WHITEPAPER
FACT CARBON
FUNCTIONAL ADVANCED COMPOSITE TECHNOLOGY
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A WORD ABOUT FACT Specialized’s vision is to be the best cycling brand in the world. We can only achieve this goal by challenging our own assumptions and constantly re-inventing our bikes and equipment. Thankfully, we have a company filled with dedicated cyclists and demanding pro athletes who never settle for good over great. Case in point: FACT. FACT (Functional Advanced Composite Technology) is a holistic approach to composite development that differentiates our frames and components from our competitors’. The FACT process—our proprietary blend of design and engineering, materials selection, manufacturing, and testing—allows 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 entire package. A perfect example of FACT at work is the new S-Works Tarmac SL3. We took nothing for granted in designing this frame from the ground up. We developed new fabrication processes, an innovative carbon layup schedule with internal rib structures specific to each frame size, new BB technology, and new molding techniques that created the smoothest and thinnest layup possible. Through this comprehensive process, we not only improved stiffness and handling, but managed to produce the lightest frame we’ve ever made and the industry’s lightest frameset module. When it comes to our composites or any other Specialized product, safety is our number one priority. We have one of the world’s foremost testing facilities in our Morgan Hill, CA, headquarters with machines that can accurately test around the clock. Our engineers and technicians perform countless hours of testing in all phases of fatigue, ultimate strength, impact strength, stiffness, and vibration, then our pro and elite field testers get their turn. We not only exceed all industry safety standards, but conduct our own proprietary tests, which are far more demanding than the industry requirements. These days, you could say everybody does carbon—Specialized just does it better.
Mark Schroeder Director of Engineering Specialized Bicycles
FACT is an acronym that stands for Functional Advanced Composite Technology, but more importantly, it represents our holistic approach to working with composites. Like any project at Specialized, FACT starts with the needs of the rider, then we apply four critical disciplines to achieve the design targets that will best serve those rider needs: design & engineering, material selection, fabrication process, and testing. What’s the result of the FACT process? Bikes and equipment that promise real-world performance benefits for the target rider.
FACT BIKES ARE IN IT TO WIN
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EPIC — REVIEWS
TARMAC SL3 — REVIEWS
“The headline is that the 2010 Epic is a better bike than we’ve ever seen.” — What Mountain Bike Magazine
“This bike makes no apologies and doesn’t need to—it’s that good.” — Philip Booth, Road Bike Action Magazine
“No pedal stroke is wasted on the climbs and no extra energy is needed to control the bike on descents thanks to an incredibly stiff front triangle, nearly perfect suspension and flawless handling.” — Bicycling Magazine
2009 Liege-Bastogne-Liege Multiple 2009 National Championships Winner Stage win and 2nd place overall, 2009 Tour de France
WINS
WINS 2009 U23 World Championship 2009 XTerra Cup Series 2009 Sea Otter XC 2009 Pro XCT Team Classification 2008 XC World Championship Bicycling Magazine Editor’s Choice Award, Best Performance XC Mountain Bike Bike Magazine Germany’s Most Innovative Bike Award 2009 International Constructors Award
ERA — REVIEWS
“The Era is easily the sweetest freakin’ bike I’ve ever ridden. I’ve been doing some epic days on it, and it’s just killer. Love, love, love it. — Selene Yeagar, contributor to Bicycling Magazine “The Era is a capable descender that truly shines on the climbs ... If you’re a female racer searching for a bike specially built to meet your competition needs, the Era is the bike you’ve been waiting for.” — Mountain Bike Action
WINS 2009 XC World Cup #6; Bromont, Canada 3x Winner 24-Hour Solo World Championship
STUMPJUMPER — REVIEWS
“The most technologically advanced cross-country hardtail race bike that we have ever had the pleasure of throwing a leg over.” “This bike doesn’t accelerate as much as it explodes.” — Both from mbaction.com
WINS 2009 Sea Otter Short Track Women’s 2009 Leadville Trail 100
ROUBAIX — REVIEWS
“Not only did this carbon bike receive higher marks for climbing and handling than most of the race bikes we tested, it also dominated the comfort category. Don’t be fooled by the word comfort, though. This is an elite racer ... already proven in europe’s grueling cobbled classics.” — Marc Peruzzi & John Bradley, Outside Magazine
WINS 2x Winner Paris-Roubaix 2008 Paris-Roubaix 2009 Paris-Roubaix
SHIV — REVIEWS
“If I could only use one word to describe the Shiv, it would have to be “fearsome”. The Shiv looked like it was irritated to be standing there stationary, displayed on a table.” - Neil Browne, Road Magazine “Riding the Shiv, I consistently had the feeling that the bike’s limits were beyond my physical abilities. The bike is designed for the fastest time trialist in the world and it shows. In the hands of Cancellara, the Shiv will cut a straight line to the top of the podium.” — Philip Booth, Road Bike Action Magazine
WINS 2009 TT World Championships 2009 Danish National TT Championships Prologue and final time trial, 2009 Tour de Suisse Stage win, 2009 Tour de France Prologue and stage win, 2009 Vuelta a Espana Stage win, 2009 Tour du Poitou Stage win, 2009 Eneco Tour
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DESIGN & ENGINEERING
FACT DEVELOPMENT PROCESS FROM EXPERIENCE PHILOSOPHY TO FINISHED PRODUCT It’s a universal truth. Different types of riding demand different qualities from a frame or component. That’s why, from day one, we design for those differences. We call them “experiences”. Before development even starts, our design and engineering teams set out to fulfill a specific rider experience with each bike. Guided by the needs of that experience (e.g. XC race, Endurance Road, etc.), they determine the best combination of properties—including stiffness, compliance, strength, and weight—for each product. With the experience as a foundation, the development of every FACT bike or piece of equipment moves through an integrated process where design, materials, and manufacturing are all chosen in careful consideration of one another. This integration of development ensures that each product is 100% built for its intended application—to give the rider exactly what they’re looking for, every ride.
OUR PROS HELP POWER OUR INNOVATION Sure, there’s an obvious draw to sponsoring two Pro Tour teams (not to mention our individual athletes and grassroots teams)—the race wins, the brand presence, the “cool factor” of being associated with riders who can pedal over 250km a day. But the real luxury in sponsoring teams like Saxo Bank is that they know exactly what they need and want, and they aren’t afraid to ask for it. By giving us feedback and suggestions on our bikes and equipment, they help us develop better products and drive innovation. For our newest time trial machine, the Shiv (winner of the 2009 TT World Championships), we worked with Saxo Bank every step of the way to help develop the geometry, frame shape, and layup and to validate our prototype frames. Fabian Cancellara, the Schleck brothers, and Team Director Bjarne Riis were particularly integral to the process, giving us priceless feedback we couldn’t get anywhere else. From the start, Riis set definitive performance targets for the Shiv. He had ridden our Transition—previously our only triathlon/time trial bike—and came back with a laundry list of suggestions for the new frame.
SAXO HAD SPECIFIC STIFFNESS REQUIREMENTS AND WANTED SOMETHING SLIPPERY FAST. OUT WITH CONVENTIONAL AERO TUBING, IN WITH ALL-NEW DESIGN CONCEPTS. THIS REQUIRED RADICAL ENGINEERING OF ALL TUBE SHAPES. FRAME SHAPE
DEVELOPMENT PROCESS DESIGN & ENGINEERING
PAGES 7-10
SAXO ASKED FOR AGGRESSIVE AND FAST. WE LARGELY DESIGNED AROUND FABIAN’S GEOMETRY AND HANDLING CHARACTERISTICS FOR THE XL SHIV, THEN ADAPTED THE TECHNOLOGY FOR OTHER FRAME SIZES. GEOMETRY
SAXO’S STIFFNESS AND AERODYNAMIC DEMANDS WERE ONLY ACHIEVED THROUGH SYSTEMS INTEGRATION OF COMPONENTS LIKE THE HEAD TUBE, STEM, BRAKES, BB, AND CRANKSET. NOTE THE SEAMLESS DESIGN OF STEM, STEERER, AND FRONT BRAKE. SYSTEM INTEGRATION
MATERIALS SELECTION
PAGES 11-14
FABRICATION PROCESS
PAGES 15-17
TESTING/REVISION IN LAB & FIELD
PAGES 18-23
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DESIGN & ENGINEERING
DESIGN & ENGINEERING
TUBE SHAPE BY DESIGN
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CARBON-CENTRIC DESIGN We approach the engineering of our tube shapes and joints through a concept we like to call carbon-centric design. Carbon can be molded into just about any shape with proper engineering, but by designing tube shapes with the properties of the material in mind, we can create a much more optimized structure.
Frame prepared for strain-guage testing
We design and optimize each tube size for each frame size. Here we show down tube sizes.
Beyond just aesthetics, the shape of a carbon frame or component has a huge impact on how it will perform. Smart tube shapes don’t just happen; they are the result of months of R&D, field testing, and years of experience riding previous models, including those of competitors. Here are the factors we consider when optimizing tube shapes:
STRAIN GAUGING — Allows us to determine the ratio of bending vs. stiffness in each tube and to compare the relative importance of those tubes in different stiffness scenarios. FEA STUDIES — Through this computer modeling software, we can isolate different tubes for pure bending or torsion
stiffness load cases or a combination of both. Full frame studies show the effect of triangulation in the front and rear triangles and the effect of a bowed top tube on compliance.
EXPERIENCE — Simple. We watch how tubes deform in dynamic and static fatigue tests and make modifications based on our findings.
TUBE LOCATION — Our tube shapes are designed to resist specific forces, depending on their location. We shape the top tube differently than the down tube, for example, because each tube sees more or less loading, plus a different ratio of bending and torsion stress, depending on the riding scenario (e.g. sprinting, descending, etc.). FRAME SIZE — The way we see it, different frame sizes warrant different tube sizes. If we didn’t design each tube in this manner, a larger frame would have inherently lower stiffness due to the length of its tubes (meaning they flex more than a short tube under the same load). And at the same time, larger riders are capable of applying more force on their bikes. This makes determining the appropriate level of stiffness for each size bike/rider extremely important. By designing the top tube, down tube, seat tube, and seatstays for each frame size, we can accurately and efficiently control stiffness variables from our smallest to largest frame sizes. Though size-specific tubes require much more work from the engineers who have to painstakingly design each tubeset, the result is a proportional range of bikes with consistent ride qualities across every platform (e.g. Tarmac, Roubaix, Amira, etc.).
On its own, carbon fiber only possesses tensile strength. But when a flat sheet of prepreg (resin-impregnated carbon) is cured, it gains some compression strength and some bending strength. So by properly layering these prepreg sheets during the bike’s layup process and utilizing the carbon in an efficient geometric shape, we can create tubes that are capable of resisting tensile, torsion, and compressive forces, all of which we encounter while riding. The real science lies in the ply angles of the carbon. Zero-degree carbon plies work to resist bending and +/- 45 degree angle plies resist torsion. When twisted, either the + or - 45 degree fibers are in tension (depending on the twisting direction), but when bending, one side of the tube is in tension and the other in compression. Long story short, by putting as many fibers as possible in tension (carbon is at its best when it’s in tension), we can create a stronger, stiffer bike. This is why it’s fundamental for us to know the ratio between bending and torsion in each tube. Beyond the properties of the material itself, here are the other considerations we make in carbon-centric design: Carbon fibers aren’t as strong when bent at extreme angles, so our engineers focus on eliminating sharp corners, creating smooth transitions, and utilizing large radii tubes. To maximize structural properties such as strength and stiffness, our engineers use frame and tube geometry to their greatest advantage—an example being the Tarmac SL3’s large down tube and bottom bracket junction, which helps the bike achieve a superior stiffness-to-weight ratio. We eliminate the need for extra carbon material (which other manufacturers might use to build in a margin for error to account for less-than-precise manufacturing) by making our tooling, layup, and molding processes as efficient as possible. Our hard work early on in the design process is what allows us to make frames and components of such consistent quality.
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MATERIALS SELECTION
DESIGN & ENGINEERING
FACT FORKS GO CARBON-CENTRIC
MATERIALS SELECTION THE PROCESS BY WHICH WE SELECT MATERIALS FOR OUR FACT BIKES AND EQUIPMENT
A carbon road fork undergoing ultimate strength testing
A cut-away of our tapered crown design. U.S. patents 7, 520,520 and 7,537,231
FIBER SELECTION
RESIN SELECTION
STIFFNESS (E) AND STRENGTH (Y)
TOUGHNESS
FIBER TYPES
TEMPERATURE RESISTANCE
WEAVE TYPE UNI WEAVE
Carbon-centric design doesn’t stop at frames; every component we create, including our FACT carbon forks, follows the same design philosophy.
3K OR 12K WEAVE
Traditional fork designs use a large flat crown surface as a seat for a standard crown race—a design borrowed directly from alloy and steel forks. However, since this shape demands 90-degree changes in geometry, it diminishes the effectiveness of the carbon fibers (considering, as we said before, that carbon is strongest in tension).
TWILL WEAVE
In 2007, we introduced our first tapered crown/raised bearing design and put it on our Roubaix bike. The tapered section of the crown accommodates the bearing and allows the carbon fibers to flow smoothly between blade, crown, and steerer. By virtue of its geometry, tapering also provides a stiffness/strength advantage that we can prove through FEA studies. Finding this design to be widely successful, we’ve since applied it to all of our FACT full carbon forks, and now, we even use raised bearings on the majority of our carbon mountain bikes.
PREPREG MANUFACTURING RESIN CONTENT RESIN ADDITIVES
Fork strength and stiffness are, without question, two of the most important attributes of the bike and something we really focus on during development and testing. Strength aside, stiffness is what makes your front wheel track well when cornering and descending, so it’s paramount to the quality of your ride. By increasing both lateral fork stiffness and steerer tube torsion stiffness, our tapered crown design creates a more confident handling bike.
COLD STORAGE UNTIL ASSEMBLAGE OF PRE-FORM
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MATERIALS SELECTION
MATERIALS SELECTION
STIFFNESS (E) AND STRENGTH (Y) Not all carbon fiber is created equal. Some fiber has higher tensile strength (represented by the letter Y in the FACT chart), meaning “stronger”, and other fiber has superior stiffness properties (represented by the letter E in the FACT chart). Both properties are considered in any carbon project, but to varying degrees; road bikes are usually more concerned with stiffness, while mountain bikes focus more on strength. To help us rank our composite bikes against ourselves and the competition, we’ve developed a chart that compares the material strength and stiffness, manufacturing methods, and finish layers applied to each fact frame. The column at the right titled “FACT Rating” is an internal numbering system we’ve created to represent the materials and manufacturing applied to each FACT bike. When comparing the E and Y-series carbon used for each bike, keep in mind that the higher the number, the greater the stiffness/strength.
FIBER TYPES
TARMAC S-WORKS TARMAC SL3 TARMAC PRO/EXPERT SL TARMAC COMP & ELITE
Modulus is an engineering term for fiber stiffness. Though high modulus carbon is good for stiffness, it tends to have lower elongation at failure. 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 our frames as light and stiff as possible without sacrificing strength or durability. The general idea is to align the higher strength material with loads and to save as much weight as possible everywhere else with stiffer high modulus material.
FACT RATING
MATERIAL
MANUFACTURING METHOD
FINAL LAYER
FACT 11R FACT 10R FACT 8R
E630 E390 E240
FACT IS FACT IS TRIPLE MONOCOQUE
UNI 12K 12K
FACT 10R FACT 9R FACT 7R FACT 6R
E390 E285 E285 E240
FACT IS FACT IS TRIPLE MONOCOQUE TRIPLE MONOCOQUE
UNI 12K 12K 12K
FACT 10R FACT 9R FACT 7R
E390 E285 E240
FACT IS FACT IS TRIPLE MONOCOQUE
UNI 12K 12K
FACT 10R FACT 8R
E390 E285
FACT IS FACT IS
UNI 12K
FACT 10M FACT 8M FACT 10M FACT 8M FACT 11M FACT 9M FACT 10M FACT 10M FACT 10M FACT 10M FACT 8M FACT 9M FACT 10M FACT 9M
Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579 Y579
TRIPLE MONOCOQUE TRIPLE MONOCOQUE TRIPLE MONOCOQUE TRIPLE MONOCOQUE FACT IS FACT IS FACT IS FACT IS FACT IS AZ1 FACT IS AZ1 FACT ISX FACT ISX
UNI 12K UNI 12K UNI 12K UNI UNI UNI UNI 12K 12K UNI 12K
FACT 10M FACT 10M
Y579 Y579
AZ1 AZ1
UNI UNI
FACT 9R FACT 7R
E390 E285
TRIPLE MONOCOQUE TRIPLE MONOCOQUE
UNI 12K
ROUBAIX S-WORKS ROUBAIX ROUBAIX PRO & EXPERT ROUBAIX COMP & ELITE ROUBAIX (BASE)
RUBY RUBY S-WORKS RUBY PRO/EXPERT RUBY COMP/ELITE
AMIRA AMIRA S-WORKS AMIRA EXPERT/COMP
MOUNTAIN S-WORKS HARDTAIL SJ MARATHON & EXPERT HT S-WORKS HARDTAIL, 29ER SJ MARATHON & EXPERT HT , 29ER S-WORKS EPIC EPIC MARATHON & EXPERT S-WORKS ERA ERA EXPERT S-WORKS SJ FSR S-WORKS SAFIRE STUMPJUMPER FSR PRO & EXPERT SAFIRE EXPERT S-WORKS ENDURO ENDURO PRO
TRICROSS S-WORKS TRICROSS TRICROSS PRO
TRANSITION S-WORKS TRANSITION PRO, EXPERT & COMP TRANSITION
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ULTRA HIGH MODULUS PITCH FIBER
Pitch fiber is nearly double the stiffness of high modulus fiber, but lacks strength compared to lower modulus materials. It’s also very expensive and difficult to manipulate. Because of this, we use it very sparingly and strategically—only on S-Works bikes like the Tarmac SL3 and Epic and only in places that will benefit the most from a major boost in stiffness.
HIGH MODULUS
Rated at 40 Ton or 57Mpsi (millions of pounds per square inch). That’s about 62% stiffer than the standard aerospace-grade material most carbon bicycles use. At triple the cost of standard modulus fiber, this fiber is used extensively in S-Works and Pro-level frames.
INTERMEDIATE MODULUS
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. “Intermediate” might not sound like the pinnacle of technology, but don’t be fooled—this material has an optimum blend of stiffness and strength to make your bike as damage-tolerant and stiff as you expect it to be.
STANDARD MODULUS
Aerospace-grade carbon fiber used in conjunction with other materials for improved impact strength in specific areas. Note: Some companies call any aerospace-grade material “high modulus” when, in fact, it’s industry standard modulus material.
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MATERIALS SELECTION
FABRICATION PROCESS
WEAVE TYPES
A STEP-BY-STEP GUIDE TO FACT CARBON MANUFACTURING
UNI-DIRECTIONAL PROS
CONS
WHERE WE USE IT
MOST EFFICIENT USE OF MATERIAL BECAUSE FIBERS REMAIN THE STRAIGHTEST
DIFFICULT TO GET PERFECT COSMETICS
ALMOST EVERYWHERE— ALL FRAMES USE UNI-DIRECTIONAL FIBER FOR THEIR MAIN STRUCTURE
3K OR 12K WEAVE
STEP 1: TOOLING
The first step is for us to create a custom-made steel mold that defines the exact outside shape and surfaces (the part of the frame you can see) of the frame. Depending on the part it’s being created for, a steel mold may take 8-12 weeks to make. Why so long? Because it’s a big chunk of steel that’s precision CNC’d, weighs a few hundred pounds, and must be accurate to within a few thousandths of an inch in every aspect. A finished frame section or part comes out weighing just a tiny fraction of the tool. Assuming the mold is made correctly, the finished part will have the same level of accuracy as the mold.
STEP 2: LAYUP AND PRE-FORM
ABRASION RESISTANCE, IMPACT RESISTANCE, COSMETICS
NOT AS STIFF AS EQUIVALENT UNI-DIRECTIONAL PLIES
IN DAMAGE-PRONE AREAS
TWILL WEAVE
CONFORMS TO RADICAL SHAPES
NOT AS EFFICIENT AS EQUIVALENT UNI-DIRECTIONAL PLIES
ON VERY DIFFICULT PARTS SUCH AS OUR SHIV SEAT TUBE
In this important step to the manufacturing process, flexible sheets and pieces of prepreg are wrapped over a pre-form mandrel and assembled into the shape of a frame, fork, or part according to a heavily revised Layup Schedule Development (see page 16 for details). Arguably, a pre-form can be anything; a round tube, the nylon bladder used to mold the frame, or even just a piece of wood. But in the case of our highest end bikes, we want the pre-form shape to mimic the shape of the mold cavity as closely as possible. So we take the time to engineer a mold for all of our pre-forms and invest in the tooling required to make some of the most advanced mandrels used in the composites industry. These super accurate pre-forms allow us to mold very complex shapes (like the Shiv’s seat tube or the bottom bracket of the Tarmac SL3) and optimize fiber alignment, which is key to achieving the ultimate in stiffness. Next, we place an air bladder made of pressure-resistant nylon inside the flexible composite layup structure. Its function is to internally pressurize the composite material in the layup against the tooling surface to eliminate internal voids in the composite structure. By using silicone lining in conjunction with the bladder during molding, we can ensure adequate compaction in areas with complex geometry. Still pliable, the entire prepreg assembly, including the bladder, is placed inside its big steel mold. The multi-piece mold is closed and locked down, and the bladders are connected to pressurized air fittings.
Head tube pre-form mandrel
BB pre-form mandrel and resulting carbon fiber layup ready for molding
STEP 3: MOLDING
PREPREG MANUFACTURING Prepreg is defined as flexible sheets of carbon that have been “impregnated” with resin. During the layup process, these sheets are strategically layered into pre-form shapes before getting baked in a mold. Unique to Specialized, we make our own prepreg from both uni-directional and woven materials, even weaving our own fabric. This allows us to control exactly what goes into our bikes, from the fiber to the resin content to the process by which the prepreg is manufactured. We use the hot melt process for making prepreg—the most sophisticated method available.
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After determining the appropriate materials selection for each family of bike (and even each bike size within that family), our engineers use 100+ pieces of carbon fiber to create specific carbon layups that yield the perfect combination of stiffness, compliance, strength, and weight. Whether it’s the super stiff Tarmac or more balanced Roubaix, we can optimize performance for any given experience.
The closed mold moves on a conveyor into an electric hot press where its temperature is raised to 155° c (that’s 311°f or 428.1 K.) The high temp allows the resin in the prepreg to liquefy and spread uniformly in the composite layup. To help aid in the process, the bladders inside the prepreg assembly are pressurized to 150 psi. This mixing of resin in the carbon fabric is called “wet out”, a critical component to the integrity of the molded structure. Too little pressure in the bladder and the composite won’t wet out effectively, leaving high-resin areas that add useless weight and low-resin areas that weaken the structure. Too much pressure and the resin 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 claim “ultra-low” resin content. This is not good! The mold stays at this temperature for about 30 minutes depending on its size, then it must cool down. Due to the size and mass of the steel tooling, this takes another 20-30 minutes. Once the frame inside the mold has cooled enough, the resin is cured and cannot be changed. If there is even a minor defect or issue with alignment, the entire frame must be scrapped. These types of unchangeable composite structures are called thermoset; structures made with a different matrix that can be re-heated and changed are called thermoplastic.
Cured composite section (top tube, down tube, head tube) after molding
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FABRICATION PROCESS
DETAILS ON OUR LAYUP SCHEDULE DEVELOPMENT (LSD) The anisotropic (directional-specific) nature of advanced composite materials allows Specialized engineers to use weaves and ply designs to create carbon structures 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 layup patterns of a particular frame or component to optimize performance characteristics for its intended use. The resulting pattern of layers of carbon fibers is called a layup. The overall protocol we use at Specialized for developing layups is called Layup Schedule Development or LSD.
FABRICATION PROCESS
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PROPRIETARY MANUFACTURING METHODS 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 manufacturing methods for accomplishing this, but after years of refining thousands of frames, we’ve settled on two advanced and precise methods: FACT IS (Integrated Structure) and Triple Monocoque.
FACT IS
FACT IS Method
FACT IS our most advanced carbon construction method. By separating the frame into four large monocoque structures—head tube/top tube/down tube, seat tube, seatstays, and one-piece bottom bracket chainstay—this method allows the carbon fibers to run continuously from tube to tube, offering advantages in weight, stiffness, and strength. FACT IS frames include: ROAD - S-Works, Pro, and Expert models of Tarmac, Roubaix, and Ruby; all Amira and Shiv models.
The major layup 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 (i.e. along the “axis” of the tube) and are referred to as “zero” fibers. These fibers give the frame a lot of strength for in-line impacts and loads and make the frame resistant to bending. Some fibers run at angles of plus or minus 45°, 30° or 22.5°. These fibers give the frame its torsional (twisting) stiffness.
MOUNTAIN – Epic S-Works, Marathon, Expert, and Comp models; Era S-Works and Expert models; Stumpjumper FSR S-Works, Pro, and Expert models; Enduro S-Works and Pro models
Each frame has a detailed laminate schedule. The tubes have five or six main plies, but there are over 100 pieces of carbon fiber in a frame’s layup—precisely why LSD is such an involved process. Placement of smaller pieces of carbon fiber at tube junctions minimizes overall weight and helps the joints handle loads. From the largest to the smallest, every sheet or piece of carbon is cut and placed by hand, making staff training and quality control a top priority. Once completely assembled, the carbon fiber layup is called a pre-form. At this state, it’s pliable and ready for molding and curing.
TRIPLE MONOCOQUE
Triple Monocoque is a balanced approach to frame assembly that minimizes seams and redundant materials. 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 aero-space adhesives and a final carbon wrap. Triple Monocoque frames include: ROAD – Tarmac Comp and Elite models; Roubaix Comp, Elite, and base-level models; Transition S-Works, Pro, Expert, and Comp models; Ruby Comp and Elite models Triple Monocoque Method
MOUNTAIN – Stumpjumper HT S-Works, Marathon, Expert, and Comp models; Stumpjumper HT 29er S-Works and Expert models Note: For 2010, the S-Works Tricross and Safire S-Works and Expert models still utilize our Az1 manufacturing method, but FACT IS is becoming the more prominent construction for our high-end bikes.
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TESTING & REVISION
TESTING & REVISION
TRIED AND TESTED TEST METHODS & DATA
After manufacturing, initial frame prototypes are lab-tested to achieve required strength and stiffness at all junctions and load points. Then we start test riding all frame sizes with elite and pro 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.
With one of the world’s foremost testing facilities housed in our Morgan Hill, CA, headquarters, our engineers and technicians can perform countless hours of testing in all phases of fatigue, ultimate strength, impact strength, stiffness, and vibration. For competitive analysis, we publish data on the two most universally accepted modes of comparison: weight and stiffness.
Based on our findings, multiple iterations of the frame’s layup are generated to balance stiffness, vibration damping, perceived road feel, and of course, overall strength. Even with all of our high-tech testing software and feedback from the world’s best riders, it takes a minimum of five iterations to optimize all parameters and, sometimes, far more. With the final layup determined, we conduct a number of destructive lab tests (with multiple samples for each size) to verify that the layup is stable and predictable.
There are a number of commonly accepted stiffness measurements that everyone in the industry uses, but we’ve also adapted our own proprietary tests to further analyze and fine tune specific parts of the frame. Here we will focus on torsional and BB stiffness-to-weight, module BB stiffness, rear triangle stiffness, and vertical compliance.
MODULE SYSTEM WEIGHT The test for weight is simple. We take a finished 56cm or equivalent frame and put it on the scales. Module weights include frame, fork, hardware, seatpost, crankset and BB (53/39), and Dura Ace 7900, unless the frame is sold with a proprietary crankset. GRAMS
0
500
1000
1500
2000
2010 S-WORKS TARMAC SL3
2047
2009 SCOTT ADDICT R2 ISP
2049
2009 CERVELO R3 SL
2101
LAYUP DEVELOPMENT THROUGH TESTING
2009 SCOTT ADDICT SL
2119
Each frame goes through this layup process to achieve engineering targets.
2009 CERVELO SOLOIST SLC-SL
2244
Note: Since the Tarmac SL3 is our flagship road race bike for 2010, we use it most widely as our basis for comparison against competitors.
2009 CANYON ULTIMATE CF SLX
LAYUP DESIGN
LAB STIFFNESS
LAB STRENGTH
REPEAT UNTIL TARGETS ARE MET
This is an overall torsional measurement from head tube to rear dropouts—it indicates how well a frame will handle in turns and how stable it will be at high speed. The higher the number, the stiffer the frame. The frame is fixed at the rear dropouts and a single point support at the middle of head tube that allows the head tube to move. By weighting the bar extending from the head tube (acting as a fork) at the point of tire contact, this test measures the torsional deflection (twisting) along the entire length of the frame, not just a single section. To deduct stiffness-to-weight, the numerical results for torsional stiffness are divided by frame weight.
(N*m/deg)/kg)
2271
0.0
2271
20.0
40.0
2280
2009 CERVELO R3 SL
2009 CANNONDALE SUPER SIX
2285
2009 SCOTT ADDICT SL
2009 GIANT TCR ADVANCED SL2
2302
2009 SCOTT ADDICT R2 ISP
2009 RIDLEY NOAH
2010 PENARELLO DOGMA 60.1
2500
80.0
100.0
2559 2674
111.2
99.8 93.7 90.5
2009 CANYON ULTIMATE CF SLX
84
HEAVIEST
77.2 76.6
2010 TREK MADONE 6 SERIES
74.5
2010 PENARELLO DOGMA 60.1
74.5
2009 CERVELO SOLOIST SLC-SL
71.8 70.5
LOWEST RATIO
2009 CANNONDALE SUPER SIX
140.0
104.6
2009 GIANT TCR ADVANCED SL ISP
2009 RIDLEY NOAH
120.0
124.3
2009 GIANT TCR ADVANCED SL2
2009 2009 PENARELLO PINARELLO PRINCE
FINAL LAYUP
60.0
2010 S-WORKS TARMAC SL3
2009 GIANT TCR ADVANCED SL ISP
2009 PENARELLO PRINCE
LONG-TERM RIDE TEST
STIFFNESS-TO-WEIGHT TORSION TESTING
3000
HIGHEST RATIO
2010 TREK MADONE 6 SERIES
2500
LIGHTEST
RIDE AND REVISE
19
20
TESTING & REVISION
TESTING & REVISION
21
STIFFNESS-TO-WEIGHT BB TESTING
VERTICAL COMPLIANCE TESTING
MODULE BB STIFFNESS TESTING
REAR TRIANGLE STIFFNESS TESTING
Just like torsional stiffness-to-weight, a higher number indicates greater stiffness. Generally, the stiffer the structure is to the rider’s pedaling forces, the faster the frame will respond to rider acceleration. With the SL3, we shot for a high stiffness number, then focused on maximizing torsional and rear triangle stiffness, while reducing weight.
This test measures how a frame responds to loads applied in a vertical plane, which correlates to ride comfort. As a frame gets more compliant, it becomes less stiff. A higher number represents more compliance. This is an isolated vertical compliance test, independent of torsional or BB stiffness.
A BATTLE OF THE BOTTOM BRACKETS: WIDE BB VS. SPECIALIZED OSBB
Sometimes stiffness and weight measurements are too general. So we conduct several proprietary tests on select parts of the frame to help us analyze variables that might otherwise get overshadowed. We won’t reveal too many details into this process, but one such test is rear triangle stiffness.
For this test, 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 at the pedal through a simulated crank arm and chain at the power-stroke position, then the deflection at the BB is measured and the results are divided by frame weight.
Each frame is positioned vertically—allowing it to roll at the front and rotate at the rear dropouts—and a vertical force is applied at the saddle. The distance between the BB center and the top of the seatpost is kept constant on all frames. The deflection measures the ability of the frame and seatpost combination to absorb shock in a vertical plane.
(N/m)/kg
(mm/kN)
20.0
40.0
60.0
80.0
100.0
120.0
140.0
160.0
0
145.9
2009 CANYON ULTIMATE CF SLX
145.7
2009 CERVELO SOLOIST SLC-SL
144.4
2009 GIANT TCR ADVANCED SL2
142.9
4
5
5.14
6
4.55
2008 CERVELO RS
2.56
To illustrate this concept, we created a new test called “Module BB Stiffness” (see pg. 18 for picture of test). It’s set up just like a standard BB stiffness test, but the frame is paired with the real crankset to better measure the BB stiffness of the overall system. As you can see, we clearly out-perform the other guys. Note: The competition’s modules are tested with a Dura Ace 7900 crankset.
0.0
20.0
40.0
2009 RIDLEY NOAH
121.2 117.9
2010 PENARELLO DOGMA 60.1
117.4 114.8
80.0
100.0
120.0
125.2
2010 S-WORKS TARMAC SL3
30.0
40.0
57.9
2009 GIANT TCR ADVANCED SL ISP
50.7
2009 CANNONDALE SUPER SIX
50.7
48.3 46.6
2010 PINARELLO DOGMA 60.1
45.1 42.9
2009 CANYON ULTIMATE CF SLX
39.6
2009 PINARELLO PRINCE
38.8
2009 RIDLEY NOAH
2010 TREK MADONE 6 SERIES
70.0
48.9
140.0
2009 CERVELO SOLOIST SLC-SL
60.0
55.5
2009 GIANT TCR ADVANCED SL2
110.8 100.8
50.0
2010 S-WORKS TARMAC SL3
2009 SCOTT ADDICT R2 ISP 2009 GIANT TCR ADVANCED SL ISP
LOWEST RATIO
2009 PENARELLO PRINCE
20.0
36.7 33.7
LEAST STIFF
2010 TREK MADONE 6 SERIES
60.0
LEAST STIFF
121.3
10.0
2009 CERVELO R3 SL
2010 TREK MADONE 6 SERIES 2009 CANNONDALE SUPER SIX
0.0
2009 SCOTT ADDICT SL
(N/mm)
STIFFEST
2009 SCOTT ADDICT R2 ISP
3
2009 S-WORKS ROUBAIX SL2
2008 CANNONDALE SYNAPSE
151
2009 SCOTT ADDICT SL
2
LEAST COMPLIANT
152
2009 GIANT TCR ADVANCED SL ISP
1
COMPLIANT
162.8
2010 S-WORKS TARMAC SL3
200.0
HIGHEST RATIO
181.4
2009 CERVELO R3 SL
180.0
It’s important to note that both 90mm and 68mm bottom brackets allow for a larger diameter down tube and seat tube, which will inevitably increase stiffness. But since our OSBB system is designed in tandem with our FACT carbon crankset, we can achieve even greater module BB stiffness than the 90mm designs, while still remaining BB30-compatible.
(N/mm)
STIFFEST
0.0
Some of our competitors have made slanted claims about the superiority of wide bottom brackets, and we wanted to set the record straight: Using an ultra-wide 90mm BB, in contrast to a proprietary system like our 68mm OSBB or even the standard BB30, doesn’t in itself make for a stiffer frame.
22
TESTING & REVISION
TESTING & REVISION
CRANK SYSTEM STIFFNESS DATA
CRANK SYSTEM WEIGHT DATA GRAMS
(N/mm)
0
50
100
150
200
0
250
171.8
SHIMANO DURA ACE
TIME ASX TITAN CARBON
151.8
TIME ASX TITAN CARBON
BONTRAGER RACE X LITE
151
BONTRAGER RACE X LITE
Our 2nd generation S-Works SL FACT Carbon Crankset is one of the best examples of the merits of systems integration. This proprietary crank is designed together with our oversized bottom bracket shell (also BB30 compatible) to deliver superior stiffness, strength, and balanced performance at only 597 grams—that’s lighter than even the biggest names in components. KEY FEATURES — Lightest and stiffest crankset on market; see charts — FACT carbon removable spider — Self-adjusting 42mm ceramic cartridge bearings — Smooth-shifting S-Works SL aluminum chainrings — BB30 compatible INTEGRATED CARBON-CENTRIC DESIGN Creates best weight and stiffness with better fatigue life. The S-Works SL FACT Carbon Crankset uses a patented integrated construction that’s functionally different from traditional configurations. Typical carbon cranks cut fibers at the BB axle/arm interface, which creates a potential weak spot in a very high-stress area. But the SL’s integrated crank design allows the carbon fiber to transition seamlessly into the bottom bracket with only one connection point at the center of the BB shell—eliminating the typically independent BB axle. Since this design optimizes the layup of carbon fiber within the bottom bracket, we can engineer the SL crank with completely hollow crank arms for greater stiffness and lighter weight and even add material at the center connection for more strength (without a weight penalty). Finally, replacing the typical steel bearings with new ceramic bearings adds durability and offers less rolling resistance. REMOVABLE CARBON SPIDER Balances stiffness and gives the rider more options. Most crank spiders are integrated into the right crank arm and create big discrepancies in crank arm stiffness from left to right—a fact that’s often hidden by overall weights and measurements that don’t take side-to-side balance into account. The SL’s removable carbon spider balances stiffness from left to right, adding to the efficiency of your pedal stroke. At the same time, it gives riders interchangeability between different spider and chain ring sizes and also enables the use of SRM and Quarq power meters. The S-Works SL crank is found exclusively on the S-Works Tarmac SL3, but is also available aftermarket.
CAMPY RECORD UT FSA SL-K STANDARD
800
900
603
610 760 632 770 695 799 HEAVIEST
The numbers we pulled from the transducer frame allowed us to optimize the shapes of our bikes to resist the specific loads they would encounter in the field. Take a good look at a bike like the Tarmac SL3—think about how each tube is designed with variable diameter, shifting from circular shapes to flatter, more rectangular ones, yet all blending together—these subtle changes are no accident.
THE STIFFEST, LIGHTEST SYSTEM AVAILABLE. NO JOKE. LEAST STIFF
The transducer frame was ridden in every possible manner—sprinting, climbing, descending, pedaling while turning, etc. From the tests, we gathered mountains of data that illustrated the relationship of bending vs. torsion in each tube and how each tube relates to the other. We mapped the load paths through the entire bike frame in every riding situation.
S-WORKS SL FACT CARBON CRANKSET
148.8
Note: See pg. 23 for photo of crank stiffness test.
597
750
MOVING BEYOND STATIC TESTS AND COMPUTER SIMULATIONS
Stiffness tests are a great benchmark for frame development, and finite element analysis allows rapid prototyping, but the act of riding is so dynamic that it can’t be fully duplicated with a static test or computer simulation. Naturally, we saw these limits as opportunity. After a long, arduous process, we found a way to turn the bike frame into a ride-able transducer, capable of gathering bending and torsion data along each tube.
700
SRAM RED
165.6
136.3
600
SHIMANO DURA ACE
SRAM RED
FSA SL-K STANDARD
500
742
THE BIKE AS A RIDE-ABLE TRANSDUCER
CAMPY RECORD UT
400
SHIMANO DURA ACE FC-7900
ZIPP VUMA QUAD
168.1
ZIPP VUMA QUAD
300
LIGHTEST
178.8
SHIMANO DURA ACE FC-7900
200
CANNONDALE BB30 SL
189.3
CANNONDALE BB30 SL
100
SPECIALIZED S-WORKS SL STD.
STIFFEST
195.6
SPECIALIZED S-WORKS SL STD.
We’ve made rapid advances in the last several years in terms of the performance and ride quality of our carbon frames. It’s not just our commitment to testing (read Mark Schroeder’s introduction on pg. 2 if you have any doubts) that pushes us forward, but our constant drive to get inside the bike (metaphorically speaking, of course) and determine exactly what’s happening in each tube under real riding and racing conditions.
23
SPECIALIZED BICYCLE COMPONENTS, INC.