In the broadest sense, the materials used in bicycle frame construction are selected for their relative combination of properties in three basic categories: Strength, Weight, and Stiffness.

Strength: Perhaps the most basic and universal of the three terms, this refers to the ratio of absolute weight a material can support before it fails or becomes permanently deformed. Strength is important, but in context: It is possible to have an extremely strong frame that handles terribly, or a frame that handles great but will buckle under the loads applied by an aggressive rider.

Weight: Somewhat of a no-brainer, this refers to how "heavy" or "light" a specific quantity of material is. Identical tubes--same diameter, same thickness, same dimensions--of different materials will have different weights. Weight is important, but in context: gains toward lightness are foolish if at the expense of strength.

Stiffness: The most frequently cited and equally oft-misunderstood aspect of frame material properties, this term is often used interchangeably with a material's flexibility. That is to say the degree to which a material can be distorted by a load without being permanently deformed. Stiffness is important, but in context: It is possible to have a very stiff material with little to no strength, and conversely to have a very flexible material that is extremely difficult to break.

Taking those three variables into account--both in absolute terms as well as in relation to the characteristics for a specific application--one can arrive at the ideal material for each individual bike. Depending on the intended use(s) of the bike, the ideal materials could be metals, synthetic composites, natural fibers or, as has increasingly been the case, a combination of several materials.

Even when simplified to the most basic terminology, the application of frame materials for bicycles can be terribly complex. Strength is a component of safety and durability moreso than of handling; stiffness has a more immediate impact on handling but also factors into durability. Both the relative strength of a material and its stiffness directly influence technical details such as tube thickness and diameter, and weight is an obvious practical consideration as well. Any way you slice it, the three are intrinsically complimentary when determining the ride characteristics of a frame.

Here at Ti Cycles, we hand-build frames from two primary materials: Titanium and Steel.