Editor’s note: This story first appeared in Bicycle Times issue #16, published in April 2012. Words by Jeff Archer. Photos by Wes Stearns.
Last issue began a series of articles discussing the merits of different frame material and featuring a vintage bike produced with that material. The first bike was a classic Schwinn Paramount made of the most classic material, steel. In this issue we’ll discuss titanium as a frame building material, using a Teledyne Titan as the example.
Running the numbers on titanium, things look pretty good. It is the fourth most common metallic element on earth, so availability isn’t an issue. (Titanium is commonly referred to by its symbol from the periodic table, “Ti.”) Ti comes in at around twice the density of aluminum but about half that of steel. The stiffness is roughly half that of steel, which results in roughly equal stiffness-to-weight ratios. Once again, the frame builder can choose wall thicknesses and tubing diameter to tune the ride characteristics.
So far, Ti looks to be a middle-of-the-road material when compared to aluminum and steel. Where Ti really shines is in the elongation and fatigue life categories. Elongation refers to the ability of a material to bend before breaking, which is a highly desirable quality for bike frames. Fatigue life is a measure of how many times a material can be stressed at a certain level. Fatigue life is nearly infinite for Ti as long as the loads are kept below a certain threshold. At a trade show years ago, a Ti frame maker had small squares of steel, aluminum and titanium and allowed you to bend the squares back and forth between your fingers. The aluminum squares would tear in half pretty quickly, steel would eventually form a crack, but the Ti squares would outlast your fingers.
Since we aren’t all riding titanium bikes, there must be a downside as well. While it is a common material, Ti requires a tremendous amount of energy to extract from ore, driving up the cost of the tubing. Ti is also difficult to machine or manipulate, making shaped tubing and small frame pieces expensive. It is also easily contaminated during the welding process, so extra steps must be taken to ensure cleanliness. With the extra material and fabrication costs, titanium will never be a low-cost frame material.
The Teledyne Titan was one of the earliest attempts at making marketable titanium frames and was sold from 1974 through 1976. The frames were advertised as being about two-thirds the weight of the steel frames of the era. They also earned a reputation as being flexible and crack-prone. Inserts were placed inside the frame to try and beef up the trouble areas. For some reason, the designers felt the need to be able to use standard-sized clamps, which resulted in two crimped areas on the down tube for the shift lever and cable guide clamps.
They also insisted on making a titanium fork, which suffered from a lack of stiffness and difficulty in fabricating dropouts. The only readily available tubing was commercially pure (CP) titanium, which isn’t as strong as the alloys used in current bikes. None of these problems were unsolvable, but the project lost steam after approximately 2,000 frames were produced.
Our example bike still sports the original Ti fork and is not cracked, unlike the three other frames we have owned. Components are mostly Campagnolo Record including the drilled crank set.
This bike can be seen at the Museum of Mountain Bike Art & Technology in historic downtown Statesville, North Carolina. If you can’t visit in person, check out the collection at www.mombat.org.Tweet Print