Bicycle suspension systems can vary greatly. Comparison tests on shock-dampening ability, suspension travel, weight and stiffness, amongst others, reveal a spectrum of specifications and performance levels. Considering the range of differences, a few commonalities remain.
Virtually all off-road – and many road – bikes have a suspension system. The aluminum alloy fork tubing is a critical piece of the suspension system. The suspension system often uses aluminum 7050, a heat-treatable aluminum zinc alloy with high mechanical properties and fracture toughness. Aluminum 7050, also popular within the aerospace industry, offers excellent stress and corrosion cracking resistance and high strength at subzero temperatures.
Another suspension element is the use of an elastomer seal. This rubber grommet slides along the outer surface of the tube and is exposed to the elements. Mud and dirt can work their way in between the tube and the seal. This adds extra wear from friction, shortening the life of the seal.
LTAVD finishes – functional and aesthetic
Manufacturers have begun to address this with the use of low temperature arc vapor deposition (LTAVD). The vapor deposition process allows designers to apply finishes that are both functional and aesthetic, and also in this case, low temperature. LTAVD deposits metals and refractory compounds, such as titanium nitride (TiN), that can’t otherwise be easily applied.
Due to the heat-treated nature of aluminum 7050, TiN must be applied to surfaces with temperatures below 150 deg C. Temperatures higher than this result in a reduction in strength and fatigue of the tube.
However, with the use of vapor-deposition bonding is possible. The TiN coating strengthens, reducing friction and significantly increasing the tube’s fatigue life. Low-friction coatings have excellent wear and corrosion resistance. They are uniform; providing fine metallic finishes without the environmental impact or hydrogen embrittlement associated with plating.
The range of tempered and forged parts coatable without compromising hardness, surface integrity or grain orientation increases the value of LTAVD. In addition, surface properties can be tailored for appearance, wear resistance, corrosion resistance and more. LTAVD makes it possible for the full range of bicycle parts and components made from different materials to all have the same finish.
The use of vapor deposition, and specifically LTAVD, can significantly increase the strength and life of the bicycle and its components.
Contact the experts at Bend Plating to learn more.