Editor’s note: This story first appeared in Bicycle Times issue #15, published in February 2012. Words by Jeff Archer. Photos by Wes Stearns.
Stereotypes abound in the bicycle industry, especially when it comes to the properties of frame materials. You know the ones: Steel is heavy, aluminum is stiff and carbon is the wonder material. As with most stereotypes, these are rooted in fact, but as anybody who rides knows, there is more to a bike than what the frame is made out of.
This will be the first in a series of articles exploring frame materials and offering examples of a bike made from each. Since more bikes have been made out of it than any other material, we will begin with steel.
Steel has the longest history of any material in the bike industry and is still the first choice of most custom frame builders. The alloyed steel found in most quality bike frames is primarily iron with a small amount of other elements mixed in, such as chromium and molybdenum (e.g. “chromoly”). Steel has a relatively high density when compared with other materials, approximately twice that of titanium and triple that of aluminum, which puts it at a weight disadvantage. One the plus side, steel is stiffer than aluminum and titanium in roughly the same ratios, so the strength-to-weight ratio of the three materials is very similar.
Steel frames will typically be built with smaller (less than 1.25 inch) diameter tubes, which can limit the frame’s rigidity but results in a supple ride. One way to increase the rigidity is to increase the diameter of the tubing. But because of the density of steel, a large diameter tube can get heavy unless the wall thickness is minimized. The problem with thin walls is that they create the potential of a tube collapse from even a small ding. Take the example of a thin-walled beer can: It can support your weight if you stand on it—until you tap the side, causing it to collapse.
Steel does have a long fatigue life and tends to bend rather than break, which is a desirable trait. Overall, steel is relatively easy to build with and can be fillet brazed, TIG welded or joined with lugs. It is also plentiful, inexpensive, repairable, durable and easy to fabricate. All of these traits combine to justify the “steel is real” slogan.
One of the quintessential steel bikes is the Schwinn Paramount. Conceived in 1938 as a USA-built bike to rival the best in the world, the Paramount was the top model in the Schwinn line for decades. The Paramount’s popularity reached its peak during the bike boom of the early 1970s. This particular bike was built in 1972 and has been fully chrome-plated. The chrome bikes required extra finish work, since blemishes couldn’t be hidden under paint and primer. It was purchased from the grandson of the original owner and came with all the paperwork and receipts. Everything, except the tires, is original, including oft-replaced wear items such as the cables and handlebar tape. The generator light and saddlebags were purchased new with the bike. It isn’t often you see a high-performance bike with original reflectors and touring accessories—it was obviously a much-cherished bike.
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