Frame Material: Which Is Right for Me?By Patrick Brady
Bicycle frames are made from four major materials: steel, aluminum, titanium and carbon fiber. Each has its place, its strengths, and its weaknesses. With so many choices out there, each rider must decide what their priorities are. Because no one bicycle can be among the lightest in weight, inexpensive, exotic in ride and gorgeously decorated, riders must choose what is most important to their cycling experience.
Steel has been used for the whole of the history of the bicycle. Steel was king for more than 100 years. As a result, bicycles made from steel have won every race out there; the great cyclist ever, Eddy Merckx, rode steel to each of his more than 300 wins. Bicycle tubing is generally referred to as chrome-moly due to the high content of chromium and molybdenum used in the alloy. As recently as the 1980s steel frames were competitive on weight, but they have since been surpassed for light weight by aluminum, titanium and carbon fiber. Today most people who purchase a steel bike do so for one of two reasons. They are generally either looking for an inexpensive bike that is highly durable or they are looking for a custom bike built by a custom maker whose work will take on the artful look of jewelry.
Aluminum began to be used for bicycle frames in the late 1970s, but it didn’t really become popular until the 1990s when many manufacturers began to use thin-walled, large diameter aluminum tubing. The frames were inexpensive to produce and often allowed a builder to shave nearly a pound from the frame’s weight while maintaining a high degree of stiffness. It was popular with the pros for most of the 1990s. Aluminum has had two drawbacks; durability has been an issue because aluminum fatigues quickly and the stiffness that makes them so efficient also gives a bone-jarring ride. It remains the best combination of low weight and affordability on the market which is why it is the choice of many budget-minded racers.
Titanium has always had an air of the exotic. Titanium doesn’t corrode, so frames made from it can be ridden unpainted. The cool grey luster of an unpainted frame is an unusual sight and guaranteed to draw admiring looks anywhere it goes. Titanium is twice as heavy as aluminum but four times as strong as steel, so it can make an unfailingly durable frame with a weight lower than possible with steel. It has a comfortable ride typically but doesn’t usually have the stiffness of a top racing frame. Unfortunately, titanium tubing is expensive and difficult to weld, which results in some of the most expensive frames on the market. Most of the builders specializing in titanium offer their frames in custom sizing so titanium is very often associated with having the ultimate fit.
Carbon fiber is the newcomer. While carbon fiber tubes have been used in frames for more than 25 years, the first monocoque (one-piece) frame was produced in 1987. Little did people know it was the wave of the future. Carbon fiber combines unsurpassed low weight with nearly unmatched stiffness that can be blended and matched in almost limitless ways. Not only can the material be manipulated in the formation if individual fibers, but the ways the fibers are laid up in the structure allows the design engineers to add strength and stiffness where it's needed while decreasing material in low-stress areas to reduce weight and increase vibration damping. Carbon fiber has the additional advantage of moldability, giving designers the ability to create a frame shape with superior aerodynamic properties than can be achieved with traditional metal tubing.
Carbon fiber is also the leader in weight savings. Producing a sub-3 lb. frame from aluminum or titanium is difficult, and impossible from steel. Carbon fiber allows manufacturers to make frames that weigh less than a kilogram--2.2 lbs. More and more carbon fiber is the first choice for superior performance. Of course, performance isn't cheap and carbon fiber bicycle frames can sometimes cost upwards of $5000.
Each of the materials has its place in cycling. Aluminum and steel lead the low-cost options; aluminum is lighter, but steel can offer a more artful appearance. Titanium offers the advantage of both artful appearance and low weight, but no one ever accuses titanium with affordable. For those looking for a frame that can offer the greatest performance benefits, carbon fiber is the clear leader.