// MANUAL
Factors that lengthen product life:
• Smooth, uid riding style
• No “hits”, crashes, jumps, other “shots” to the bike
• Low mileage
• Lower body weight
• Less aggressive rider
• Non-corrosive environment (dry, salt-free air)
• Clean riding environment
WARNING: Do not ride a bicycle or component with any crack, bulge or dent, even a
small one. Riding a cracked frame, fork or component could lead to complete failure, with
risk of serious injury or death.
B. UNDERSTANDING COMPOSITES
All riders must understand a fundamental reality of composites. Composite materials cons-
tructed of carbon bers are strong and light, but when crashed or overloaded, carbon bers do
not bend, they break.
What are composites?
The term “composites” refers to the fact that a part or parts are made up of different com-
ponents or materials. You’ve heard the term “carbon ber bike.” This really means “composite
bike.” Carbon ber composites are typically a strong, light ber in a matrix of plastic, molded
to form a shape. Carbon composites are light relative to metals. Steel weighs 7.8 grams/cm3
(grams per cubic centimeter), titanium 4.5 grams/cm3, aluminum 2.75 grams/cm3. Contrast
these numbers with carbon ber composite at 1.45 grams/cm3. The composites with the best
strength-to-weight ratios are made of carbon ber in a matrix of epoxy plastic. The epoxy
matrix bonds the carbon bers together, transfers load to other bers, and provides a smooth
outer surface. The carbon bers are the “skeleton” that carries the load.
Why are composites used?
Unlike metals, which have uniform properties in all directions (engineers call this isotropic),
carbon bers can be placed in specic orientations to optimize the structure for particular
loads. The choice of where to place the carbon bers gives engineers a powerful tool to create
strong, light bicycles. Engineers may also orient bers to suit other goals such as comfort and
vibration damping. Carbon ber composites are very corrosion resistant, much more so than
most metals. Think about carbon ber or berglass boats. Carbon ber materials have a very
high strength-to-weight ratio.
What are the limits of composites?
Well designed “composite” or carbon ber bicycles and components have long fatigue lives,
usually better than their metal equivalents. While fatigue life is an advantage of carbon ber,
you must still regularly inspect your carbon ber frame, fork, or components.
Carbon ber composites are not ductile. Once a carbon structure is overloaded, it will not
bend; it will break. At and near the break, there will be rough, sharp edges and maybe
delamination of carbon ber or carbon ber fabric layers. There will be no bending, buckling,
or stretching.
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