRUCTION METHODS
Raw Tarmac frame with engineers’
notes on how it performed in testing.
LAY-UP SCHEDULE DEVELOPMENT (CON’T)
LSD Testing, Tuning, and More Testing
Initial
frame prototypes are lab-tested to achieve required
strength at all junctions and load points. The lay-up is also
revised to achieve required strength and stiffness. After initial
structural testing, we start ride testing in a range of sizes, with
a number of riders to get their “perceived” feedback. Having
ridden hundreds of frames in their lives, these riders can tell us
how a frame climbs, sprints, corners and “feels” overall.
We measure the sample frames in the lab for stiffness and
compare riders' perceptions to lab data. Weight is easy to
measure, all you need is a scale. Stiffness is more difficult to
measure, but can be tested in a number of ways, including bottom bracket deflection under simulated pedaling loads, overall
torsion (twisting) from head tube to rear dropouts and vertical
compliance. We also measure how much vibration is transmitted through the frame; subtract that number from how much
vibration we put into it in the first place, and we can measure
vibration isolation (also called attenuation or damping).
Then comes the “tuning” process: multiple iterations of the
frame's lay-up are generated to balance stiffness, vibration
damping, perceived road feel, and of course, overall strength.
Even with our high-powered testing software and hours of
road testing with a cadre of the world's best riders, it takes a
minimum of five iterations to optimize all parameters, and sometimes far more. With the final lay-up determined, we conduct a
number of destructive lab tests (with multiple samples for each
size) to verify that the lay-up is stable and predictable. For
more details on our testing methods and competitive analysis,
see pages 15-20
TESTING, TESTING…
FACT Performance That
You Can Measure
There are a number of proprietary (and confidential) tools and protocols we use to
compare our frames to the competition’s, but there are two universally accepted comparisons we can talk about: weight & stiffness.
Overall, Specialized composite
frames are measurably lighter,
laterally and torsionally stiffer, and
more vertically compliant, without
sacrificing appropriate strength and
toughness characteristics for the
most demanding riders in the world.
We test and benchmark the best
performers out there (our own bikes,
and those from other brands), then
set goals to exceed all other bikes in
the category.
2. BB Pedal Stiffness Test. Again, a higher
number is better. The stiffer the structure
is to the rider’s pedaling forces, the faster
the frame will respond to rider acceleration.
Obviously, there’s only one weight test:
we take a finished 56cm or equivalent
frame and weigh it. (All weights include
paint, Zertz inserts (if used) and equivalent
hardware.
3. Vertical Compliance Test. A measure of
how a frame responds to loads applied in
a vertical plane, which correlates to ride
comfort. Compliance is the inverse of
stiffness – or, more simply, as a frame gets
more compliant, it becomes less stiff.
A higher number represents more compliance. It’s important to note that this is an
isolated vertical compliance test, and is
independent of torsional or BB stiffness.
While there are a number of commonly
accepted stiffness measurements, three
are most useful for comparisons purposes:
1. Torsion Test. This is overall frame torsion measurement from head tube to rear
dropouts. The higher number indicates
the frame is stiffer. This measurement is a
good indicator of how well a frame will
handle in turns and how stable it’ll be at
high speed.
In addition to our test riders actually
riding hundreds of thousands of
miles per year, we also design and
perform measurable, repeatable
tests in our state-of-the-art lab. Here
we can compare different revisions
of our frames during the development cycle, continually tweaking it
until we have optimized the frame.
Finally, stiffness values are corrected to
compensate for the weight of the frame
(specific stiffness). This makes for a better
comparison between light and heavy
frames.
DATA ANALYSIS
The following data are comparative results based
on 23 frames and framesets tested by Specialized engineers since 2004.
System Weight (Frame, Fork, Crankset/BB)
SYSTEM WEIGHT (Frame, Fork, Crankset/BB)
2710
2682
2622
2548
2548
2524
2451
2446
2415
2395
2391
2376
2347
2344
2310
2301
2282
2263
2244
2244
2178
2148
2054
2041
2000
1915
W e i g h t (G r am s )
2500
2522
HEAVIEST
2498
LIGHTEST
1500
1000
500
Sp ec
ializ
ed S
-Wo
S p ec
r ks T
ializ
arm
ed S
ac S
-Wo
L
r ks R
oub
aix S
L
Cerv
elo
R3
Sco
tt C
Gian
R1
t TC
RA
dv a
nced
Sev
en E
lium
Loo
k 58
Calf
5
ee D
rago
nfly*
Gian
t TC
R
Orb
e
a
Orc
Can
a
non
dale
Syn
apse
Cerv
elo
S p ec
Solo
ializ
ist
ed R
Sp ec
o
u
b
ializ
a
i
x
ed S
Pr o
-Wo
r ks T
a
r
m
Trek
ac
Mad
one
590
0
Orb
ea O
Trek
pa l
Mad
one
Spe
SL 5
cializ
.9
ed T
arm
ac P
ro
Kest
ral E
voke
L
itesp
Sp e
cializ
e ed
Vort
ed S
ex*
-Wo
r ks T
arm
ac E
5
Loo
k 55
Le m
5
ond
Vict
o
i
r e*
Can
non
dale
6-13
*
Sero
tta O
ttro
tt*
Tim
e VX
*
Loo
k Kg
486
0
Model
* Assumed fork weight of 380 grams
Notes:
Total weights reflect Specialized S-Works Carbon Crankset/BB for Specialized Roubaix SL, Tarmac SL
All other frames assume FSA K-Force MegaEXO carbon crankset/BB
FACT WHITE PAPER | 13
TESTING METHODS
VERTICAL COMPLIANCE
Vertical Compliance Testing
In testing vertical compliance, each
frame is fixed at the head tube and rear
dropouts, and a series of compression
weights are applied straight down on
the seatpost clamp. For consistency, the
distance between the BB center and
the top of the seatpost is constant on
all frames tested. The deflection measures the ability of the frame and seatpost combination to absorb shock in a
vertical plane.
Specialized FACT Carbon frame
undergoing vertical compliance
testing in the Specialized test lab.
Tire Pressure Vertical Compliance
TIRE PRESSURE VERTICAL COMPLIANCE
MOST COMPLIANT
LEAST COMPLIANT
9.35
10.55
10.0
9.8
11
4
V e r t i c al C o m p l i an c e ( i n /l b f * 1 0 )
15.0
5.0
120
110
100
90
0.0
Tire Pressure (psi)
A Perspective on Vertical Compliance:
To give a perspective on the relative ride quality value of our vertical compliance
testing, we have shown the results of a comparable test on a race-quality rear
tire/wheel combination tested at a usable range of tire pressures, between 90
and 120 psi.
The important point is to note from the graph is that the total range of vertical
compliance between 90 and 120-psi is smaller than the vertical compliance difference we measured between many comparable frame/post systems. Or, more
simply: the difference in compliance between our S-Works Roubaix SL and our
Tarmac SL is almost as significant as the difference between running your tires
at 90psi and 120-psi.
Also, we can safely say that letting air out of your tires won't address a frame
design that is overly stiff. If a frame is too stiff vertically, there simply isn't enough
range of compliance available from tire pressure to balance the ride.
THE BOTTOM LINE: greater vertical compliance improves rider comfort and
reduces fatigue, which in turn improves efficiency and rider performance.
FACT WHITE PAPER | 15
TESTING METHODS CONTINUED
TORSIONAL
STIFFNESS
(lbs/in
Kg)
Torsional Stiffness
(lbs/
/in
per Kg
gper
)
STIFFEST
LEAST STIFF
88.0
90.0
80.0
29.2
31.0
33.0
33.3
34.1
35.7
39.9
41.9
42.2
42.4
44.8
45.0
46.0
46.5
46.9
48.4
42.7
37.0
30.7
20.0
40.2
30.0
50.5
40.0
52.4
50.0
54.9
54.9
60.0
67.1
67.8
L b s /i n p e r K g
70.0
10.0
Sco
tt C
Wor
R1
ks R
oub
aix S
Can
L
non
dale
S p ec
Syn
ializ
apse
ed S
-Wo
r ks T
arm
Trek
ac
Mad
one
Sp ec
S
L
5
ializ
.9
ed R
oub
aix P
ro
Cerv
elo
Solo
ist
Kest
ral E
voke
Loo
Spe
k 58
ciali
5
zed
Tarm
a
c
Pro
Trek
Mad
one
590
Gian
0
t TC
RA
dv a
nced
Calf
ee D
rago
nfly
S p ec
Orb
ializ
ea O
ed S
pa l
-Wo
r ks T
arm
ac E
5
Tim
e VX
Gian
t TC
R
Can
non
dale
6-13
Orb
ea O
rca
Loo
k 55
5
Sero
tta O
ttro
tt
Le m
ond
Vict
oire
Loo
k Kg
486
Sev
en E
lium
Lites
p eed
Vort
ex
d S-
ciali
ze
Sp e
Sp e
ciali
ze
d S-
Model
Cerv
elo
R3
Wo
r ks T
arm
ac S
L
0.0
Torsional Stiffness Testing
For this test, the frame is fixed at the rear dropouts and at a single orbiting pinpoint at the middle of head tube. By weighting the bar
extending from the head tube, the test can measure the torsional deflection (twisting) along the entire length of the frame. This accounts
for the lateral deflection of the entire frame, not just a single section — it’s the most applicable to real riding conditions.
“The Tarmac SL and Roubaix SL
with their FACT crank systems are
stiffer at the pedal than any other
frame when combined with a
Campy Record Crank and BB.”
- Mark Schroeder,
Engineering Director
Bottom Bracket Stiffness Testing
(left) To test bottom bracket stiffness, each frame is fixed at the
head tube and rear dropouts, and angled slightly to simulate the
side-to-side motion of a bike during heavy sprinting loads.
Weights are applied to the bottom bracket along a simulated
crankarm at the power-stroke position, and the deflection is
measured at each level of weight.
BB STIFFNESS (lbs/in per Kg)
BB Stiffness (lbs/in per Kg)
STIFFEST
LEAST STIFF
1000.0
900.0
10 3 8. 7
1100.0
418. 1
43 5 . 0
449 . 6
47 5 . 4
48 8 . 8
5 0 7.3
5 11. 0
5 24. 4
5 3 1. 7
5 3 2. 7
5 3 3 .3
5 3 6 .7
5 44. 7
5 76 .3
6 0 4. 9
6 11. 1
6 26 . 1
6 26 . 5
6 3 2. 2
5 46 . 0
45 8 . 1
300.0
6 3 5 .4
500.0
400.0
716 . 3
700.0
600.0
720 . 3
l b s /i n p e r K g
800.0
200.0
100.0
Sco
tt CR
Can
1
non
S p ec
d
ale S
ializ
ynap
ed S
se
-Wo
r ks R
oub
aix S
L
Cerv
S p ec
elo
Solo
ializ
ed S
ist
-Wo
r ks T
arm
ac
Loo
k
Gian
58 5
t TC
Sp e
RA
ciali
dv a
zed
nced
S- W
orks
Tarm
Sp ec
ac E
ializ
5
ed R
oub
aix P
Trek
ro
Mad
one
SL 5
.9
Kest
ral E
voke
Calf
ee D
rago
nfly
Can
non
dale
6-13
Orb
ea O
Sp ec
pa l
ializ
ed T
arm
ac P
ro
Trek
Mad
one
590
0
Gian
t TC
R
Sev e
n Eli
um
Le m
ond
Vict
oire
Loo
k Kg
486
Loo
k 55
5
Sero
tta O
ttro
tt
Orb
ea O
rca
S p ec
ializ
ed S
Model
Cerv
elo
R3
-Wo
r ks T
arm
ac S
L
0.0
Graphical comparison of framebuilding materials for road (stiffness)
and offroad (strength) usage.
FACT WHITE PAPER | 17
SO WHAT TESTS
ARE INDICATIVE
OR REAL-WORLD RIDING
CHARACTERISTICS?
“There are lots of tests we do for R&D
purposes, but if you're going to narrow
it down to just two main tests, they'd be
a frame torsion test, and a BB stiffness
test.” states Luc Callahan, Senior Design
Engineer at Specialized. “The overall riding
stability of any frame is best measured by
a frame torsion test. This measures the
tendency of a frame to keep the front and
rear wheels in the same vertical plane,
essentially a measure of how stiff the frame
is when you pull hard on the bars in a
sprint, or dive hard into a corner. This is the
primary test we use when testing frames,
and it's the test relied upon by Tour magazine as well.”
“Secondly, our Bottom Bracket Stiffness
test measures the twisting and bending
forces generated by an actual pedal
load,” continues Callahan, “and we apply
the load to the crankarm at the correct
angle, where the rider generates maximum
power to the cranks.” This single test
accounts for the effects of chain tension
drawing force along the chainstay, as well
as lateral deflection of the downtube,
chainstays, and seat tube. “Both tests are
significant contributors to the way a bike
rides.” agreed Callahan.
Andy Jacques-Maynes, a professional road
racer, past National Champion, and
Specialized product manager, agrees with
Callahan. “It's possible to actually feel differences in frames that test differently.
When we do a different carbon lay-up on a
frame we're developing, the differences I
can feel in stiffness and stability are reflected in the test results that the lab generates.
The results are real.”
S-WORKS FACT CARBON CRANK:
STIFFEST AND LIGHTEST SYSTEM AVAILABLE.
FACT Carbon crankset
Patented hollow arm design with
splined integrated axle
Specialized S-Works FACT Carbon Crank
A systems approach to design has yielded a fresh look at
the relationship between frame and crank. The result is a
proprietary crank that supercharges the S-Works Roubaix
SL's performance.
The Specialized S-Works FACT Carbon Crank Is:
• Amazingly Light - 177 grams lighter than Dura-Ace crank
and bottom bracket combination.
• Incredibly Efficient -surpasses all other cranks on the
market when tested for stiffness.
The FACT S-Works Carbon Crank uses a patented (US
patent #6,443,033) construction that is functionally different from traditional arm/axle configurations. The most critical design innovation is the way we utilize carbon fiber.
Typical cranks that utilize carbon must cut the fibers at the
BB axle/arm interface, which is a high-stress point where a
seam or connection is sub-optimal. Our systems approach
to design allowed us to integrate the crank and bottom
bracket shell as a system, creating a truly superior design.
Our design allows the carbon fiber used in each crank arm
to be continuously transitioned deep into the bottom
bracket, eliminating the typically independent BB axle.
What was once the axle is now a lightweight, seamless, and
hollow extension of the FACT carbon arms.
Our design has one connection point at the center of the
BB shell. By putting the carbon spline and left/right interface at the center of the bottom bracket shell, we were able
to optimize the layup of the carbon fiber. The result allows
our arms to be completely hollow, and not require the use
of alloy supports or foam core materials typically required
in carbon crank arms.
Additionally, we achieved further advantages in areas of
stiffness, thanks to the oversized FACT/Alloy 30mm axle.
Compared to typical axles, it's stiffer, lighter, and is supported by larger sealed bearings (42mm OD x 30mm ID) that
are placed in the bottom bracket.
Total Weight (Crankset, BB)
Crank Stiffness (lbs/in)
STIFFEST
LEAST STIFF
900
LIGHTEST
HEAVIEST
513.6
500.0
777
771
700
600
594
600.0
826
800
644.8
700.0
713.1
757.6
800.0
500
400.0
400
300.0
300
200.0
XO
FSA
K-Fo
r
ce M
egaE
on
Carb
ecor
d
C am
py R
Dura
Ace
Shim
a no
Spec
ialize
d
on
Carb
ecor
d
C am
py R
Dura
Ace
Shim
a no
ce M
egaE
FSA
K-Fo
r
Spec
ialize
d
XO
0
S-W
orks
100
0.0
S-W
orks
200
100.0
FACT WHITE PAPER | 19
A sampling of Specialized FACT Carbon products available: (This page) Ruby Pro Carbon, S-Works Stumpjumper FSR Carbon.
(Opposite page) top row: S-Works Barmac, Pavé SL Seat Post, Roval Classique Rapide Wheels, 2nd Row: S-Works Tarmac SL
Frameset, S-Works Road Shoe. Bottom: S-Works Roubaix SL.
FACT WHITE PAPER | 21
#1 Reigning World Cup Champion Christoph Sauser at the 2006 Specialized
Team Training Camp in South Africa. Bike S-Works Epic Carbon
Specialized Bicycles
15130 Concord Circle
Morgan Hill, California U.S.A. 95037
© 2004-2006 Specialized Bicycle Components, Inc.
www.specialized.com