Everti: (Latin) - conquer, overcome by force                                                                    Everti is a registered trademark.

The density of titanium is nearly twice that of aluminum (though aluminum is the weaker of the two metals), but only 56% the density of steel. The stiffness of titanium is also about half that of steel. It therefore follows that the stiffness-to-weight ratio of the two metals is nearly the same. In English this means that titanium is nearly as strong as, but is lighter than steel.

 

Elongation numbers of a metal tell us how much a material will bend before it breaks. Titanium’s 20 – 30 % elongation beats out steel’s 10 – 15% and aluminum’s 6 – 12%. The lower the elongation number, the more brittle and breakable a material is. The higher the elongation number, the stronger the material is. So, the same amount of titanium stretched out into a tube will wear less than the same amount of steel or aluminum stretched out to the same size tube. Carbon fiber does not stretch; it must be molded into form.

 

Fatigue strength is another measurement taken to compare metals. Fatigue is the result of accumulated wear from repetitive cycles of force. Aluminum is notorious for having such a low fatigue strength that there is no threshold, no level of strain below which the metal will not fail. This means that the strain on a bike frame from each pedal stroke contributes to the frame’s fatigue failure.

 

The effect can be delayed by over sizing the tubes to add stiffness, but the tubes end up being very thin walled and give a bone-jarring ride. In comparison, titanium has a threshold below which it will never fail, no matter how many times the cycles of force are applied. Yes, this means that titanium will never fatigue and never fail as long as the load it bears is below a certain level (which the stress we put on it riding is).

You are probably wondering by now what the catch is. Can titanium be the wonder-metal it seems? A look at the price tag of a titanium frame indicates that cost is the prohibitive factor. The high cost of titanium is not due to scarcity of the material, but rather the processing involved in both extracting and manufacturing the metal. Titanium is actually highly abundant, being the fourth most available element in the Earth (after aluminum, magnesium and iron). The process of extracting the metal is costly and requires a great deal of energy. The processing requirements are cost-intensive also. Titanium has a reputation for being difficult to work with, though perhaps it is more accurate to say that it is more particular than other metals and requires meticulous procedures, making it time-consuming and labour-intensive.

 

The bicycle industry first saw use of titanium in the 1970s. It has taken some time before we have seen quality craftsmanship in its use.

 

So now you know the logic behind the claims of titanium as an ideal metal. The next step is to go out and ride one and see for yourself how titanium compares to other frames out there.

Why Ti?

It seems to be assumed knowledge in the bike industry that certain materials are superior to others for building frames. Titanium has certainly received a lot of attention and press in the last few years, and few of us would argue it as being unworthy. How many of us can list its advantages over its competitors? We have all heard the hype, but it can be difficult deciding what to believe once the marketing machines get started. For those who want concrete facts, here is some metallurgical information to support the choice of titanium.

 

Titanium is extremely resistant to corrosion. This property has lead to titanium’s use as storage containers for caustic materials in the chemical industry. For you as a cyclist, this means that all the salty roads, messy mud and stream crossing you ride over or through will not rust your bicycle, ever. Titanium frames are lifetime frames.