Materials Selection
FACT BIKES AND EQUIPMENT
Stiffness & Strength
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.
| Bike | FACT Rating | Material | Manufacturing Method | Final Layer |
| Tarmac | ||||
| S-Works Tarmac SL3 | FACT 11R | E630 | FACT IS | UNI |
| Tarmac Pro / Expert SL | FACT 10R | E390 | FACT IS | 12K |
| Tarmac Comp & Elite | FACT 8R | E240 | Triple Monocoque | 12K |
| Roubaix | ||||
| S-Works Roubaix | FACT 10R | E390 | FACT IS | UNI |
| Roubaix Pro & Expert | FACT 9R | E285 | FACT IS | 12K |
| Roubaix Comp & Elite | FACT 7R | E285 | Triple Monocoque | 12K |
| Roubaix (BASE) | FACT 6R | E240 | Triple Monocoque | 12K |
| Ruby | ||||
| Ruby S-Works | FACT 10R | E390 | FACT IS | UNI |
| Ruby Pro/Expert | FACT 9R | E285 | FACT IS | 12K |
| Ruby Comp/Elite | FACT 7R | E240 | Triple Monocoque | 12K |
| Amira | ||||
| Amira S-Works | FACT 10R | E390 | FACT IS | UNI |
| Amira Expert/Comp | FACT 8R | E285 | FACT IS | 12K |
| Mountain | ||||
| S-Works Hardtail | FACT 10M | Y579 | Triple Monocoque | UNI |
| SJ Marathon & Expert HT | FACT 8M | Y579 | Triple Monocoque | 12K |
| S-Works Hardtail, 29ER | FACT 10M | Y579 | Triple Monocoque | UNI |
| SJ Marathon & Expert HT, 29ER | FACT 8M | Y579 | Triple Monocoque | 12K |
| S-Works Epic | FACT 11M | Y579 | FACT IS | UNI |
| Epic Marathon & Expert | FACT 9M | Y579 | FACT IS | 12K |
| S-Works Era | FACT 10M | Y579 | FACT IS | UNI |
| Era Expert | FACT 10M | Y579 | FACT IS | UNI |
| S-Works SJ FSR | FACT 10M | Y579 | FACT IS | UNI |
| S-Works Safire | FACT 10M | Y579 | AZ1 | UNI |
| Stumpjumper FSR Pro & Expert | FACT 8M | Y579 | FACT IS | 12K |
| Safire Expert | FACT 9M | Y579 | AZ1 | 12K |
| S-Works Enduro | FACT 10M | Y579 | FACT ISX | UNI |
| Enduro Pro | FACT 9M | Y579 | FACT ISX | 12K |
| Tricross | ||||
| S-Works Tricross | FACT 10M | Y579 | AZ1 | UNI |
| Tricross Pro | FACT 10M | Y579 | AZ1 | UNI |
| Transition | ||||
| S-Works Transition | FACT 9R | E390 | Triple Monocoque | UNI |
| Pro, Expert & Comp Transition | FACT 7R | E285 | Triple Monocoque | 12K |
Fiber Types
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.
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.
Weave Types
| Uni-directional | |||
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Pros:Most efficient use of materials because fibers remain the straightest |
Cons:Difficult to get perfect cosmetics |
Where We Use it:Almost eveywhere – All frames use uni-directional fiber as their main structure |
| 3K or 12K Weave | |||
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Pros:Abrasion resistance, impact resistance, cosmetics |
Cons:Not as stiff as equivalent uni-directional plies |
Where We Use it:In damage-prone areas |
| Twill Weave | |||
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Pros:Conforms to radical shapes |
Cons:Not as efficient as equivalent uni-directional plies |
Where We Use it:On very difficult parts such as Shiv seat tube |
![]() We use the hot melt process for making prepeg — the most sophisticated method available |
Prepreg ManufacturingPrepreg 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. 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. |



