From the 1930s to the 1970s, this was the way high-quality bikes were made: Lugs, which are cast steel sockets, were fitted to the corners of the frame. Next, metal tubes were fitted to the lugs and held in place by brazing or silver soldering.
The classic English roadster produced from the 1930s through the1960s, had a lugged steel frame, with an internal 3-speed hub, and upright riding position.
For the first half of the 20th century, an "American bicycle" had balloon tires, a single speed, a rear coaster brake, and was designed to appeal to children too young to drive a car.
Schwinn made tandems on their Paramount production line from 1969-1979. The Paramount name was reserved for top-of-the-line Schwinns. Today, this factory continues to make bicycles under the name Waterford Precision Cycles.
In the late 1980s, Alaskan frame builders began experimenting with custom components and design to create a bicycle with a large tire contact patch for greater control on snow; as a result, the fatbike was born.
Trek was an early adopter of carbon-fiber technology. In 1992 it unveiled its first US-made, full carbon-fiber-framed bicycles, the 5200 and the 5500, featuring a new technology called OCLV.