About Titanium

Titanium alloys are high performance alloys that offer a unique combination of high strength, low density, excellent fatigue and corrosion resistance. The performance of Titanium alloys makes them the ideal choice for bicycle frames and other tubular structures.

Titanium as a raw element is often thought of as being rare; this, in fact, is not the case. Titanium is an abundant element with large deposits occurring in Australian beach sand. Unfortunately, Titanium's extreme reactivity with oxygen makes it difficult to produce in metallic form. The manufacturing process of turning the raw Titanium into seamless tubes for use in high performance bicycle frames is a long and expensive one.

Ti 3-2.5 utilizes an alloy of Titanium with 3% aluminum and 2.5% vanadium; commonly know as Ti-3-2.5. Ti-3-2.5 was developed for the aerospace industry for use in high pressure hydraulic lines and is found on virtually all new commercial and military aero planes being built in the Western World. Ti-3-2.5 balances the higher strength of some Titanium alloys and ductility of commercially pure Titanium to create an all round high performance material.

The high strength and low density of Ti-3-2.5 allows for the fabrication of tubular structures that are not only light weight but also extremely strong and durable. Titanium does not break down, rust or corrode in any type of atmospheric environment and its high fracture toughness and fatigue resistance results in structures that can take a pounding and will not fail prematurely.

Another interesting property of Titanium is its low elastic modulus. The elastic modulus is a measure of how stiff a material is and is directly related to a material's ability to transmit shock waves. Titanium's low modulus translates into a natural dampening effect on vibrations, allowing Titanium frames to have a smooth ride even without additional suspension elements. The combination of Titanium's high strength and low modulus makes the material very "springy"; in fact aircraft springs were one of the first user’s for Titanium alloys. Unlike conventional frames, the material allows for good energy transfer and does not sap energy from the rider like a suspension system or weaker frame materials would. All this goes into making a Titanium frame a great ride combined with the advantages of low weight and high durability.

Alloys

All metals on bikes are an alloy of some kind. An alloy is made by mixing together various metallic elements.

• Aluminum is commonly alloyed with any one or more of the following: copper, manganese, silicon, or magnesium.
• Steel is a mix of iron (which we all know rusts) carbon and other possible metals such as chromium, nickel, and molybdenum (remember chrome-molly frames?).
• Titanium frame is an alloy consisting of Titanium, with 3% aluminum and 2.5% vanadium commonly known as Ti-3-2.5.

Once the desired ratio of the above elements are selected, the metal is formed by melting, mixing and then cooling the mixture. All Titanium tubing is then cold worked into shape. Once the process is complete, the material may be heat-treated to further enhance its mechanical properties.

A comparison of the most common Alloys on Bikes

• The modulus of elasticity (its “springiness”). The higher the modulus of eleasticity, the stiffer the frame
• The yield strength of the material (onset of permanent bending). The higher the yield strength, the stronger the frame
• The density, which determines the weight of the tube. The higher the density, the heavier the frame, but often the stronger the frame. This is the eternal battle weight vs strength.

Material	Modulas of Elasicity (Gpa)	Yield Strength (Mpa)	Density (kg/m3)
Mild Steel	206	200 - 300	7750
Chromolly Steel	206	413	7750
Aluminium Alloy	69	276(6061-T6) - 503(7075-T6)	2768
Titanium Alloy (3al-2.5v)	91	760	4429